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Introduction: Unlike the most common training approaches for bodybuilding, powerlifting programs are generally based on maximum and submaximal loads, putting enormous stresses on the lumbar spine. The flexion relaxation phenomenon evaluation is a clinical tool used for low back pain (LBP) assessment. This study aimed to evaluate the role of the flexion relaxation phenomenon in the analysis of LBP in the powerlifters. Methods: Healthy professional powerlifters participated in the study. In fact, we divided the participants into a LBP-low-risk group and a LBP-high-risk group, based on a prior history of LBP. Outcome measures included flexion relaxation ratio (FRR) and trough surface electromyography collected during trunk maximum voluntary flexion; furthermore, during a bench press lifting, we measured the height of the arched back (ARCH), using a camera and the Kinovea video editing software, to consider a potential correlation with the risk of LBP. Results: We included a group of 18 male (aged 24–39 y) powerlifters of 93 kg category. We measured a nonsignificant mean difference of ARCH between low-risk LBP group and high-risk LBP subjects. Curiously, maximum voluntary flexions were both above the threshold of 3.2 μV; therefore, with an absence of appropriate myoelectric silence, on the contrary, the FRR ratios were higher than 9.5, considering the presence of the phenomenon, exclusively for the low-risk group. The lumbar arched back measurement data did not report any association with the LBP risk, regarding the maximum voluntary flexion value, and even more than the FRR there is a relationship with the presence or the absence of LBP risk. Conclusions: FRR could be considered as a useful parameter for studying the risk of LBP in powerlifting. The FRR index not only refers to the possible myoelectric silence of the lumbar muscles in trunk maximum forward flexion but also takes into account the energy value delivered by the lumbar muscles during the flexion. Furthermore, we can indicate that the size of the powerlifter ARCH may not be a determining factor in the occurrence of LBP. [ABSTRACT FROM AUTHOR]

Context: Decreased trunk neuromuscular control is a risk factor for both upper- and lower-extremity injuries, yet there are few reliable and valid clinical tests to identify deficits. Objective: The purpose of this study was to determine the reliability and known-groups validity of a novel clinical test, the seated trunk control test (STCT). Design: Cross-sectional reliability and known-groups validity study. Setting: Laboratory. Participants: 89 unique participants: 34 were 3 months postoperative anterior cruciate ligament reconstruction (ACLR) and 55 healthy controls. Methods: For the STCT, participants sat on a balance board with their eyes closed for three 30-second trials while investigators counted balance errors. Intraclass correlations (ICCs) were used to assess interrater reliability (N = 20) and test–retest reliability (N = 40). To assess known-groups validity, independent t tests were used to compare STCT errors at 3 months post-ACLR with healthy matched controls (N = 34/group). Area under a receiver operating characteristic curve identified an optimal cutoff for distinguishing between groups. Results: The STCT had perfect interrater reliability (ICC2,3 = 1.00) and good test–retest reliability (ICC3,3 =.79; 95% confidence interval =.61–.89). The ACLR group made significantly more errors on the STCT (mean [SD] = 15.5 [5.4]) than controls (mean [SD] = 8.2 [4.1]; P <.001, Cohen d = 1.52). The STCT's ability to distinguish between groups was excellent (area under a ROC curve = 0.86). A cutoff of 12 errors maximized sensitivity (76%) and specificity (85%). Conclusions: The STCT is reliable between raters and across days. It also has excellent ability to distinguish between individuals with a recent ACLR and healthy matched controls, which provides initial evidence to suggest that the STCT may be clinically useful for identifying deficits in trunk neuromuscular control. [ABSTRACT FROM AUTHOR]

Background: Balance while seated and the capacity to conduct selective trunk movements are significant predictors of functional outcomes following stroke. Patients with inappropriate muscle activation and inadequate movement control in the trunk muscles cause mobility and daily function difficulties. Stroke patients have weak leg muscles and decreased balance, resulting in compensatory changes. Functional postural strategy training is necessary to restore balance in these patients. Few studies have examined the effect of physical therapy trunk exercises with hip strategy training on improving balance and increasing independence after stroke. Purpose: This study aimed to explore the effect of selective trunk exercises (STE) with hip strategy training in improving balance in patients with stroke as well as independence levels. Method: A multicenter inpatient stroke treatment randomized pre‐ and post‐test control trial. Forty‐six stroke survivors were randomly allocated to experimental or control groups (n = 23 each). The experimental group received hip strategy training and trunk exercises. All groups received Neuro‐Developmental Treatment (NDT)‐based physical therapy four times a week for 6 weeks. Trunk impairment scale, Berg Balance Scale (BBS), and functional independence measure (FIM) measured static and dynamic seated balance, functional balance, and trunk movement coordination pre‐ and post‐therapy. Results: The experimental group's post‐therapeutic measures were substantially higher than the control group. The experimental group's TIS score, and subscale improved more than the control group. The experimental group considerably increased the BBS score. The experimental group also showed greater FIM gains. Conclusions: This study demonstrated that adding STE in conjunction with hip strategy training to patients after has a positive impact on trunk control while maintaining static and dynamic sitting balance, functional balance, and independence levels which are effective in stroke rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: Activity-based locomotor training improves intrinsic trunk control in children with spinal cord injury (SCI). To reinforce these improvements, there is a need to develop community integration activities to allow a patient to apply the retrained nervous system at home. One activity that has been explored is rocking in a rocking chair. This paper describes the design, fabrication, and evaluation of a rocking chair for children with SCI. Materials and Methods: The Quality Function Deployment (QFD) design process was used. Fundamental needs and features for the rocking chair were defined in a focus group with experienced therapists, and needs were then rated for importance. A House of Quality (HOQ) matrix was developed to correlate needs with design features, and a prototype design was generated. Virtual motion studies and finite element analysis (FEA) were utilized to assess the design. The chair was fabricated and physical testing was performed, including tipping and static and dynamic load assessments. Results and Conclusions: The needs identified through the QFD process were categorized into (1) safety, (2) therapeutic, (3) practical and aesthetic, and (4) data to track chair use. Features selected to meet these needs include safety stops, padding, straps, a stable base, armrests, adjustable footrest, and sensors to capture rocking data. FEA showed a factor of safety (FOS) > 5. Physical testing confirmed physical integrity, load-bearing capacity, and stability of the prototype glider rocking chair. The prototype provides a safe tool for further investigation of rocking for promotion of trunk muscle activation in children with SCI. IMPLICATIONS FOR REHABILITATION: Rocking in a rocking chair promotes carryover of gained trunk control capacity, from clinic to home in a population that is non-ambulatory. Rocking provides opportunity for self-practice in population with severely compromised capacity. Rocking is a movement that may be performed when other types of movement cannot be readily performed, e.g., resistance exercise, movement against gravity. Rocking creates opportunity for repetitive, voluntary, self-directed movement that is inherently pleasurable and reinforcing. [ABSTRACT FROM AUTHOR]

