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The mechanical efficiency of human locomotion has been studied extensively. The mechanical efficiency of the whole body occasionally exceeds muscle efficiency during bouncing type gaits. It is thought to occur due to elasticity and stiffness of the tendinomuscular system and neuromuscular functions, especially stretch reflexes. In addition, the lower limb joint kinetics affect mechanical efficiency. We investigated the impact of varying external work on mechanical efficiency and lower limb kinetics during repeated sledge jumping. Fifteen male runners performed sledge jumping for 4 minutes at 3 different sledge inclinations. Lower limb kinematics, ground reaction forces, and expired gases were analyzed. Mechanical efficiency did not differ according to sledge inclination. Mechanical efficiency correlated positively with the positive mechanical work of the knee and hip joints and the negative contribution of the hip joints. Conversely, it correlated negatively with both the positive and negative contributions of the ankle joint. This may be attributable to the greater workload in this study versus previous studies. To achieve greater external work, producing more mechanical energy at the proximal joint and transferring it to the distal joint could be an effective strategy for improving mechanical efficiency because of the greater force-generating capability of distal joint muscles. [ABSTRACT FROM AUTHOR]

Context: The hip adductor and abductor muscles play vital roles as stabilizers in the lower-extremity. Their activation during soccer-specific actions is essential, but local muscular fatigue can hinder athletic performance and increase the risk of injury. Design: This study aimed to observe the variations in frontal plane hip strength in female college soccer players before and after a high-workload soccer-specific training session. Furthermore, the study sought to compare the relative changes in hip strength with the internal and external load measures obtained during that session. Methods: Twenty female college soccer players participated in a retrospective observational study. Isometric hip adductor and abductor strength were measured before and after a training session in the college spring season. Measurements were taken with a handheld dynamometer (MicroFET 2) while the players were supine. Global positioning system sensors (Catapult Vector S7), commonly worn by players during training sessions and competitive matches, were used to measure external and internal loads. Statistical analyses were performed using paired samples t test to assess hip adductor and abductor strength changes before and after the training session. Spearman rank was used to identify correlation coefficients between global positioning system data and isometric hip strength. Results: The findings revealed significant decreases in the strength of the right hip adduction (P =.012, −7% relative change), right abduction (P =.009, −7.6% relative change), and left abduction (P =.016, −4.9% relative change) after the training session. Furthermore, relative decreases in hip isometric adduction and abduction strength are related to the distance covered at high speeds. Conclusion: The results of this study highlight that hip isometric adduction and abduction strength tend to decrease after exposure to high workloads during soccer-specific training. [ABSTRACT FROM AUTHOR]

Context: Piriformis syndrome is often associated with muscle spasms and shortening of the piriformis muscle (PM). Physical therapy, including static stretching of the PM, is one of the treatments for this syndrome. However, the effective stretching position ofthe PM is unclear in vivo. This study aimed to determine the effective stretching positions of the PM using ultrasonic shear wave elastography. Design: Observational study. Methods: Twenty-one healthy young men (22.7 [2.41 y) participated in this study. The shear elastic modulus of the PM was measured at 12 stretching positions using shear wave elastography. Three of the 12 positions were tested with maximum internal rotation at 0°, 20°, or 40° hip adduction in 90° hip flexion. Nine of the 12 positions were tested with maximum external rotation at positions combined with 3 hip-flexion angles (70°, 90°, and 110°) and 3 hip-adduction angles (0°, 20°, and 40°). Results.' The shear elastic modulus of the PM was significantly higher in the order of 40°, 20°, and 0° of adduction and higher in external rotation than in internal rotation. The shear elastic modulus of the PM was significantly greater in combined 110° hip flexion and 40° adduction with maximum external rotation than in all other positions. Conclusion.- This study revealed that the position in which the PM was most stretched was maximum external rotation with 110° hip ftexion and 40° hip adduction. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the preliminary effects of movement pattern training (MoveTrain) versus strengthening/flexibility (standard) treatment on hip and pelvic biomechanics in patients with chronic hip-related groin pain. This is a secondary analysis of data collected during a pilot randomized clinical trial. Thirty patients with hip pain, between the ages of 15 and 40 years, were randomized to MoveTrain or standard. Both groups completed 10 treatment sessions over 12 weeks along with a daily home exercise program. Three-dimensional motion analysis was used to collect kinematic and kinetic data of the pelvis and hip during a single-leg squat task at pretreatment and immediately posttreatment. Compared with the standard group, the MoveTrain group demonstrated smaller hip adduction angles (P =.006) and smaller hip external adduction moments (P =.008) at posttreatment. The desired changes to hip joint biomechanics, as found in this study, may require specificity in training that could allow health care professionals to better customize the rehabilitation of patients with hip pain. These findings can also be applied to the design and implementation of future clinical trials to strengthen our understanding of the long-term implications of different rehabilitation techniques for patients with hip pain. [ABSTRACT FROM AUTHOR]

Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was.43 during the landing phase (P =.04) and with peak hip internal rotation was −.68 (P <.001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r =.40, P =.05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test. [ABSTRACT FROM AUTHOR]

Previous research has shown that there are differences in mechanical energy, kinematics, and muscle activation when comparing walking on level and incline surfaces, especially on inclines above 15%. Muscle activations are significantly different while walking on extreme inclines, suggesting a different coordination pattern. We utilized continuous relative phase to assess walking kinematic coordination with respect to increased incline angles. Twelve healthy, college-aged individuals walked for 7 inclines of 1 minute each on a motorized treadmill at 3 mph at 0%, 5%, 10%, 15%, 20%, 25%, and 30% inclines. Kinematic data were collected during the last 20 seconds of each stage (120 Hz). Segmental and joint angles and angular velocities in the sagittal plane were calculated, from which continuous relative phase was determined for 3 joint couples: hip–knee, hip–ankle, and knee–ankle. There were significant differences in the coordination patterns during the first part of the contact phase in the hip–knee and hip–ankle couplings between the 0% and 30% inclines, with all 3 joint couplings becoming more in-phase at inclines above 15%. Importantly, the hip–knee coupling changed significantly from more out-of-phase to more in-phase between 10% and 15% incline. Shifting lower-extremity joint coordination in response to extreme inclines identifies potential coordinative strategies to achieve steep walking. [ABSTRACT FROM AUTHOR]

Context: To assess the reliability of a remote 2D markerless motion tracking method (Kinovea) to quantify knee and hip angles during dynamic tasks. Methods: Fourteen healthy adults performed body weight squats and lateral lunges while video recording themselves at home. Knee and hip angles were quantified in the sagittal plane for the squats and in the frontal plane for the lateral lunges. Two students each performed the video analysis procedure twice, 2 weeks apart. Intraclass correlation coefficients were used to calculate the intrarater and interrater reliability for angles at maximum depth. The intrarater and interrater agreement over the joint angle-time signals were quantified using a validation metric; an acceptable agreement threshold was set at a validation metric of 0.803 or higher. Standard error of measurement (SEM) was also calculated. Results: Reliability was good to excellent (intraclass correlation coefficients = .80-.98) for all angle comparisons at maximum depth. The agreement over the entire joint angle-time signal was acceptable for all squat variables except for the interrater hip angle comparison (validation metric = 0.797). None of the lateral lunge variables met the threshold of acceptable agreement. The mean SEM across participants for all joint angle-time signal and for maximum depth was acceptable (<5°) for all measurements (SEM = 1.2°-4.9°). Conclusions: Overall, the reliability, agreement, and SEM quantified in this study support the integration of remote methods to quantify lower-extremity kinematics into research and clinical practice. [ABSTRACT FROM AUTHOR]

Context: Hip and groin injuries are common in field sports such as football, with measurement of hip strength and range of motion (ROM) recommended for assessment of these conditions. We aimed to report hip strength, hip ROM, and functional task performance in young elite Australian football athletes. Design: Cross-sectional study. Methods: Fifty-eight newly drafted Australian Football League athletes completed hip abduction, adduction, internal rotation, external rotation, and flexion strength testing with an adjustable stabilized or hand-held dynamometer. Hip internal rotation and external rotation, bent knee fall out, and ankle dorsiflexion ROM were also measured. Players completed hop for distance, side bridge, and star excursion balance functional tests. We compared findings between the dominant and nondominant limbs. Results: We found small deficits unlikely to be clinically meaningful in the dominant limb for hip abduction and adduction strength, and a small deficit in the nondominant limb for external rotation strength and side bridge time. Athletes had lower hip internal rotation (mean difference 2.56°; 95% confidence interval, 0.87 to 4.26) and total rotation ROM (2.03°; 95% confidence interval, 0.06 to 4.01) on the dominant limb. Conclusions: There were no meaningful differences between dominant and nondominant limbs for hip strength, ROM, or functional tests. Our results may be used for benchmarking young male Australian football athletes when targeting optimal strength and returning from injury. [ABSTRACT FROM AUTHOR]