Objective: One of the main features of polycystic ovary syndrome (PCOS) is increased adipose tissue, which can result in hormonal disturbances. In the present study, we aimed to investigate which indicator of obesity could better associate with hormonal disturbances in PCOS women. Methods: In this cross-sectional analysis, women with PCOS were included according to the Rotterdam criteria. Fasting blood samples were analyzed for biochemical, metabolic, and hormonal parameters. Anthropometric measures comprised body composition indices (assessed by bioelectric impedance analysis [BIA]), waist circumference, body mass index (BMI), and waist-to-height ratio (WHtR). Linear regression modeling was used to assess the association between anthropometric indices and hormonal imbalance, adjusted for age, mensuration status, and the homeostasis model assessment-estimated insulin resistance (HOMA-IR). Receiver operating characteristics (ROC) curves were utilized to ascertain the sensitivity, specificity, and optimal cut-off points of various anthropometric indices in identifying hyperandrogenism. Results: A total of 129 PCOS women with a median (interquartile range [IQR]) age of 32.0 (23.0–32.0) years and a median BMI of 26.3 (23.00-29.70) kg/m2 were enrolled. In the adjusted linear regression model, BMI (β = 0.053, P < 0.001), waist circumference (β = 0.021, P = 0.001), WHtR (β = 3.325, P = 0.002), total fat mass (β = 0.021, P = 0.002), trunk fat mass (β = 0.038, P = 0.006), and leg fat mass (β = 0.045, P = 0.004) were positively associated with free androgen index (FAI). In addition, BMI (β=−0.017, P = 0.003), waist circumference (β=−0.008, P = 0.002), WHtR (β=−1.167, P = 0.004), total fat mass (β=−0.008, P=0.003), trunk fat mass (β=−0.017, P=0.001), and leg fat mass (β=−0.018, P=0.004) were negatively associated with the serum level of sex hormone binding globulin (SHBG). WHtR showed the greatest area under the curve (AUC) value (AUC = 0.676, P = 0.001) for identifying hyperandrogenism (FAI ≥ 4.97 or total testosterone ≥ 0.7 ng/mL) in PCOS women with corresponding sensitivity of 87.30% and specificity of 39.70%. Conclusions: WHtR is related to hyperandrogenism in PCOS better than other anthropometric measures. [ABSTRACT FROM AUTHOR]

This study compared lower extremity, trunk, and upper extremity kinematics between tee and front toss hitting in youth baseball athletes. Twenty youth baseball athletes (14.3±2.9 yrs) performed three maximal effort swings off front toss and tee. Kinematic data were collected during the preparatory and acceleration phases. Lower extremity, trunk, and upper extremity kinematics were compared between tee and front toss hitting using 1-dimensional statistical parametric mapping (SPM). There was a significant difference in trunk kinematics between tee and front toss during the preparatory phase (p=.001); the trunk rotated more toward the back side when hitting off a tee compared to front toss (p<0.001). There was also a significant difference in trunk kinematics between tee and front toss for 67% of the acceleration phase; the trunk rotated more towards the back side from 0 to 67% when hitting off the tee (p<0.001). Significant differences were found in trunk kinematics between tee and front toss hitting in youth baseball players, where the trunk is less rotated toward the pitcher in the tee than in the front toss. Coaches utilize various training modalities to enhance hitting performance; however, differences in trunk kinematics should be considered between modalities when developing fundamental hitting techiques in youth baseball athletes. [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]

Background: Changes in the trunk and lower limbs' sagittal movements may cause patellofemoral pain (PFP) because they influence the forces acting on this joint. Objectives: To compare trunk and lower limb sagittal kinematics between women with and without PFP during functional tests and to verify whether sagittal trunk kinematics are correlated with those of the knees and ankles. Methods: A total of 30 women with PFP and 30 asymptomatic women performed single-leg squat (SLS) and step-down (SD) tests and were filmed by a camera in the sagittal plane. The trunk inclination angle, forward knee displacement, and ankle angle were calculated. Results: The PFP group exhibited less trunk flexion (SLS, p =.006; SD, p =.016) and greater forward knee displacement (SLS, p =.001; SD, p =.004) than the asymptomatic group; there was no significant difference in ankle angle (SLS, p =.074; SD, p =.278). Correlation analysis revealed that decreased trunk flexion was associated with increased forward knee displacement (SLS, r = −0.439, p =.000; SD, r = −0.365, p =.004) and ankle dorsiflexion (SLS, r = −0.339, p =.008; SD, r = −0.356, p =.005). Conclusion: Women with PFP present kinematic alterations of the trunk and knee in the sagittal plane during unipodal activities. Furthermore, the trunk and lower limb sagittal movements were interdependent. [ABSTRACT FROM AUTHOR]

The purpose of this study was to clarify the relationship between the efficiency of mechanical energy flow in the torso and bat head speed at impact. Ninety-eight amateur baseball players batted a light ball tossed from the pitcher direction 3.2 m away. The batting motion and ground reaction forces acting on each foot were recorded using a motion capture system and two force plates, respectively. The mechanical powers of the joint forces and joint torques were calculated to measure the generation, absorption, and transfer of mechanical energy in the torso. The transfer efficiency of mechanical energy in the torso was defined as the ratio of the mechanical energy inflow into the thorax from the torso joint to the mechanical energy outflow from the pelvis to the torso joint. The correlation coefficient between the bat head speed and transfer efficiency of mechanical energy in the torso was very low. Conversely, the mechanical energy flow in the torso was significantly correlated to the bat head speed. Therefore, the results suggest that the torso in baseball batting is not utilised for the generation of mechanical energy but acts as a pathway for the transfer of mechanical energy. [ABSTRACT FROM AUTHOR]

Purpose: To compare the trunk biomechanical characteristics between the sit-to-stand and stand-to-sit performed at self-selected and fast speeds in stroke survivors and healthy-matched controls. Methods: Thirty individuals (15 stroke survivors and 15 healthy-matched controls) were included. The following biomechanical characteristics were determined: peak of trunk forward flexion and time until the peak of trunk forward flexion, total duration, phase I (sit-to-stand: time spent from the beginning to seat-off; stand-to-sit: time spent from the beginning to seat-on) and II durations (sit-to-stand: time spent from seat-off to the end of the task; stand-to-sit: time spent from the seat-on to the end of the task). Two-way repeated measures ANOVA was used (α = 5%). Results: The maximum angle of trunk forward flexion and time spent until the maximum angle of trunk forward flexion in both tasks were significantly higher in stroke survivors. For both groups and speeds, phase I duration and peak of trunk forward flexion of the stand-to-sit were significantly higher than that of the sit-to-stand (11.41≤F ≤ 33.60; 0.001 ≤ p ≤ 0.002) and, phase II duration was significantly higher during the sit-to-stand than that of the stand-to-sit (21.27 ≤ F ≤ 65.10; p ≤ 0.001). Conclusions: These results confirm specific trunk biomechanical characteristics between sit-to-stand and stand-to-sit in stroke survivors and healthy-matched controls. IMPLICATIONS FOR REHABILITATION: Specific biomechanical characteristics between the sit-to-stand and stand-to-sit were confirmed in stroke survivors and healthy-matched controls at both speeds. Fast speeds showed differences that were not observed at self-selected speeds. Trunk biomechanical characteristics must be carefully evaluated and should be considered in rehabilitation programs that aim to improve sit-to-stand and stand-to-sit performance. [ABSTRACT FROM AUTHOR]

Methods of modelling the female torso during physical activity often neglect the position and movement of the breast. This novel investigation compares three female torso modelling approaches that differ in complexity (integrated breast, fixed breast, dynamic breast) to determine the effect on spinal joint moments during running and jumping. The commonly used integrated breast model distributed breast mass within the torso, the fixed breast model attached the mass of the breasts to fixed positions on the anterior of the torso, and a new dynamic breast model enabled relative motion between the breasts and anterior torso. Key findings demonstrated minimal differences in lumbar spine moments (<0.05 Nm/kg; 4%) between integrated breast and fixed breast models but greater differences, up to 0.86 Nm/kg (68%) during running and 0.89 Nm/kg (82%) during jumping, when breast motion was included. Thoracic spine moments revealed similar patterns with minimal differences (<0.05 Nm/kg; 11%) between integrated breast and fixed breast models and greater differences, up to 0.48 Nm/kg (92%) during running and 0.63 Nm/kg (66%) during jumping, with the dynamic breast model. Future female musculoskeletal models should consider including breast mass and motion to avoid mis-representing spinal loading in females during running and jumping. [ABSTRACT FROM AUTHOR]

The functional importance of trunk muscle strength for running movement is widely recognised, but the kinematic effects of undertaking specific training are unclear. This study investigated the change in joint angle and its variability during running following trunk muscle training. Eighteen young female and novice runners participated. Using Plug-in-gait model with infrared markers attached to the body surface, the lower limb and lumber angles during running were measured, and the variability was examined by calculating the coefficient variation and Lyapunov exponent. Measurements of trunk endurance were also performed. Over four weeks of training, the subjects performed trunk muscle endurance trainings three times a week. Following this intervention, trunk endurance was found to have significantly increased. The Lyapunov exponent of lumbar flexion-extension angle also significantly increased. Moreover, a decreased range of the ankle angle and increased range of the hip angle were observed following the training. These results demonstrate that the trunk training promoted adjustments to lumbar movement and altered the movement patterns of the participants' lower limbs during running. [ABSTRACT FROM AUTHOR]