Background Stretching programs are designed to improve hamstring flexibility by attempting to mechanically increase the length of the target tissue. However, other manual treatment approaches such as those utilized in Total Motion Release (TMR®), could be beneficial by identifying body asymmetries to assess and treat soft tissue impairments leading to diminished extensibility. Purpose The purpose of this study was to determine the effectiveness of the TMR® Fab 6 assessment and treatment to increase hamstring flexibility in healthy participants following one session of TMR®. Study Design Observational Cohort study Methods A convenience sample of 20 healthy participants (10 males, 10 females) were recruited from three institutions. Following collection of demographic information and a brief medical history, each participant performed a five minute warm-up on the stationary bike at a moderate intensity (80-90 RPMs) followed immediately by the bilateral performance of the Active Knee Extension Test (AKET) and Passive Straight Leg Raise (PSLR) to assess hamstring muscle length. Participants were randomly placed in the TMR® or control group. The TMR® group completed the "Fab 6" evaluation and treatment, while the control group performed one repetition of standing active hip flexion every 30-seconds for 15-minutes with both knees in full extension. Upon completion of treatment, control and TMR® groups were immediately re-evaluated on the AKET and the PSLR in the same order and fashion as baseline testing. Participants were asked to return in 24-hours for the same objective measurements as previously described. Results A significant time by group interaction was identified across all variables (p < 0.001) for AKET and PSLR except the PSLR preferred leg from post-treatment to 24hr follow-up. The most significant increase in the AKET occurred in the TMR® group between baseline and post-treatment of the non-preferred leg (12.15°±2.94) when compared to the control group (7.15°±1.56). [ABSTRACT FROM AUTHOR]

Introduction: Vitamin c can relieve the pain after other diseases, but there are no studies on whether vitamin C can relieve the pain after hip replacement. The purpose of this paper is to study whether vitamin C can relieve the pain after total hip replacement. Purpose: In this prospective, double-blind, placebo-controlled, randomized trial, 100 patients receiving THA at our hospital were randomly assigned to vitamin c or control groups. During the operation, the vitamin C group will receive intravenous injection of 3 g vitamin C, and the control group will receive 3 g placebo. If the patient has postoperative pain, 10 ml subcutaneous injection of morphine will be required as a rescue analgesic. The primary outcome was the amount of postoperative injection of morphine as a rescue analgesic and expression of inflammatory factors, and the secondary outcome was postoperative pain and hip recovery as assessed by visual analog scale (VAS). Results: The dosage of subcutaneous injection of morphine was significantly reduced in vitamin C group. VAS pain scores at rest and exercise were lower in the vitamin C group 24 h after surgery, and hip motion was better 24 h after surgery, but there was no significant difference between the two groups 24 h after surgery.Nonetheless, the overall changes in morphine usage and VAS scores did not surpass the established minimal clinically important differences (10 mg for morphine consumption; 1.5 at rest and 1.8 during movement for VAS scores). Conclusion: Adding intravenous vitamin c to multimodal analgesia significantly improved morphine consumption, VAS pain score, and functional recovery. However, it is recommended that single intravenous administration of vitamin C during the perioperative period may achieve better pain relief for patients after THA. [ABSTRACT FROM AUTHOR]

Hip strength has been shown to influence the incidence of injury in women's football. The first objective of our study was to examine the differences in isometric strength of the adductors and abductors between two test positions (0° vs. 45° hip angle). Our second objective was to verify the sensitivity of the two test positions in discriminating between women footballers with and without a history of groin pain in the last twelve months. One hundred and one elite players from the Slovenian women's football league were tested. The isometric strength of the adductors, abductors, and the ratio between hip abductor and adductor strength in two different test positions were assessed. We found statistically significant differences (p < 0.05; effect size range 0.12–0.13) between the two test positions in hip adduction, abduction strength, and abductor/adductor strength ratio. The ROC analysis showed that only the abductor/adductor strength ratio at the 0° hip angle position can differentiate between players with and without a history of groin pain, with an optimal cut-off point of ≤ 1.01 (p < 0.05; AUC = 0.734). The results should help practitioners plan hip strength training for returning to sport or preventing groin pain among women football players. [ABSTRACT FROM AUTHOR]

Isokinetic knee tests mostly evaluate reciprocal concentric-concentric flexor-extensor movements in a seated position. Discrete tests generate higher moments, but time requirements impede their widespread implementation. This study examined if hip angle (flexed vs. extended) and test modality (discrete vs. reciprocal) affect camera-based data (100 fps). Sixteen healthy males performed concentric (con) and eccentric (ecc) isokinetic knee flexor (H) and extensor (Q) movements (60°/s). Peak moments and contractional work of discrete and reciprocal tests (QconQecc, HconHecc) strongly correlated for extended (Q:91%≥R2≥71%; H:95%≥R2≥87%) and flexed hip (Q:88%≥R2≥70%; H:81%≥R2≥75%) without significant differences (p>0.05) between test modalities. Discrete and "traditional" seated QconHcon-tests revealed substantially lower correlations for extended (Q:44%≥R2≥43%; H:55%≥R2≥54%) and flexed hip (Q:81%≥R2≥77%; H:48%≥R2≥47%). Although most mean values did not significantly differ, moderate correlations were predominant and the respective limits of agreement demonstrated considerable effects of hip angle and test modality. These insights assist practitioners in interpreting isokinetic data of different test procedures. If time constraints prevent discrete knee tests (gold standard), concentric-eccentric movements provide highly correlated outcomes, independent of the hip angle. [ABSTRACT FROM AUTHOR]

Background: Displaced femoral neck fractures frequently result in considerable patient morbidity, with complications such as postoperative femoral neck shortening occurring in up to 39.1% of cases. This shortening is associated with reduced hip function and mobility. The Femoral Neck System (FNS), which allows for controlled sliding to facilitate fracture reduction and healing, may mitigate these issues. However, the ideal sliding distance to balance fracture healing and minimize complications is not well defined. Methods: We performed a retrospective cohort study of 179 patients who underwent FNS fixation for displaced femoral neck fractures at our institution from September 2019 to September 2023. Patients were categorized into three groups based on the intraoperative sliding distance allowed by the FNS: the Minimal Slide group (≤ 5 mm), the Moderate Slide group (> 5 to ≤ 10 mm), and the Extensive Slide group (> 10 to 20 mm). Primary outcomes included postoperative femoral neck shortening, the incidence of moderate to severe shortening, time to fracture union, and hip joint function as assessed by the Harris Hip Score (HHS) and the Parker Mobility Score. Secondary outcomes included complication rates such as implant cut-out, nonunion, avascular necrosis of the femoral head, and the need for secondary surgery. Results: The Extensive Slide group of moderate to severe shortening at 32.31%, which was 1.59-fold and 8.88-fold that of the Moderate Slide (20.34%) and Minimal Slide group's (3.64%), respectively (P < 0.01). The sliding predominantly occurred within the first three months postoperatively and had substantially ceased by six months. At one year postoperatively, the median shortening was 2.7 mm (IQR, 0.7 to 3.5 mm) for the Minimal Slide group, a value that was notably lower compared to the 3.2 mm (IQR, 2.4 to 4.6 mm) for the Moderate Slide group and the 3.5 mm (IQR, 1.3 to 8.1 mm) for the Extensive Slide group. The average time to achieve union was similar across all groups, with no significant differences. Functional outcomes, as assessed by the Harris Hip Score (HHS) and the Parker Mobility Score, the Harris Hip Score (HHS) demonstrated statistical significance, the Parker Mobility Score did not reach statistical significance. Conclusions: Restricting FNS slide to ≤ 5 mm in surgery may reduce shortening, improve hip function, and not hinder fracture healing or implant stability. Considering the key 3-month sliding timeline postoperatively is advisable in clinical practice. Further research with a broader patient cohort is vital to confirm these findings and to anchor them in evidence-based practice. [ABSTRACT FROM AUTHOR]

This study investigated the kinematic (KmS) and kinetic (KnS) strategies integrating the trunk and lower limbs to achieve maximal kicking performance. Although strategies consisting of individual joint movements or moments are known, strategies combining joint movements or moments of the trunk and lower limbs have been less studied. Fifty adult amateur soccer players were assessed. Peak joint angles and moments of the trunk, the hip of the supporting limb, the hip and knee of the kicking limb, and the velocities of the foot and ball were recorded. Canonical Correlation Analysis evaluated relationships between sets of variables. A combination of greater hip extension and knee flexion of the kicking limb, as a KmS, correlated with better kick performance (Rc = 0.60, p = 0.004). Furthermore, a combination of larger moments of trunk flexion and rotation, internal rotation of the supporting hip, hip flexion, and knee extension of the kicking limb, as a KnS, were associated with better performance (Rc = 0.74, p < 0.001). The explained variance was 43% for the KmS and 59% for the KnS. In amateur players, the KmS for better kick performance involved greater hip and knee movement of the kicking limb, while the KnS involved greater moments at the trunk and both lower limbs. [ABSTRACT FROM AUTHOR]

The primary aims of the study were to perform a descriptive analysis of hitting energetics off a pitching machine and to compare between the rear- and lead-side lower and upper extremities. Eighty-five high school to minor league baseball athletes participated. Five full-effort swings off a pitching machine with the fastest exit velocity were used for analysis. Energy flow was quantified using a segment power analysis. Wilcoxon signed-rank test revealed significant differences between rear- and lead-side energetics during both swing phases. During the stride, the rear knee and shoulder generated more energy than the lead side. Throughout the swing phase the lead knee, hip, and elbow generated more energy than the rear side, but at the shoulder the rear side generated significantly more energy than the lead. Most intriguing, differing energy transfer directions between the rear and lead knee and shoulder joints were reported. Furthermore, descriptive results revealed energy is predominantly transferred across the knee, shoulder, and elbow joints, while the hips primarily display energy generation. The descriptive nature of the study provides a foundation for future research and can be used as a resource for training personnel to design effective training protocols aimed at maximizing performance. [ABSTRACT FROM AUTHOR]