BACKGROUND: Evidence-based guidelines are needed to inform rehabilitation practice including the effect of non-paralytic lower limb resistance exercise with abdominal drawing-in technique (ADIM) on recovery of trunk control, balance and daily living after stroke survivors. OBJECTIVE: The purpose of this study was to compare the effects of trunk control strengthening performed in non-paralytic lower limb resistance exercise with ADIM on trunk control, balance, daily living in stroke survivors. METHODS: The 24 participants with stroke were randomly divided into three groups: lower limb resistance exercise group (LRAG; n = 8), lower limb exercise group (LAG; n = 8), and control group (CG; n = 8). The training sessions were conducted three times a week for four weeks. Outcome measures included the Korean version Trunk Impairment Scale (K-TIS), Postural Assessment Scale of Stroke (PASS), Modified Functional Reach Test (mFRT), Berg Balance Scale (BBS), Foot print and Modified Barthel's Index (MBI). RESULTS: The results showed that the LRAG had a significant effect on the K-TIS, PASS, mFRT, Foot print and MBI than the LAG and CG (p < 0.05). The BBS results showed a significant difference the CG (p < 0.05). CONCLUSION: This study showed that repeated non-paralytic lower limb resistance exercises with ADIM can be used clinically as a training method for general physiotherapy in patients with reduced postural control, balance and daily living. [ABSTRACT FROM AUTHOR]

The current study explored the relationships between countermovement jump (CMJ) profiles and baseball pitching performance. Nineteen Division I collegiate pitchers performed in-laboratory pitching and bilateral CMJs. Whole-body kinematics and ground reaction force were collected during both pitching and CMJ evaluations. Statistically significant correlations of concentric impulse and peak power in the CMJ test with fastball velocity were observed (r = 0.71 and 0.68). Concentric impulse in CMJ also showed a statistically significant correlation with linear momentum in the anterior-posterior direction during pitching (r = 0.68). Lean body mass and body mass showed statistically significant correlations with both of the 2 linear momentums during pitching (r = 0.71~0.83), and concentric impulse in CMJ (r = 0.71 and 0.81). Pelvis and trunk pitching mechanics did not correlate with any of the CMJ variables at the statistically significant level, whereas the direction of the correlations varied (Irl < 0.45). Assessment of a baseball pitcher's CMJ should focus on concentric impulse and peak power because only these showed meaningful relationships with fastball velocity or momentum generation during pitching. An increase in lean body mass is also suggested to be able to generate more impulse and momentum. Baseball coaches, strength coaches, and clinicians are encouraged to include lower-body explosive training to enhance the force and power output capacity of baseball pitchers. [ABSTRACT FROM AUTHOR]

BACKGROUND: Weakness and atrophy in trunk muscles have been associated with chronic low back pain (CLBP). OBJECTIVE: This study aimed to identify isometric exercises resulting the highest trunk muscle activity for individuals with and without CLBP. METHODS: Fourteen males with CLBP and 15 healthy age-matched healthy subjects were recruited for this study. Muscle activity during maximal voluntary isometric contraction (MVIC) was measured for a comparative reference with surface electromyography (sEMG) from six trunk muscles. Thereafter maximum EMG amplitude values were measured during eleven trunk stability exercises. The maximal EMG activity in each exercise relative to the MVICs was analyzed using generalizing estimating equations (GEE) models with the unstructured correlation structure. RESULTS: The GEE models showed statistically significant differences in muscle activity between exercises within both groups (p < 0.001), with no significant differences between groups (p > 0.05). The highest muscle activity was achieved with the hip flexion machine for multifidus, side pull with a resistance band for lumbar extensors, side and single-arm cable pull exercises for thoracic extensors, rotary plank and the hip flexion machine for abdominal. CONCLUSION: This study found five isometric trunk exercises that exhibited highest muscle activity depending on muscle tested, with no significant difference between individuals with and without CLBP. [ABSTRACT FROM AUTHOR]

BACKGROUND: Step width during walking can provide important information about aging and pathology. Although knee osteoarthritis (OA) is a common disease in elderly women, little is known about how different step widths influence gait parameters in patients with knee OA. OBJECTIVE: To address this, we investigated the differences between narrower and wider step width on the center of mass (CoM) and gait biomechanics of elderly women with knee OA. METHODS: Gait and CoM data were measured using a three-dimensional motion capture system and anthropometric data were acquired via standing full-limb radiography. Thirty elderly women with knee OA were divided into two groups depending on the average step width value (0.16 m). Specifically, the narrower step width group included those with a below average step width (n = 15) and the wider step width group included those with an above average step width (n = 15). The differences between the two groups were analyzed using an independent t -test. RESULTS: Walking speed, step length, knee and ankle sagittal excursion, and medial-lateral CoM range were significantly greater in the narrower group. In contrast, the medial-lateral CoM velocity, medial-lateral ground reaction force (GRF), and foot progression angle were significantly higher in wider group. The external knee adduction moment, vertical GRF, and vertical CoM did not differ between the groups. CONCLUSIONS: Our data indicate that step width in women with knee OA is associated with trunk motion and gait patterns. People with a narrower step might improve their gait function by increasing trunk frontal control to maintain gait stability. In contrast, in those with a wider step, greater toe out angle and shorter step length might be a compensatory adaptation to reduce knee loading. [ABSTRACT FROM AUTHOR]