Recreational cyclists with a transtibial amputation (TTA) exhibit kinematic and kinetic asymmetries between their biological and affected legs, which may worsen efficiency. Use of unequal crank arm lengths and/or a cycling-specific prosthesis (CSP) could reduce mechanical asymmetries and improve efficiency. Purpose: We determined the effects of shorter affected side (AS) crank arm lengths and cycling with two different prostheses on joint and crank power, asymmetry, and net efficiency. Methods: Twelve participants with a TTA rode at 1.5 W·kg−1 with equal (175 mm) and shorter AS crank arms (160, 165, 170 mm) using a daily-use prosthesis and CSP. We used statistical parametric mapping to determine differences in instantaneous joint and crank power between prostheses and linear mixed-effects models to compare average joint and crank power, asymmetry, and net efficiency. Results: Shorter AS crank arm lengths reduced the magnitude of peak positive (P ≤ 0.001) and negative (P < 0.001) crank power on the AS. Use of a CSP increased the magnitude of peak positive knee power (P < 0.001) and decreased the magnitude of peak negative crank power (P < 0.001) on the AS compared with a daily-use prosthesis. Shorter AS crank arm lengths while using a CSP reduced average hip joint (P = 0.014) and hip transfer (P = 0.025) power asymmetry from 35% to 20% and 118% to 62%, respectively. However, we found no significant differences in AS average joint or crank power, knee joint or crank power asymmetry, or net efficiency. Conclusions: Cycling at 1.5 W·kg−1 with unequal crank arm lengths and CSP improves hip joint power and hip transfer power asymmetry but does not alter crank asymmetry or net efficiency for recreational cyclists with a TTA. [ABSTRACT FROM AUTHOR]

Background: Pain after total hip arthroplasty (THA) for femoral neck fracture (FNF) can be severe, potentially leading to serious complications. PENG block has become an optional local analgesic strategy in hip fracture surgery, but it cannot provide effective pain relief for the posterior capsule of the hip joint. Therefore, we modified the traditional sacral plexus nerve block and named it Posterior Hip Pericapsule Block (PHPB) to complement the blockade of the relevant nerves innervating the posterior hip capsule region. Thereby, we detail the analgesic effect of PHPB combined with PENG block on five hip fracture patients and the effect on their hip motor function. Methods: This case series was conducted from December 2023 to February 2024. We performed ultrasound-guided PHPB combined with PENG block on five patients with hip fractures. Numerical Rating Scale (NRS) pain scores at rest and maximum NRS pain scores during limb movement of the five patients were recorded within 48 h after surgery. Their hip flexion, abduction, adduction, keen flexion and quadriceps muscle strength were also recorded. Serious postoperative complications, including wound infection, hematoma formation, or nerve injury, were recorded. Results: They experienced effective pain control within 48 h postoperatively, with NRS pain scores at rest decreasing from 3.0 (3.0, 4.5) to 0.0 (0.0, 1.0) and maximum NRS pain scores during limb movement from 8.0 (7.5, 8.5) to 1.0 (0.5, 2.0). They can autonomously perform hip flexion, abduction, adduction, and knee flexion within 48 h postoperatively without any signs of movement disorders or quadriceps muscle weakness. No severe postoperative complications, such as wound infections, hematoma formation or nerve damage, were observed in any of the patients. Conclusions: Ultrasound-guided PENG block combined with PHPB provided effective analgesia for hip fracture patients in the perioperative period. It maintained hip joint motor function and quadriceps muscle strength within 24 h after THA. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the relative muscular effort (RME) of the hip and knee extensor and ankle plantarflexor muscle groups during the back squat (BS) and split squat (SS) exercises across four external load conditions. Motion capture and force plate data were collected as participants performed the BS and SS at 0%, 25%, 50%, and 75% of their body-mass. These data were used to calculate net joint moments (NJM) at the hip, knee, and ankle of the front leg during the SS and the matched leg during the BS. A musculoskeletal model, which accounted for force-length-velocity properties of 52 muscles, was used to estimate the maximal possible NJM (NJMmax) of the hip and knee extensor and ankle plantarflexor muscle groups. RME was calculated as the ratio between NJM and NJMmax, and compared across exercises and loads. The results indicated that while hip extensor RME increased across all loads, the increases in hip extensor RME were disproportionately greater during the SS at loads of 50% and 75%. Knee extensor RME increased linearly across loads and did not differ between exercises. These results provide coaches and athletes with detailed information about how to optimise resistance training specificity. [ABSTRACT FROM AUTHOR]

Background: There is little known about translation of the hip and the relationship with hip rotation and morphology in asymptomatic patients. Hypotheses: (1) Femoral head would exhibit significant translations in asymptomatic hips, (2) femoral head translations would correlate to femoral rotations, and (3) range of femoral head translations would correlate to hip morphology. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 11 individuals (age, 23-47 years; 64% female) with asymptomatic hips underwent hip magnetic resonance imaging (MRI) in the following postures: neutral (supine), midflexion, maximum-flexion, internal rotation, internal rotation + midflexion, internal rotation + maximum-flexion, adduction, flexion-abduction-external rotation (FABER), extension, and lateral abduction. All rotations were passive. MRI-generated 3-dimensional hip models were used to quantify femoral rotations and translations. Femoral head diameter, acetabular diameter, lateral center-edge angle, alpha angle, femoral anteversion, acetabular version and inclination, and neck-shaft angle were measured from MRI. A t test was used if measured translations were statistically significant. Linear regression was used to assess the associations between translation and rotation. Pearson correlation was used to assess the relationships between hip anatomy and range of femoral head translations. Results: In all tested positions, the femoral head translated anteriorly by 2 ± 1 mm (maximum 5 mm, P <.001), posteriorly by 1 ± 1 mm (maximum 6 mm, P <.001), superiorly by 2 ± 2 mm (maximum 7 mm, P <.001), inferiorly by 2 ± 2 mm (maximum 6 mm, P <.001), laterally by 1 ± 1 mm (maximum 4 mm, P <.001), and medially by 2 ± 1 mm (maximum 5 mm, P <.001), relative to the rested supine position. Femoral flexion was associated with posterior translation of the femoral head (P =.038). Femoral abduction was associated with medial translation of the femoral head (P =.042). Higher femoral anteversion and smaller alpha angle were associated with a higher total magnitude of femoral head translation in the anterior-posterior direction (P <.04). Smaller femoral anteversion, higher acetabular inclination, smaller lateral center-edge angle, and lower neck-shaft angle were associated with a higher total magnitude of femoral head translation in the superior-inferior direction (P ≤.03). Conclusion: Our study demonstrated that, during passive physiologic movement, asymptomatic hips on average translated up to 2 mm (with up to 7 mm maximum translation in some positions), which is potentially related to hip rotations and morphology. Further investigations are warranted to understand the normal and pathologic hip translations and their impact on hip function (ie, instability and impingement). [ABSTRACT FROM AUTHOR]

Background: Surgical treatment of patients with proximal hamstring avulsions provides good results; however, less is known about the outcome in patients who are offered conservative treatment. Purpose: To investigate the effect of surgical or conservative treatment (decided by a shared decision strategy) of proximal hamstring avulsions. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 24 patients with magnetic resonance imaging–verified proximal hamstring avulsion were included and had either surgical treatment (11 patients, 45% women; mean age, 50 ± 16 years) or conservative treatment (13 patients, 46% women; mean age, 50 ± 17 years). At baseline, 6 months and 12 months, all patients answered the Perth Hamstring Assessment Tool (PHAT) (0-100 scale) and Hip Sports Activity Scale (0-8 scale). Patients had their maximal hip extension strength and maximal strength at 30° and 90° of knee flexion measured in newton meters per kilogram using a handheld dynamometer. A minimal important change in PHAT was considered >7 points and a minimal important change in strength was considered >0.15 N·m/kg, respectively. Results: The surgical group had a shorter time from injury to initiation of treatment compared with the conservative group (median: 15 vs 64 days; P =.02). The surgical group had a greater amount of retraction of the tendons compared with the conservative group (3 vs 2 cm; P =.04). From baseline to 12-month follow-up, the surgical and conservative groups improved their mean PHAT scores (35 points [95 CI, 24-45 points] and 20 points [95% CI, 9-31 points], respectively) reaching a median of 79 points (interquartile range [IQR], 66-95 points) in the surgical group and 75 points (IQR, 66-85 points) in the conservative group at the 12-month follow-up. Their Hip Sports Activity Scale levels at 12 months were 3 points (95% CI, 1-4 points) and 1 point (95% CI, 0-3 points) (not significant). Furthermore, the surgical and conservative groups improved their maximal hip extension strength by 0.61 N·m/kg (IQR, 0.42-0.80 N·m/kg) and 0.62 N·m/kg (IQR, 0.13-1.10 N·m/kg), respectively. Their maximal knee flexion strength at 30° improved by 0.52 N·m/kg (IQR, 0.29-0.74 N·m/kg) and 0.32 N·m/kg (IQR, 0.12-0.52 N·m/kg) and their maximal knee flexion strength at 90° improved by 0.28 N·m/kg (IQR, 0.19-0.37 N·m/kg) and 0.22 N·m/kg (IQR, 0.02-0.41 N·m/kg). At the 12-month follow-up, the side-to-side difference in maximal muscle strength was 6% and 7%, respectively, during hip extension and 19% to 25% and 16% to 17%, respectively, during knee flexion. Conclusion: Twelve months after treatment of proximal hamstring avulsion, good clinical outcomes were seen when using a shared decision strategy regardless of whether the strategy led to surgical or conservative treatment. [ABSTRACT FROM AUTHOR]