Athletes with a history of concussion are at a greater risk for lower extremity musculoskeletal injury. Female athletes may be at an even greater risk than male athletes. Previous researchers on postconcussion landing biomechanics have focused on the lower extremities, but the trunk plays a crucial role as an injury risk factor. To compare lower extremity and trunk biomechanics during jump-landing and cutting maneuvers between female athletes with and those without a concussion history. Cross-sectional study. Biomechanics laboratory. A total of 26 athletes (mean ± SD age = 19.0 ± 1.3 years, height = 1.68 ± 0.07 m, mass = 64.02 ± 6.76 kg, body mass index = 22.58 ± 1.97 kg/m2; median [interquartile range] time since most recent concussion = 37.5 months [25.0 months, 65.8 months]) with a concussion history and 38 athletes (age = 19.0 ± 1.1 years, height = 1.71 ± 0.08 m, mass = 64.72 ± 9.45 kg, body mass index = 22.14 ± 1.80 kg/m2) without a concussion history. Peak kinetics (vertical ground reaction force, vertical loading rate, external knee-abduction moment, and external knee-flexion moment) and kinematics (trunk-flexion angle, trunk lateral-bending angle, ankle-dorsiflexion angle, knee-flexion angle, knee-abduction angle, and hip-flexion angle) were obtained during the eccentric portion of jump-landing and cutting tasks. Separate 2 (group) × 2 (limb) between- and within-factors analyses of covariance were used to compare outcomes between groups. We covaried for time since the most recent concussion and the limb that had a history of musculoskeletal injury. Athletes with a concussion history displayed a greater peak knee-abduction angle in their nondominant limb than their dominant limb (P =.01, ηp2 = 0.107) and the nondominant limb of athletes without a concussion history (P =.02, ηp2 = 0.083) during jump landing. They also had less trunk lateral bending during cutting compared with athletes without a concussion history (P =.005, ηp2 = 0.126). Our results indicated landing biomechanics are different between female athletes with and those without a concussion history. This finding may be due to impairments in neuromuscular control postconcussion that may ultimately increase the risk of subsequent lower extremity injury, although further research is warranted given the cross-sectional nature of our study. [ABSTRACT FROM AUTHOR]

High-level golfers use various warm-up strategies to enhance clubhead and ball speed, including weighted equipment. We investigated the acute effects of the SuperSpeed Golf™ weighted-club warm-up on clubhead, ball, and swing kinematics, and the persistence of any acute effects in subsequent sets. Twelve competitive golfers (handicap < 3.0) completed five sets of five swings using their own drivers under two randomised warm-up conditions (Control and SuperSpeed). We compared swing, peak segment and club angular velocity, and centre of mass (COM) parameters collected using a 3D motion capture system (500 Hz) between conditions. The temporal persistence of any meaningful (Cohen's d ≥ small) and significant (p≤ 0.05) effect detected in the first set was investigated in subsequent sets. SuperSpeed led to small significant changes in clubhead speed (2.6 mph); downswing time; peak angular velocities of the torso, lead arm, and club; and two COM variables in the initial set. There was no significant change in ball speed, resulting in a large negative change in smash factor acutely (d − 0.82, p= 0.009). Nearly all changes observed were no longer meaningful or significant in subsequent sets. Overall, golfers can expect an increase in driving clubhead speed on the first tee using the SuperSpeed Golf™ vs Control warm-up, with trivial effects from the second tee onwards. [ABSTRACT FROM AUTHOR]

Individuals with autism spectrum disorder (ASD) engage in less physical activity than typically-developing peers. This can result in serious negative consequences for individual well-being and may contribute to the physical, behavioral, and emotional challenges associated with ASD. This study explored the potential benefits of trainer-led, individualized, physical fitness sessions specialized for ASD. Eleven individuals (ages 7–24 years) with ASD were assessed at baseline and following 15 fitness sessions. Participants demonstrated improvements in core and lower-body strength and reductions in restricted and repetitive patterns of behavior, along with non-significant but marked reductions in issues with daytime sleepiness. Results suggest the merit of specialized fitness programs and emphasize the need for larger and more rigorous research studies on this topic. [ABSTRACT FROM AUTHOR]

Trunk control is associated with gross motor development. This study examines the relationship between segmental trunk control and gross motor performance in low birth weight (LBW) infants A total of 42 LBW infants and 43 normal birth weight (NBW) infants aged 3–9 months were sampled for this cross-sectional study. All infants were evaluated one time by the Segmental Assessment Trunk Control (SATCo) and the Alberta Infant Motor Scale (AIMS) Statistically high and significant correlations were found between gross motor performance and segmental trunk control in all sample populations (r = 0.835; p =.001). No statistically significant difference was found regarding the segmental trunk control between the groups (p =.119). The LBW infants with atypical motor development had poorer trunk control than the LBW infants with typical development (f = 5.480; p =.001). Our results show that LBW infants with atypical motor development had poorer trunk control than LBW infants with typical motor development. It was found that the segmental trunk controls of LBW infants were 0.398 times lower than in NBW infants. [ABSTRACT FROM AUTHOR]

Context: Elite golfers have a high incidence of low back pain. Recent reviews have emphasized the need for investigation into how to prevent low back pain in golfers, prompting the current study. Design: Prospective longitudinal cohort study. Methods: Forty-one injury-free golfers were included in this study. At baseline, lower quadrant joint angles and club and ball performance were measured while each golfer performed 10 drives. The golfers were then monitored for 6 months and were allocated into 2 groups depending on whether or not they developed low back pain. The initial, baseline kinematic variables of the low back pain group and the uninjured group were then compared. Results: Over the 6-month monitoring period, 17 (41%) of the golfers developed low back pain. At baseline assessment, the low back pain group had 4° less lead ankle dorsiflexion at setup (P = .01; effect size = 0.82), 6° less lead knee flexion at the top of the backswing (P = .05; effect size = 0.64), 6° less lead ankle dorsiflexion at the top of the backswing (P = .01; effect size = 0.82), 6° more trail hip adduction at the top of the backswing (P = .02; effect size = 0.79), 9° more trail knee flexion at impact (P = .05; effect size = -0.64), and 6° more trail hip adduction at the end of follow through (P < .00; effect size = 1.00). Conclusion: Golfers who developed low back pain during the 6-month monitoring period displayed distinct differences in biomechanics at baseline when all golfers were injury free. These biomechanical differences may be considered a precursor to injury. Three-dimensional motion analysis may indicate whether elite golfers are at risk of developing low back pain. Research is needed to assess whether targeted exercise and sports drills aimed at addressing the biomechanical risk factors identified may prevent low back pain in elite golfers. [ABSTRACT FROM AUTHOR]

Objectives: Oscillatory exercises using flexible poles, such as the Flexi-bar, were recommended as rehabilitation programs to increase trunk muscles strength; however, the strategy to enhance the training effects is under investigations. The aim of this study was to characterize the trunk movements and muscle activation patterns when performing an oscillation exercise with flexible poles in different weights. Methods: Twelve healthy male participants performed oscillation exercises with flexible poles of different weights. The center of mass, as well as surface electromyography for 10 trunk muscles were assessed while participants performed oscillation exercises. Results: The participants' trunks showed rhythmic anterior-posterior movement during oscillation exercises using flexible poles. The center-of-mass movement distances were 20.32 (6.73) mm, 25.33 (5.31) mm, 32.40 (9.94) mm, and 37.28 (21.59) mm for the Flexi-bar, light pole, medium pole, and heavy pole, respectively. Erector spinae, internal obliques, multifidus, and external obliques revealed significant activation levels during oscillation exercises. The participants who could perform steady and smooth oscillation with heavy pole for 30 seconds revealed phasic sequential muscle activation. Conclusion: The present study suggested that oscillation exercises with flexible poles were associated with a concomitant trunk movement in anterior-posterior direction and an effective activation of trunk muscles. [ABSTRACT FROM AUTHOR]

The purpose was to assess the intra-trunk and arm coordination of Olympic athletes during rowing on an ergometer. Rowing was performed at three stroke rates (18, 26, and 32 strokes/min). The sagittal plane motions of trunk segments and upper arm were collected for 59 Olympic athletes (32 females and 27 males) from the Chinese National Rowing Team. The coupling angles between the three pairs of segments (lumbar-pelvis, thorax-lumbar, upper arm-thorax) were generated using a vector coding method. The coupling angles were classified: in-phase, anti-phase, superior-phase, and inferior-phase. Three-way, mixed-model ANOVA were used to test the time spent in each coordination pattern. The trunk segments and upper arms demonstrated an in-phase coordination pattern for most of the time. During the drive phase, the time spent in in-phase was increased at higher stroke rates. Athletes are encouraged to use this in-phase pattern, especially between the pelvis and lumbar spine during training with high demands of stroke repetitions or time. During the recovery phase, the trunk segments were rotating mostly in-phase whereas the upper arm was flexing dominantly to maintain stroke length at higher stroke rates. Female and male rowers exhibited similar intra-trunk coordination patterns except for the upper arm-thorax pair. [ABSTRACT FROM AUTHOR]

Trunk strength plays a vital role in athletic performance, rehabilitation and general health, however, current assessment methods are expensive, non-portable or unreliable. This study aimed to investigate the within- and between-session reliability, variability, standard error of measurement and minimal detectable change (MDC) of trunk strength in the sagittal (flexion and extension) and frontal planes (left and right lateral flexion) using a fixed digital dynamometer. Eighteen participants (ten men and eight women) attended two sessions separated by 7 days. Participants were fitted with a trunk harness which was secured to an immovable base via a digital dynamometer. Three maximal voluntary isometric contractions were completed across four positions (prone, supine, left-side recumbent and right-side recumbent, respectively) on a glute-hamstring raise machine. All positions demonstrated excellent reliability and low variability within session (ICC: 0.95–0.98; CV: 5–7%) and between sessions (ICC: 0.98–0.99; CV: 4–6%), across all positions. The between-session MDC ranged from 8% (prone) to 13% (right-side recumbent), translating to absolute values between 2.9 and 3.2 kg across all positions. Maximal isometric force testing using a fixed digital dynamometer provides reliable measurements of multiplanar trunk strength, providing a practical method for use in clinical practice. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbar stabilization exercises (LSE) provide dynamic trunk stability, promote muscle strength and endurance, and improve low back pain rehabilitation and performance. OBJECTIVE: To clarify the differences in trunk muscle activity during LSEs on stable and different unstable surfaces. METHODS: Fifteen healthy males performed three exercises (elbow-toe, hand-knee, and side bridge) on stable (floor) and unstable surfaces. Muscle activity of the bilateral rectus abdominis, internal oblique, external oblique, and erector spinae were recorded. Data were compared using the Friedman test. Pairwise comparisons were performed using Wilcoxon's signed rank test if significant differences were observed. RESULTS: In the elbow-toe exercise, muscle activity of the rectus abdominis and right internal oblique increased in the following order: floor, low-difficulty, and high-difficulty unstable surface. In the hand-knee exercise, muscle activity of the internal oblique on the lower-extremity elevated side, external oblique, and erector spinae on the upper-extremity elevated side were greater on unstable surface exercise performance. In the side bridge exercise, rectus abdominis muscle activity was highest on a high-difficulty unstable surface. CONCLUSION: Trunk muscle activity increased during exercise on unstable surfaces. Since the effects of unstable surfaces vary depending on muscle and exercise types, exercise difficulty and surface stability must be considered accordingly. [ABSTRACT FROM AUTHOR]