Background: The current standard for motion capture data collection in baseball biomechanics is marker-based optical motion capture. Recent advancement in markerless motion capture capabilities has greatly improved accessibility to in-game, high-precision motion capture data, but specific values may differ from markered systems, necessitating separate normative values. For future data comparison, reference data are needed. Purpose: To describe common kinematic variables in baseball pitching using an in-game markerless motion capture system. Study Design: Descriptive laboratory study. Methods: Kinematic data were collected in 2 collegiate stadiums in the National Collegiate Athletic Association Division I Southeastern Conference using 8 synchronized 300-Hz KinaTrax cameras placed around the playing field. The in-game biomechanics data of 51 pitchers from 5 different teams during the 2023 season were collected; only pitchers with >3 outings during the season were included. After averaging all available fastballs thrown in the first inning of a game, we analyzed triaxial trunk (rotation, flexion, and lean) and pelvic rotation angles in the global reference frame, as well as shoulder rotation, shoulder horizontal abduction, shoulder abduction, elbow flexion, stride knee flexion, and hip-shoulder separation. Results: A total of 509 fastballs were analyzed. Mean fastball velocity was 40.98 m/s (91.5 mph), with a vertical break of 42.0 ± 10.6 cm (16.5 ± 4.2 inches) and a horizontal break of 28.0 ± 11.1 cm (11.0 ± 4.4 inches). Mean stride length was 1.41 ± 0.08 m. The mean arm slot was 59.4°± 9.3°, and the mean upper arm slot was 72.9°± 9.3° at ball release. Additional normative time-series data are presented for commonly analyzed variables, and discrete metrics are provided at distinct time points in the pitching cycle. Conclusion: These data fill a need for separate norms for in-game, markerless motion capture performance metrics, and biomechanics for collegiate baseball pitchers to be used as reference values for researchers, coaches, and clinicians. Clinical Relevance: Clinicians should use these results as reference values to contextualize injury mechanisms and the injury-performance trade-off. These data will also educate clinicians on what athletes' bodies must do to perform when constructing plans of care and return-to-play timelines. [ABSTRACT FROM AUTHOR]

Objective: To retrospectively analyze and assess the long-term effectiveness of robotic navigation and traditional closed reduction internal fixation in the treatment of Delbet type II femoral neck fracture in children. Methods: A total of fifty-five patients diagnosed with pediatric Delbet type II femoral neck fracture, who were admitted to Foshan Hospital of Traditional Chinese Medicine between January 2018 and June 2022, were included in this study. Among them, 22 cases of nailing under robotic navigation were set as the observation group, and 33 cases of nailing under fluoroscopy of the C-arm machine were set as the control group. All patients had their femoral neck fractures closed and repositioned first. After confirming the satisfactory fracture repositioning under the fluoroscopic view of the C-arm machine, internal fixation was performed by inserting hollow compression screws in the corresponding surgical way.A comparative analysis was conducted between the two groups to assess the disparity in the amount of X-ray exposure during surgery, the number of guide pins inserted, and the duration of the surgical procedure. The quality of comparative fracture reduction was assessed according to the Haidukewych criteria on the first postoperative hip X-ray, and the parallelism and distribution of the comparative screws were measured. The incidence of hip function and postoperative complications according to the Ratliff criteria were evaluated between each of the subgroups at the final follow-up. Results: Comparison of general information, operation duration, and quality of fracture reduction between the two groups failed to reveal statistically significant results (P > 0.05). The observation group had a lower number of X-ray exposures and guide pin placements compared to the control group, and this difference was statistically significant (P < 0.05).At the last follow-up, the observation group exhibited superior screw parallelism and distribution, as well as hip joint function, compared to the control group, and this difference was statistically significant (P < 0.05). The incidence of complications in the observation group was lower than that in the control group; however, the difference was not statistically significant (P > 0.05). Conclusion: Closed reduction and internal fixation under orthopedic robot navigation can achieve better long-term efficacy in treating Delbet type II femoral neck fracture in children. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbopelvic movement patterns during prone hip extension has been proposed as a clinical screening method for trunk muscle dysfunction in patients with chronic low back pain (CLBP). However, correlations between trunk muscle onset and pelvic kinematics have not been investigated. OBJECTIVE: To examine the correlation between trunk muscle onset and pelvic kinematics during prone hip extension in participants with CLBP. METHODS: Fifteen patients with CLBP and 15 healthy individuals participated. We evaluated the muscle activities of the lumbar multifidus, the longissimus, and the semitendinosus via electromyogram and the displacement angles of the pelvic tilt, oblique and rotation. RESULTS: The onset of the multifidus at the ipsilateral side of hip extension was significantly delayed in the patients with CLBP compared to the control group (P < 0.001). The onset of the ipsilateral multifidus in the control group was significantly correlated with increased anterior pelvic tilt angle (P = 0.019, r = 0.597), whereas no significant correlation was observed in the CLBP group (P = 0.810, r = - 0.068). CONCLUSION: The results suggest that pelvic kinematics during prone hip extension does not predict the delayed trunk muscle onset in patients with CLBP. [ABSTRACT FROM AUTHOR]

There are different ways to deliver external focus (EF) and internal focus (IF) instruction. Understanding each modality better will help to develop more effective interventions to reduce injury risk. To investigate the difference in landing biomechanics between participants who received EF and IF instruction and control participants. A secondary aim was to evaluate participant perceptions of focus of attention. Randomized controlled trial. Laboratory. Forty-one healthy women (EF: n = 14, 23.0 ± 2.9 years, 1.69 ± 0.07 m, 64.0 ± 6.8 kg; IF: n = 15, 22.9 ± 3.2 years, 1.66 ± 0.08 m, 66.2 ± 12.4 kg; control: n = 12, 21.1 ± 2.9 years, 1.67 ± 0.11 m, 74.3 ± 15.1 kg). Participants scoring greater than or equal to 5 on the Landing Error Scoring System were allocated into the EF, IF, or control group. Knee and hip flexion and abduction were collected pre- and postintervention during 5 drop vertical jumps. For the intervention, each group was provided separate instructions. In between the intervention jumps, participants answered, "What strategy were you focusing on when completing the previous jump-landing trials?" Postintervention minus preintervention change scores were calculated, and separate 1-way analysis of variance assessments were performed to determine differences in the dependent variables. Individuals in the EF group had a greater change in hip and knee flexion angles than individuals in the control group. There was no significant difference between the EF and IF groups for any variables. There were no significant differences in frontal plane variables. In the EF group, 71.4% aligned with the instructions given; in the IF group, 80% aligned; and in the control group, 50% aligned. External focus instruction may not produce immediate changes in movement compared with IF instruction. Hip and knee flexion were greater in the EF group than in the control group but was not better than that in the IF group. Clinicians should provide instructions to patients, but the mode of instruction may not be as critical to see positive biomechanical changes. Patients may not always focus on the instruction being given; therefore, the relationship between instruction and patient experience should be further explored. [ABSTRACT FROM AUTHOR]

Whereas prolonged static stretching (SS: >60-seconds per muscle) can increase range of motion (ROM) for up to 2-hours, it can also decrease maximal voluntary isometric contraction (MVIC) forces, countermovement (CMJ) and drop jump (DJ) heights, and muscle activation immediately after the stretching exercise. When an appropriate SS duration (<60-seconds per muscle) is incorporated into a dynamic warm-up, performance decrements are often trivial. However, there is a lack of studies that observed the effects of extensive SS (180-seconds) 2-hours prior to a dynamic warm-up. The objective was to investigate ROM and performance effects of prolonged SS, 2-hours prior to a traditional warm-up. This study investigated 9 female and 8 male healthy recreationally active, young adult participants on the effects of prolonged SS (180-seconds per muscle) of the quadriceps and hamstrings, 2-hours before a traditional warm-up compared to an active control condition on hip flexion ROM, knee extension and flexion MVIC forces, CMJ, DJ, and quadriceps and hamstrings electromyography (EMG). There were no significant changes in knee flexion/extension MVIC forces, EMG, CMJ, or DJ height. However, there was significant, small magnitude (p = 0.002) greater post-warm-up left hip flexion ROM (115.4° ± 17.2) than pre-SS (108.9° ± 17.13, Effect size [ES]: 0.28) and control post-warm-up (p = 0.05, ES: 0.31, 109.5° ± 20.55). Similarly, right hip flexion ROM (117.2° ± 16.5) also demonstrated significant small magnitude (p = 0.003) greater than the pre-SS (112.4° ± 18.4, ES: 0.22) and control post-warm-up (p = 0.046, ES: 0.33, 110.8° ± 20.5). Additionally, significant, large magnitude greater hip flexion ROM was observed with the women vs. men (ES: 1.29 -- 1.34). Significant hip flexion ROM increases were not accompanied by significant changes in knee flexion/extension MVIC forces, EMG, or jump heights, suggesting that extensive SS can positively impact ROM without performance deficits when followed by a traditional warm-up, 2-hours after SS. [ABSTRACT FROM AUTHOR]

Introduction: Maximal acceleration and deceleration tasks are frequently required in team sports, often occurring rapidly in response to external stimuli. Accelerating and decelerating can be associated with lower limb injuries; thus, knowledge of joint mechanics during these tasks can improve the understanding of both human high performance and injury mechanisms. The current study investigated the fundamental differences in lower limb joint mechanics when accelerating and decelerating by directly comparing the hip, knee, and ankle joint moments and work done between the two tasks. Methods: Twenty participants performed maximal effort acceleration and deceleration trials, with three-dimensional marker trajectories and ground reaction forces collected simultaneously. Experimental data were combined with inverse dynamics analysis to compute joint moments and work. Results: Net joint work for all lower limb joints was positive during acceleration and negative during deceleration. This occurred because of significantly greater positive work production from the ankle and hip during acceleration and significantly greater negative work production from all joints during deceleration. The largest contributions to positive work during acceleration came from the ankle, followed by the hip and knee joints, whereas the largest contributions to negative work during deceleration came from the knee and hip joints, followed by the ankle. Peak joint moments were significantly greater when decelerating compared with accelerating, except for the peak ankle plantar flexion and hip flexion moments, which were significantly greater when accelerating. Conclusions: Our findings may help to guide training interventions, which aim to enhance the performance of acceleration and deceleration tasks, while also mitigating the associated injury risk. [ABSTRACT FROM AUTHOR]

The study objective is to test general- and sport-specific adaption during a single training on the Flexibility Trainer. The device is designed to trigger residual muscle tone decreases of the hip-joint muscles by providing (nearly) isokinetic resistance during a full range of motion strength training in adduction/abduction and flexion/extension direction. Static hip flexion and abduction as well as kinematics of double side kicks were analysed on 15 participants before and after training (or rest for controls) to assess general flexibility and sport-specific movement range. Tests were recorded by a Vicon® motion capturing system. Static hip flexion and abduction as well as leg vector spreading angles (VSA) at different nodes of the kick were selected to determine adaptions of active and passive flexibility. Normalised hip joint moments, movement velocities and VSA were calculated to evaluate the training with the device. ANOVAs with 4-repeated measures and Friedman tests were performed to identify time differences and Bonferroni post-hoc test to identify between-subject effects. Significant differences were found for both static flexibility tests (Flexion = 13.65%; Abduction = 9.94%) and the VSA at specific action phases (≤15.15%). Results indicate that short-term adaptions when training with the Flexibility Trainer are exceeding comparable literature showing improved flexibility and sport-specific performance. [ABSTRACT FROM AUTHOR]

Background Established norms for fitness and performance measures are lacking in circus arts. These would assist healthcare professionals and coaches to screen for readiness to participate in training or performance, determine post-injury return to performance, and develop targeted conditioning programs. Purpose The purpose of this research was to establish norms for trunk and extremity physical exam and performance measures in circus artists by professional status, assigned sex at birth (ASAB), and age. Study Design Descriptive laboratory study Methods Circus artists (n=201; ages 13-69y; 172 females ASAB, 29 males ASAB) from 10 cities across the United States underwent a baseline physical examination including shoulder, hip and trunk measures of passive (PROM) and active (AROM) range of motion, measures of flexibility (shoulder and hip), strength (manual muscle tests, grip strength), cardiovascular fitness (3 minute-step test), balance (single limb and handstand), and performance, (pull-ups, and the closed kinetic chain upper extremity stability test [CKCUEST]). ANOVAs were used to determine between group differences by age and T-tests to discern differences by ASAB or professional status. Results Differences existed by professional status for shoulder external rotation PROM, hip PROM, hip flexibility, shoulder and abdominal strength, and cardiovascular fitness. Sex differences were seen in active scapular upward rotation, hip and shoulder PROM and flexibility, hip and grip strength, and for functional performance measures (pull-ups, CKCUEST). Differences by age were limited to active scapular upward rotation, shoulder PROM, flexibility and strength, cardiovascular fitness, and balance. Overall, professionals outperformed pre-professionals for lower abdominal strength, pull-ups, handstand balance, cardiovascular fitness, hamstring, and straddle flexibility. Generally, males ASAB demonstrated greater shoulder flexibility and upper body functional strength while females ASAB had greater hip and lumbar flexibility and hip strength. No measures showed consistent declines with increasing age, though some showed differences between adolescents and adults. Conclusion These normative values for physical characteristics and functional performance in pre-professional and professional circus artists may be used to guide screening for readiness to participate in advanced training or performance, return to performance after injury, and the development of targeted strength and conditioning programs. Level of Evidence 3 [ABSTRACT FROM AUTHOR]

Background During sprinting, the biceps femoris long head predominantly gets injured, while hamstring strengthening exercises predominantly activate the semitendinosus more effectively. Understanding how joint dominance influences hamstring activity may offer clarity on appropriate exercise selection in strengthening programs. Purpose This study compared three hip-dominant hamstring exercises: the rocker, perpetuum mobile fast and slow (PMfast and PMslow) and the Nordic Hamstring exercise (NHE) on their potential to simulate sprint-like activity and kinematics. Methods Muscle activity of the posterior kinetic chain (biceps femoris, semitendinosus, gluteus maximus, and medial gastrocnemius) was measured with surface electromyography (sEMG) during the exercises and treadmill running at 75% of the individual maximal sprint velocity in male athletes. sEMG data were normalized to maximal sprinting. 3D-motion capture was employed to assess hip and knee angles. Results Eight male athletes were included (age: 24.0 years ± SD 2.9; body mass: 76.8 kg ± 7.7; height: 1.79 m ± 0.08). Greater activity of the hamstrings occurred during the explosive exercises ranging from 63.9% [95%CI: 56.3-71.5%] (rocker) to 49.0% [95%CI: 40.4-57.6%] (PMfast) vs. 34.0% [95%CI: 29.1-38.9%] (NHE) to 32.1% [95%CI: 26.9-37.3%] (PMslow). The rocker showed greatest hamstring and gluteus maximus activity. Biceps femoris consistently showed greater activity than the semitendinosus across all exercises in peak (mean difference: 0.16, [95%CI: 0.07-0.26]) and average (mean difference: 0.06, [95%CI: 0.01-0.11]) activity. PMfast, PMslow and NHE demonstrated less hip flexion angle at peak hamstring activity than the rocker and high-speed running and every exercise showed less hamstring elongation stress than during high-speed running. Discussion Hamstring activity is comparable to high-intensity treadmill running for NHE and PMslow, and greater for the rocker and PMfast. Gluteus maximus activity varied, with the rocker and PMfast showing greater activity than in sprinting. All examined exercises demonstrated their peak activity at short hamstring muscle length. Level of evidence 3b [ABSTRACT FROM AUTHOR]

Context: Slideboards are commonly used in exercise programs, but there is limited information about how they affect muscle activities during exercise. We aim to compare the activation levels of quadriceps and hamstring muscles and hip- and knee-flexion angles during lunge and single-leg squat exercises between normal ground and slideboard in physically active individuals. Design: Cross-sectional study. Methods: Thirty healthy individuals (age: 23.83 [2.84] y, body mass index: 21.75 [1.72] kg/m2) were included in the study. Surface electromyography was used to measure vastus medialis, vastus lateralis, biceps femoris, and semitendinosus activation levels during reaching and returning phases of the forward, lateral, and back lunges and squats that were performed on the normal ground and slideboard. Exercises were performed at a slow pace (60 beats/min). Hip- and knee-flexion angles during the exercises were evaluated by using 2-dimensional motion analysis. Repeated measures of analysis of variance were used for statistical analysis. Results: Vastus medialis and vastus lateralis activation levels were greater during reaching and returning phases of the exercises on slideboard compared with normal ground (P <.05). However, semitendinosus and biceps femoris activity were greater only during the returning phase of the forward lunge (P <.001) and the returning phase of the back squat (P =.002, P =.009, respectively). Hip-to-knee flexion ratios were closer to 1 when the forward lunge (P <.001), back lunge (P =.004), and forward squat (P =.001) exercises were performed on a slideboard. Conclusion: In exercise programs that target the quadriceps and hamstring muscles, slideboards can be effectively used in exercise progressions as they can increase muscle activity. Moreover, squat and lunge exercises on slideboard with a slow pace may also be helpful for improving the balance between hip- and knee-flexion angles. [ABSTRACT FROM AUTHOR]

Single-leg landings with or without subsequent jumping are frequently used to evaluate landing biomechanics. The purpose of this study was to investigate the effects of subsequent jumping on the external knee abduction moment and trunk and hip biomechanics during single-leg landing. Thirty young adult female participants performed a single-leg drop vertical jumping (SDVJ; landing with subsequent jumping) and single-leg drop landing (SDL; landing without subsequent jumping). Trunk, hip, and knee biomechanics were evaluated using a 3-dimensional motion analysis system. The peak knee abduction moment was significantly larger during SDVJ than during SDL (SDVJ 0.08 [0.10] N·m·kg−1·m−1, SDL 0.05 [0.10] N·m·kg−1·m−1, P =.002). The trunk lateral tilt and rotation angles toward the support-leg side and external hip abduction moment were significantly larger during SDVJ than during SDL (P <.05). The difference in the peak hip abduction moment between SDVJ and SDL predicted the difference in the peak knee abduction moment (P =.003, R2 =.252). Landing tasks with subsequent jumping would have advantages for evaluating trunk and hip control as well as knee abduction moment. In particular, evaluating hip abduction moment may be important because of its association with the knee abduction moment. [ABSTRACT FROM AUTHOR]