BACKGROUND: Body tilt changes could affect the intensity/difficulty of core stability exercises, but there is still a lack of knowledge about its impact. OBJECTIVE: To analyse the trunk muscles activation during prone plank exercises at different body tilts. METHODS: Twenty-four young adults who performed recreational gymnastic activities participated in this study. Electromyography activity of the rectus abdominis (RA), external oblique (EO), internal oblique (IO) and erector spinae (ES) was recorded during the performance of six variations of the prone plank exercise (planking with feet supported on the ground [conventional horizontal position] and planking with feet supported on wall bars at five different heights increasing the angle tilt) and an inverted position exercise. RESULTS: The RA, EO and IO activation in all prone plank variations were higher than those observed in the conventional prone plank. In addition, the coefficient of variation of the muscle activation increased with the declination angle, reaching the highest values in the inverted position for the RA and ES muscles. CONCLUSION: The results seem to indicate that the body tilt variation could be used as an easy and inexpensive strategy for modulating the neuromuscular demands and the motor control challenge during planking exercises. [ABSTRACT FROM AUTHOR]

Objective The long-term effects of the unilateral muscle-sparing pedicled transverse rectus abdominis myocutaneous (TRAMmsp) flap procedure on trunk muscle performances and core stability were investigated in women with breast cancer. Methods Forty women (mean age = 42.6 years) who had received breast reconstruction with the unilateral TRAMmsp flap procedure no less than 6 months earlier (mean = 10.3 [standard deviation, SD = 4.9] months) (TRAM group) participated, and 30 women who were healthy and matched for age (mean age = 41.2 years) served as controls (control group). Their abdominal and back muscle strength was assessed using the curl-up and prone extension tests, respectively, and their static abdominal muscle endurance and back extensor endurance were assessed using the sit-up endurance test in the crook-lying position and the Biering-Sørensen test, respectively. Core stability strength was assessed using a 4-level limb-lowering test (abdominal muscle test), and core stability endurance was assessed while lying supine with both flexed legs 1 inch off the mat while keeping the pelvis in a neutral position with a pressure biofeedback unit. Results Compared with the control group, trunk muscles of the TRAM group were weaker, showing less endurance, as were their core stability strength and endurance. Static trunk muscle endurances and trunk flexion strength were associated with core stability in both groups. Conclusions Women exhibit trunk flexor and extensor weakness along with poor endurance and impaired core stability even after an average of 10 months from receiving the TRAMmsp flap procedure. Immobilization after surgery, with possible systemic inflammatory effects from surgery and chemotherapy, might have further contributed to the generalized weakness subsequent to the partial harvesting of the rectus abdominis. Impact Women after breast reconstruction with the TRAMmsp flap procedure show long-lasting deficits of strength and endurance in abdominal muscles, back extensors, and core stability. Proactive measures including early detection and evaluation of impairments as well as timely intervention targeting these clients are important to minimize the dysfunction and support their return to community participation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Despite advances in stroke rehabilitation, challenges in upper limb motor recovery and postural stability persist, negatively affecting overall well-being. Arm slings and shoulder braces have been proposed to address these issues, but their efficacy in promoting postural stability remains unclear. OBJECTIVE: This pilot randomized controlled study aimed to evaluate the impact of a new shoulder brace (N1-Neurosling) on trunk postural stability during walking, pain, and upper limb muscle strength in chronic stroke survivors. METHODS: Twenty-four adult chronic stroke patients were involved and randomly assigned to the shoulder brace group (SBg) or control group (CTRLg). Were assessed at baseline (T0) and after 4 weeks (T1) through the Trunk Control Test, the Numerical Rating Scale, the Motricity Index, Manual Muscle Test, and instrumental wearable-based assessment. RESULTS: After 4 weeks, the SBg showed significant improvement in Trunk Control Test scores (p = 0.020) and smoothness of gait measured by log dimensionless jerk along the Antero-Posterior axis (– 5.31±0.25 vs. – 5.18±0.27, p = 0.018) compared to the CTRLg. The SBg also demonstrated a reduction in pain in the shoulder girdle and enhanced upper limb muscle strength. CONCLUSION: The use of the N1-Neurosling shoulder brace led to improvements in postural stability and smoothness of gait in stroke patients. [ABSTRACT FROM AUTHOR]