Background: Hip muscle weakness is associated with many musculoskeletal conditions and athletic injuries. Isokinetic testing is often performed to measure a patient's strength or to assess treatment response. Patient sex and positioning during isokinetic strength testing may influence peak torque production and the agonist-antagonist peak torque ratios. However, different test positions are used clinically and in research to measure hip muscle strength. It is unknown how patient test position or sex impacts test results. Hypothesis/Purpose: The purpose of this study was to determine whether concentric isokinetic peak torques of sagittal and frontal plane hip muscles differ when tested in recumbent versus standing positions and if results were impacted by patient sex. Study Design: Cross-sectional observational Methods: Forty healthy adults (20 male, 20 female) participated. Concentric isokinetic hip torques of the hip flexors, extensors, abductors, and adductors were measured with participants in two positions (recumbent versus standing; 60°/second angular velocity). Peak torque values were normalized by body mass and height. Data were analyzed with mixed-model ANOVAs (sex x position). Effect sizes were examined using partial eta squared. Results: No significant interactions or main effects for sex were found. Significant main effects for position were found for hip extensor and abductor peak torques and for hip flexor-extensor ratio. Hip extensor peak torque was greater when tested supine versus standing with a large effect size (p=.02, effect size =.14). Hip abductor peak torque was greater when tested sidelying versus standing with a medium effect size (p=.03, effect size =.12). Hip flexor-extensor agonist-antagonist ratio was greater when tested standing versus supine with a large effect size (p<.001, effect size =.27). Conclusion: Hip extensor and abductor concentric isokinetic peak torques were greater when tested in recumbent versus standing positions. In contrast, hip flexor-extensor ratio was greater when tested in standing versus supine. Level of Evidence: 3 [ABSTRACT FROM AUTHOR]

Background: Trunk rotation during pitching correlates with pitching velocity and load on the joints of the upper limb. Trunk rotation is often focusing on during teaching the pitching motion. Athletes who exhibit early trunk rotation during pitching often have low thoracic spine rotational range of motion. The purpose of this study was to investigate the relationship between the range of thoracic spine rotation measured using the lumbar locked rotation test (LLR-t), hip-shoulder separation (H/S) and thoracic rotation angle at stride foot contact (SFC), and ball velocity. Study design: Descriptive laboratory study. Methods: Fifteen healthy male high school students belonging to a baseball club were recruited for participation. The throwing side and non-throwing side LLR-t was performed using an inclinometer. Hip-shoulder separation and thoracic rotation angle during SFC were measured using a pitching motion analysis application: Pitch AI. In addition, a tracking device specifically designed for pitching：Pitching2.0 was employed to measure ball velocity. Correlations between LLR angle, H/S, trunk rotation angles at SFC, and ball velocity were examined using Pearson's correlation coefficient. Result: There was a positive correlation（r=0.52，p=0.047） between the LLRt angle and H/S. Additionally, there was a negative correlation（r=-0.62, p =0.01） between the LLRt angle on the throwing side and thoracic rotation angle. There was a positive correlation(r=0.54, p=0.04) between ball velocity and H/S and a negative correlation(r=-0.56, p=0.03) between ball velocity and thoracic rotation angle during SFC. Conclusion: The LLR-t measures thoracic rotation angle with the pelvis-lumbar spine fixed. The results indicated that throwing side LLR was related to the thoracic angle during SFC and hip-shoulder separation. Level of evidence: 3 [ABSTRACT FROM AUTHOR]

Purpose: The effect of cancellation and postponement of primary total hip arthroplasty (THA) or knee arthroplasty (TKA) on patient outcomes is unclear. The aim was to assess whether cancellation and delay to arthroplasty was associated with worse joint specific function and quality of life (QoL) 1-year postoperatively. Methods: A single centre retrospective case–control study was performed for all patients planned to undergo THA or TKA in 2019. A total of 3133 arthroplasties were scheduled for 2019 (1484 THA, 1649 TKA), of which 344 (11.0%) were cancelled (136 THA [9.2%], 208 TKA [12.6%]). Pre-operative and one-year post-operative EuroQol (EQ-5D) and Oxford hip (OHS) or knee (OKS) scores were collected. Results: The median time between the date of cancellation and the subsequent operation was 46.0 days for TKA and 45.5 days for THA. The cancelled group were more likely to be male (odds ratio [OR] 1.23, p = 0.03), older (mean difference [MD] 1.19, p = 0.03), with a higher ASA grade (OR 1.88 [ASA 3], OR 5.3 [ASA 4], p = 0.001) or planned for a TKA (OR 1.41, p = 0.003). There were no differences in pre-operative OKS (mean difference [MD] 0.19, p = 0.828) or EQ-5D (MD 0.028, p = 0.394) or in the one-year postoperative OKS (MD 1.51, p = 0.064) or EQ-5D (MD 0.041, p = 0.067) between groups undergoing TKA. However, cancelled THA patients had lower pre-operative OHS (MD 2.73, p = 0.018) and EQ-5D (MD 0.134, p = 0.0017) but at one-year postoperatively there was no difference in the absolute OHS (MD 2.07, p = 0.052) or EQ5D (MD 0.04, p = 0.142). The improvement in hip EQ-5D was greater (MD 0.096, p = 0.016) in the cancelled group. Conclusion: Cancellation and short delay did not influence joint specific outcome or QoL following THA or TKA at one-year. Preoperative hip specific pain, function and QoL were worse in cancelled THA patients, suggesting deterioration while waiting for their surgery, but this did not affect their postoperative outcome. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hip flexion angle-torque may not be measured accurately due to the measurement posture. OBJECTIVE: Maximum isometric hip flexion torque was measured while excluding the effects of postural retention function and compensatory motion. METHODS: Experiment 1: Maximum isometric flexion torque of the hip joint was measured at 0∘, 30∘, 60∘, 90∘, and 105∘ in 195 participants. Experiment 2: Maximum isometric hip flexion torque of 33 participants was measured in standing and supine position at 0∘ hip flexion and in end-sitting and supine position at 105∘. RESULTS: Experiment 1: No interaction was observed between sex and hip angle, and hip flexion torque was minimum at 0∘ hip flexion and maximum at 105∘ hip flexion in both sexes (p < 0.01). Experiment 2: An interaction between measurement position and hip angle was observed, with maximum isometric flexion torque being greater in the supine position than in the standing position (p < 0.01). Maximum isometric hip flexion torque was greater at 105∘ than at 0∘ flexion (p < 0.01). CONCLUSIONS: Maximum isometric hip flexion torque showed greater joint angle-torque characteristics in deep flexion than in shallow flexion of the hip when excluding the effects of postural retention function and compensatory motion. [ABSTRACT FROM AUTHOR]

Background: Resistance training with the barbell back squat (BBS) exercise is practiced in sports, recreation, and rehabilitation. Although extensively debated, it is commonly believed and recommended that maintaining a neutral lumbopelvic alignment during BBS is an important technical aspect that might reduce the risk of injury. There is limited knowledge of how objectively measurable factors affect the extent to which the lumbopelvic region moves into flexion during a BBS. Purpose: The aim of the study was to investigate the association among anthropometric measurements, range of motion in the hips and ankle joints, lumbopelvic movement control tests, and flexion of the lumbopelvic region during execution of the BBS. Study design: Observational, cross sectional. Methods: Eighteen experienced powerlifters and Olympic weightlifters were included and measurements of lumbopelvic movements were collected with inertial measurement units during BBS performed at 70 % of 1RM. Examination of anthropometric properties, range of motion in the hip and ankle joints, and lumbopelvic movement control tests were collected as independent variables. Linear regression analysis was used to investigate which independent variables were associated with lumbopelvic flexion during a BBS. Results: The linear regression showed that a higher range of motion in ankle dorsiflexion could statistically significantly explain an increased amplitude of lumbopelvic flexion during the BBS. Anthropometrics, range of motion of the hips, and performance in lumbopelvic movement control tests did not show any statistically significant associations. Conclusions: The results suggest that strength and conditioning professionals and clinicians who instruct and assess lifting technique in the BBS and/or use the BBS to assess performance or as an intervention should recognize that a higher range of motion in the ankle joints might affect lumbopelvic flexion during the BBS. In practice, the value of an individual assessment of lifting technique focusing on the goal of the movement should be emphasized. Level of Evidence: 3 [ABSTRACT FROM AUTHOR]

Background: While a high incidence of pickleball-related falls is reported, little is known regarding factors differentiating persons with and without a fall history during play. Purpose: This study aimed to determine differences between recreational pickleball players who fell while playing and those who did not. Additional aims were to determine reasons for falling and to investigate associations among assessed factors. Study design: Cross-sectional study. Methods: Participants completed a survey reporting age, fall history, and reasons for falling during play. Hip abduction strength, single leg squat form, ankle dorsiflexion, and change of direction time using a modified T-test on a pickleball court (i.e. pickleball T-test) were assessed. Results: Among the 92 individuals participating in the study, 42% reported a fall while playing and 30% reported falling more than once. Leading reasons for reported falls were lunging and moving backward. Participants who reported falling were significantly older (z = -2.60, p = 0.009) and slower on the pickleball T-test (z = -2.10, p = 0.036) than those who did not report falling. Hip abduction strength was not associated with fall history but was associated with faster time on the pickleball T-test (left rs = -.41, p < 0.001, right rs = -.48, p < 0.001). Single leg squat form and dorsiflexion were not related to fall history. Conclusion: Falls are common among recreational pickleball players, particularly older players. Fall prevention programs for pickleball players should be considered including multi-directional lunging, lower extremity strength and power development, and change of direction training that includes moving backward. Level of evidence: 2 [ABSTRACT FROM AUTHOR]

Background: Bilateral hip arthroscopic surgery for the treatment of femoroacetabular impingement (FAI) has demonstrated good outcomes at short-term follow-up, with significant improvements in pain, hip function, and patient-reported outcomes, coupled with a complication rate similar to that of unilateral surgery. Purpose: To investigate whether, in patients with bilateral symptomatic FAI, simultaneous bilateral hip arthroscopic surgery is an efficacious option that produces effective midterm outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: A prospective database of patients who underwent primary hip arthroscopic surgery between August 2012 and October 2020 was used to collect clinical data on 2 groups. Group 1 consisted of patients who underwent simultaneous bilateral hip arthroscopic surgery for the treatment of FAI. Group 2 represented a matched-pair control group of patients selected based on sex and age with signs and symptoms of unilateral FAI and in whom a single side was evaluated and treated. Differences in the International Hip Outcome Tool–12 and Non-Arthritic Hip Score scores were evaluated up to 5 years postoperatively. Results: In total, 171 patients (235 hips) were included, of whom 64 underwent simultaneous bilateral hip arthroscopic surgery (128 hips) and a control group of 107 patients (107 hips) underwent unilateral hip arthroscopic surgery. No significant differences were observed in International Hip Outcome Tool–12 scores between the 2 groups at 6 weeks, 3 months, 1 year, 2 years, and 5 years postoperatively. No significant differences were observed in Non–Arthritic Hip Score scores between the simultaneous bilateral and control groups at 6 weeks, 3 months, 6 months, 1 year, 2 years, and 5 years postoperatively. Overall, 18% of hips in the simultaneous bilateral group reported lateral femoral cutaneous nerve palsy at 2-week follow-up in comparison to 16% of hips in the control group. Conclusion: Simultaneous bilateral hip arthroscopic surgery for the treatment of FAI represents a safe treatment option, producing effective midterm outcomes in appropriately selected patients. [ABSTRACT FROM AUTHOR]

Background: Non-specific lower back pain (NSLBP) is prevalent among female police officers, influenced by genetic factors, aging, and occupational risks such as heavy lifting. This study evaluates a 6-week program combining core strengthening and hip mobility exercises to alleviate NSLBP. Objective: To assess the effectiveness of core strengthening and dynamic hip mobility exercises in reducing NSLBP among female officers. Methods and Material: The study involved 40 female officers aged 25-55 with NSLBP lasting at least 6 weeks using simple random sampling technique. Participants were randomly assigned to Group A (control) or Group B (experimental). Group B underwent a 6-week core strengthening and hip mobility exercise regimen, with pain intensity (NPRS) and low back disability (ODI) measured before and after. Results: Group B exhibited significantly lower pain intensity (3.5 ± 1.147 vs 7.3 ± 0.9234) and reduced low back disability (13.6 ± 2.909 vs 28.65 ± 2.207) compared to Group A. Conclusions: The study revealed that among female officers with NSLBP, core strengthening and hip mobility exercises proved more effective than traditional exercises in alleviating pain and reducing low back instability [ABSTRACT FROM AUTHOR]

Purpose: The primary aim was to assess whether a total hip arthroplasty (THA) was able to restore health-related quality of life (HRQoL) following an intracapsular hip fracture. The secondary aims were to assess changes in hip-specific function, fitness/frailty, mortality risk, complications and revision risk, and factors independently associated with these. Methods: This retrospective cohort study included all patients aged ≥ 50 years admitted with a hip fracture from the emergency department at a single centre during a 42-month period. Patient demographics, perioperative variables, complications, revision, and mortality were collected. Patient-reported outcome measures (PROMs) were assessed at final follow-up. Results: Among 250 identified patients, 189 (75.6%) were women with a mean age of 70.3 (range 50–94 years). Mean follow-up was 2.3 (SD 1.1) years. The implant and patient survival rates at 2 years were both 95.5% (95% confidence intervals (CI) +/− 2.7). Older age (hazard ratio [HR] 1.22, 95% CI 1.12–1.33, p < 0.001) and male sex (HR 3.33, 95% CI 1.15–10.0, p = 0.026) were independently associated with mortality. There were 19 (7.6%) postoperative complications that included 6 (2.4%) periprosthetic fractures, 5 (2.0%) deep infections, and 8 (3.2%) dislocations, of which 13 underwent revision. Increasing time to theatre (HR 1.02, 95% CI 1.01–1.03, p = 0.017) was independently associated with a postoperative complication. Postoperative PROMs were available for 166 (66.4%) patients. There were significant (p < 0.001) deteriorations in EuroQol-5D (Mean difference [MD] 0.192, 95% CI 0.133–0.252), Oxford hip score (MD 2.5, 95% CI 1.5–3.6), and fitness (Rockwood score MD 0.7, 95% CI 0.5–0.8) relative to preoperative levels of function. Conclusion: THA may be the treatment of choice in a physically active patient with the aim of restoring their HRQoL, hip function, and fitness, but this was not observed. Furthermore, there was a high complication rate which was associated with increasing time to theatre. Level of evidence: III, retrospective cohort study. [ABSTRACT FROM AUTHOR]

Purpose: Acetabular reconstruction in situ after extensive pelvic resection is technically challenging. The aim of this study was to investigate the feasibility of positioning guiders for acetabular reconstruction following pelvic tumor resection and the clinical benefit brought by the approach. Methods: The study included patients who underwent acetabular reconstruction following periacetabular tumor resection using a modular hemipelvic prosthesis. In the guider-assisted group (n = 14), guiders were designed and applied to assist acetabular reconstruction. In the traditional operation group (n = 18), the patients underwent the same surgery but without the guiders. The displacement of the hip rotation center before and after surgery was calculated. The complications and the Musculoskeletal Tumor Society—93 scores were documented. Results: The overall displacement of the hip rotation center was significantly reduced in the guider-assisted group compared with the traditional operation group (13.83 ± 4.06 vs. 22.95 ± 9.18 mm in P = 0.000, 95%CI 3.90–12.96), especially in the anteroposterior axis (3.77 ± 3.03 versus 13.51 ± 9.43 mm in P = 0.000, 95%CI 3.45–13.09). Guider-assisted acetabular reconstruction reduced the risk of prosthesis dislocation compared with the traditional operation (dislocation risks: 1/14, 7.1% vs. 4/18, 22.2%). Conclusion: Positioning guiders can effectively and conveniently help place the modular hemipelvic prosthesis at the native position, which might potentially reduce the risk of prosthesis dislocation. Level of evidence: Therapeutic level III. [ABSTRACT FROM AUTHOR]

This study investigated the effects of plyometric training on lower‐limb muscle strength and knee biomechanical characteristics during the landing phase. Twenty‐four male subjects were recruited for this study with a randomised controlled design. They were randomly divided into a plyometric training group and a traditional training group and underwent training for 16 weeks. Each subject was evaluated every 8 weeks for knee and hip isokinetic muscle strength as well as knee kinematics and kinetics during landing. The results indicated significant group and time interaction effects for knee extension strength (F = 74.942 and p = 0.001), hip extension strength (F = 99.763 and p = 0.000) and hip flexion strength (F = 182.922 and p = 0.000). For landing kinematics, there were significant group main effects for knee flexion angle range (F = 4.429 and p = 0.047), significant time main effects for valgus angle (F = 6.502 and p = 0.011) and significant group and time interaction effects for internal rotation angle range (F = 5.475 and p = 0.008). The group main effect for maximum knee flexion angle was significant (F = 7.534 and p = 0.012), and the group and time interaction effect for maximum internal rotation angle was significant (F = 15.737 and p = 0.001). For landing kinetics, the group main effect of the loading rate was significant (F = 4.576 and p = 0.044). Significant group and time interaction effects were observed for knee extension moment at the moment of maximum vertical ground reaction force (F = 5.095 and p = 0.010) and for abduction moment (F = 8.250 and p = 0.001). These findings suggest that plyometric training leads to greater improvements in hip and knee muscle strength and beneficial changes in knee biomechanics during landing compared to traditional training. Highlights: Plyometric training changes landing biomechanics.Changes help to reduce the risk of ACL injury.Changes from long‐term training are more noticeable. [ABSTRACT FROM AUTHOR]

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BACKGROUND: There are some rules that furniture designers must take into consideration to design ergonomic furniture. The main design principle is the target group for which the furniture will be designed, considering the dimensions of people who use the furniture. OBJECTIVE: The paper presents the correlation between 12 parts of children's body, as well as the proportion between stature and 11 other parts of the body which are used for the purposes of furniture and interior designers. METHODS: Field measurements include: Stature (S), Sitting height (She), Shoulder height (Sh), Popliteal height (Ph), Hip width (Hb), Elbow rest height (Erh), Buttock-popliteal length (Bpl), Buttock-knee length (Bkl), Thigh clearance (Tc), Eye height sitting (Eh), Knee height (Kh) and Shoulder breadth (Sb) to pupils aged 6–11 (grades 1 to 5). The measurements were done in 687 children in 12 primary schools in 4 different regions in Kosovo. RESULTS: The data of the study shows that, in general, there is a correlation (in some parts strong and in some medium) for the measured parts. Also, the study presents the proportion between the stature and other parts of the body which are necessary for the design of children's furniture. CONCLUSION: Using this data will enable furniture designers to easily target the dimensions of the group they will design, even by measuring only one dimension, i.e. stature and then setting the proportions for each piece separately. [ABSTRACT FROM AUTHOR]

Background: While several clinical factors have independently been linked to anterior cruciate ligament (ACL) injury risk factors, their collective impact on knee loading during the sidestep maneuver is unknown. To better understand these factors, we assessed the relationship between strength, balance, and sprint kinetics and external knee abduction moments during sidestepping on each leg. Methods: Sixteen male academy-level rugby union athletes (age, 20 ± 3 years; body-height, 186 ± 9 cm; body-mass, 99 ± 14 kg) were bilaterally assessed in single-leg: isokinetic concentric and eccentric knee and concentric hip strength, balance at 2 difficulty levels, vertical and horizontal force production during maximal sprinting, and 3-dimensional motion capture while sidestepping on the preferred and non-preferred leg. A hierarchical multiple regression analysis based on this theoretical approach of the mechanics of ACL injury risk was performed. Results: When sidestepping on the preferred leg, larger abduction moments were explained by less concentric hip extension strength and vertical force production during maximal sprinting (R 2 = 41%; ES = 0.64); when sidestepping on the non-preferred leg, larger abduction moments were explained by more concentric hip flexion strength (R 2 = 8%; ES = 0.29). Larger symmetry scores between the legs (representing greater abduction moments) were explained by more horizontal force production during maximal sprinting and less eccentric knee flexion strength (R 2 = 32%; ES = 0.56). Conclusions: Independently, the preferred and non-preferred legs contribute to increased knee abduction moments via unique distributions of strength and/or sprint kinetics. The allocations of strength and sprint kinetics appear interrelated through weaker posterior muscular strength and may be modifiable through a targeted strength training approach. [ABSTRACT FROM AUTHOR]

Background: High tibial osteotomy (HTO) aims to realign the varus knee to alleviate stress in the medial compartment. However, detailed information on the impact of HTO on stress distribution across the tibiofemoral joint surface still needs to be completely elucidated. Purpose/Hypothesis: The present study aimed to analyze the subchondral bone density distribution to validate the alignment threshold causing paradoxical changes. We hypothesized that there would be a paradoxical stress change in the medial compartment beyond a specific threshold for lower limb realignment after HTO. Study Design: Case series; Level of evidence, 4. Methods: A retrospective clinical study of 32 knees from 30 patients who underwent medial opening-wedge HTO between 2015 and 2019 was conducted at Hokkaido University Hospital. The subchondral bone density across the tibiofemoral joint was analyzed using computed tomography–osteoabsorptiometry before and after HTO. The high-density area (HDA) within the medial and lateral compartments and their subregions, which were quartered in the coronal plane, was specifically examined. Results: The hip-knee-ankle angle, medial proximal tibial angle (MPTA), joint line obliquity (JLO), and joint line convergence angle significantly changed after HTO (P <.01). The HDA of the medial compartment to the total HDA ratio decreased from 83% to 77%. Paradoxically, the HDA in the most central subregion of the medial compartment increased from 24% to 30%. There were significant differences between MPTA and JLO in patients with and without paradoxical changes in the HDA. MPTA and JLO cutoff values causing paradoxical changes in the HDA were 94° and 4°, respectively. Conclusion: There was a paradoxical stress increase in the M4 region at the medial compartment associated with the MPTA and JLO beyond specific thresholds. Therefore, surgical planning should be cautiously performed to prevent overcorrection, which can lead to adverse stress distribution changes. [ABSTRACT FROM AUTHOR]

"Super-shoes" are designed to improve endurance running performance by reducing the metabolic demands of running. Although the research on "super-shoes" is still developing and has mostly been studied in male runners, it is not clear how possible mediating factors, such as foot strike pattern, influence the metabolic cost and joint mechanics in competitive female runners. Purpose: The objective of this study is to assess the influence of "super-shoes" on metabolic cost and joint mechanics in competitive female runners and to understand how foot strike patter may influence the footwear effects. Methods: Eighteen competitive female runners ran four 5-min bouts on a force instrumented treadmill at 12.9 km⋅h-1 in 1) Nike Vaporfly Next% 2™(SUPER) and 2) Nike Pegasus 38™(CON) in a randomized and mirrored order. Results: Metabolic power was improved by 4.2% (P < 0.001; d = 0.43) and metatarsophalangeal (MTP) negative work (P < 0.001; d = 1.22), ankle negative work (P = 0.001; d = 0.67), and ankle positive work (P < 0.001; d = 0.97) were all smaller when running in SUPER compared with CON. There was no correlation between foot strike pattern and the between-shoe (CON to SUPER) percentage change for metabolic power (r = 0.093, P = 0.715). Conclusions: Metabolic power improved by 4.2% in "super-shoes" (but only by ~3.2% if controlling for shoe mass differences) in this cohort of competitive female runners, which is a smaller improvement than previously observed in men. The reduced mechanical demand at the MTP and ankle in "super-shoes" are consistent with previous literature and may explain or contribute to the metabolic improvements observed in "super-shoes"; however, foot strike pattern was not a moderating factor for the metabolic improvements of "super-shoes." Future studies should directly compare the metabolic response among different types of "super-shoes" between men and women. [ABSTRACT FROM AUTHOR]

Purpose: The aim was to quantify jump performance in children with cerebral palsy (CP) and determine if the expected deficit is related to their lower body joint kinetics and kinematics. Methods: Twenty-four ambulatory (n = 17 level I and 7 level II in the Gross Motor Function Classification System) children with spastic CP (n = 13 unilateral and 11 bilateral) and 24 age-, sex-, and race matched typically developing controls were studied. Jump height and peak power and range of motion at the hip, knee, and ankle of the more affected limb in children with CP and the nondominant limb in controls were assessed during a countermovement jump using three-dimensional motion capture and a force platform. Results: Compared with controls, children with CP had lower jump height (33%, Cohen's d (d) = 1.217), peak power at the knee (39%, d = 1.013) and ankle (46%, d = 1.687), and range of motion at the hip (32%, d = 1.180), knee (39%, d = 2.067), and ankle (46%, d = 3.195; all P < 0.001). Jump height was positively related to hip, knee, and ankle power and range of motion in children with CP (rs range = 0.474-0.613, P < 0.05), and hip and ankle power and knee and ankle range of motion in controls (rs range = 0.458-0.630, P < 0.05). The group difference in jump height was no longer detected when ankle joint power, ankle range of motion, or knee range of motion was statistically controlled (P > 0.15). Conclusions: Jump performance is compromised in children with CP and is associated with low power generation and range of motion in the lower limb, especially at the ankle. [ABSTRACT FROM AUTHOR]

Background: The relationship between hip morphological changes and joint concentricity in infants with late-detected developmental dysplasia of the hip (DDH) treated with gradual reduction remains unclear. Therefore, we investigated hip morphological changes and concentricity in infants with late-detected unilateral DDH using magnetic resonance imaging (MRI) during gradual reduction. Methods: We enrolled 20 infants aged ≥ 12 months with unilateral DDH. Treatment comprised continuous traction, a hip-spica cast, and an abduction brace. MRI was performed before treatment, immediately after hip-spica cast placement, after cast removal, and at the end of the brace. We evaluated the acetabulum and femoral head morphology and joint concentricity. Results: The mean age was 25 months, and female sex and the left side were predominant. Before treatment, the acetabulum was small and shallow and the femoral head was spherically flat on the affected side. Immediately after the continuous traction, the affected acetabulum and femoral head were still smaller than the healthy/contralateral one. However, they improved to a deeper acetabulum and round femoral head. Intra-articular soft tissue (IAST) and femoral–acetabular distance (FAD) continuously decreased, indicating gradual improvement in joint concentricity. Deeper formation of the acetabulum and round shaping of the femoral head had occurred even in non-concentric reduction. Conclusion: The shape and concentricity of the hip joint improved after treatment; however, the acetabulum and femoral head remained small. The deeper acetabulum and round femoral head were observed the non-concentric reduction before the concentric reduction was achieved. The continuous decrease in IAST and FAD indicates effective post-traction therapy. [ABSTRACT FROM AUTHOR]

Warming up is considered effective in improving performance and preventing injury. Despite this, there have been few studies investigating warm-up programs in golf and whether specific factors contribute to improved performance. The purpose of this study was to examine the immediate effects of combined foam rolling and dynamic stretch (FR + DS) to the lead hip on golf swing performance, hip range of motion (ROM), and muscle strength in amateur golfers using a randomized crossover design. The study sample comprised 22 men (mean ± SD; age, 32.6 ± 8.5 years, body mass index (BMI), 23.4 ± 2.7 kg-m²). Subjects were assigned to receive either FR + DS or repetitive golf swing practice (SW) before crossing over to the other intervention for another day. Measurements included golf swing performance (ball speed, club head speed, flight distance ["carry"], spin rate, and launch angle), hip internal rotation (IR), and external rotation (ER) ROM, as well as hip IR and ER muscle strength. Comparisons between groups were made before and after each intervention. For golf swing performance, FR + DS improved "carry" significantly more than SW (p < 0.05). No significant differences in golf swing performance other than "carry" were found. In addition, IR ROM and IR muscle strength of the lead hip were significantly increased in the FR + DS group (p < 0.05). FR + DS has effects on improving lead hip IR ROM and IR muscle strength, which may facilitate golfers' swing and "carry." FR + DS shows promise as a warm-up method for amateur golfers who want to improve golf performance. [ABSTRACT FROM AUTHOR]