This study aims to investigate the inrun position in ski-jumping, in search for factors increasing the inrun speed without compromising the take-off. The inrun position of eight World Cup (WC) and fifteen Continental Cup (COC) ski jumpers were investigated in a wind tunnel at NTNU. A preferred position, replicating a jumper's position in competition, was measured for each athlete. Improvements, based on common sense aerodynamics, with the aim to improve the aerodynamic drag were executed. The aerodynamically best of these was compared with the preferred position. A numerical model simulating the inrun speed in ski-jumping hills was used to evaluate the impact the results will have in different hill sizes, for comparisons of drag measurements and inrun speed in competitions. In the preferred position, COC had 15.5% higher drag area than the WC athletes. In their best tested position, a group difference of 10.8% was found. These differences correspond with speed differences between 0.4 and 1.3 kmh−1, or 1–3 gates (as found by the numerical model). Group difference in drag was explained by a larger trunk angle for COC. Both groups improved from their preferred to their best position, due to reductions in thigh and leg angle. [ABSTRACT FROM AUTHOR]

Unanticipated trunk perturbation is commonly observed when anterior cruciate ligament (ACL) injuries occur during direction-changing manoeuvres. This study aimed to quantify the effect of mid-flight medial-lateral external trunk perturbation directions/locations on ACL loading variables during sidestep cuttings. Thirty-two recreational athletes performed sidestep cuttings under combinations of three perturbation directions (no-perturbation, ipsilateral-perturbation, and contralateral-perturbation relative to the cutting leg) and two perturbation locations (upper-trunk versus lower-trunk). The pushing perturbation was created by customised devices releasing a slam ball to contact participants near maximum jump height prior to cutting. Perturbation generally resulted in greater peak vertical ground reaction force and slower cutting velocity. Upper-trunk contralateral perturbation showed the greatest lateral trunk bending away from the travel direction, greatest peak knee flexion and abduction angles, and greatest peak internal knee adduction moments compared to other conditions. Such increased ACL loading variables were likely due to the increased lateral trunk bending and whole-body horizontal velocity away from the cutting direction caused by the contralateral perturbation act at the upper trunk. The findings may help understand the mechanisms of indirect contact ACL injuries and develop effective cutting techniques for ACL injury prevention. [ABSTRACT FROM AUTHOR]

Impairments of postural responses are a salient feature of children with cerebral palsy (CP). While the systems approach describes balance in seven components, the relationship between trunk control and balance in children with CP has not been previously examined with all seven of these components. In this study, we aimed to identify correlations between trunk control and all seven systems approach balance components in children with bilateral spastic CP. Our participants were 30 children (M age = 11.83, SD = 2.32 years) with CP having a Gross Motor Function Classification System level ranging from I to III. We assessed trunk control with the Trunk Control Measurement Scale, including static and dynamic balance (selective voluntary control and reaching). Balance in standing was assessed using Kids-Mini-BESTest involving four domains: anticipatory, reactive, sensory orientation and stability in gait. We used Spearman's rank correlations to correlate trunk control and balance, and we obtained a moderate correlation between the trunk control measurement scale and the Kids-Mini-BESTest in children with both bilateral spastic CP (rs =.618, p <.001) and spastic diplegic CP (rs =.52, p =.02). Analysis of the correlations between separate domains of the Kids-Mini-BESTest and the trunk control measurement scale subscales revealed moderate correlations between the static sitting balance subscale and all four domains of the Kids-Mini-BESTest. The dynamic selective motor control subscale of the trunk control measurement scale moderately correlated with the anticipatory domain of the Kids-Mini-BESTest. The dynamic reaching subscale also correlated moderately with anticipatory and stability in gait domains. This correlation was statistically significant in the 13 to 17-year-old age group and was strong among females, whereas the correlation was moderate in males. Trunk control was moderately associated with balance considering all the systems theory components of balance in children with bilateral spastic cerebral palsy. [ABSTRACT FROM AUTHOR]

The Overhead Squat (OHS) and Single-Leg Squat (SLS) are two clinical tests used by practitioners to identify high-risk biomechanical movement patterns. Several published studies have reported sex differences in SLS performance; however, few have investigated variations during the OHS and none has measured kinematics with a marker-less motion capture system. Therefore, this study aimed to compare biomechanical movement patterns between male and female collegiate athletes during OHS and SLS testing. Seventy-five females and 58 male athletes completed OHS and SLS. A Microsoft Kinect sensor using Athletic Movement Assessment software (PhysiMax®) was used to measure kinematics. For the OHS, males displayed greater peak knee frontal plane projection angles (FPPA) (M:26°±10°, F:20°±8°; P < 0.05), peak hip flexion (M:-94°±14°, F:-87°±15°; P < 0.05), and peak trunk flexion angles (M:11°±11°, F:6°±9°; P < 0.05). For the SLS (dominant-limb), males displayed greater peak trunk flexion (M:32°±6°, F:27°±7°; P < 0.05). For the non-dominant limb, females displayed greater peak knee FPPA (F:-12°±9°, M:-8°±9°; P < 0.05) whereas males displayed greater peak trunk flexion angles (M:32°±5°, F:27°±7°; P < 0.05). These findings suggest the need for practitioners to develop sex-specific corrective exercise programmes in effort to improve lower extremity kinematics in athletes. [ABSTRACT FROM AUTHOR]

Objectives: Determine if (a) a better trunk stability and endurance are associated with an improved whole‐body dynamic balance, and if (b) the assessment tests can be interchanged within each capability. Methods: Sixty‐three physically active young males performed three trunk stability (i.e., the lumbopelvic stability, the unstable sitting and the sudden loading sitting tests), three trunk muscle endurance (i.e., the Biering–Sørensen, the side bridge and the front bridge tests) and four whole‐body dynamic balance (i.e., the tandem and the single‐leg stance, the Y‐Balance, and the single‐leg triple hop tests) tests two times. After assessing the reliability of the variables, a Pearson correlation analysis was performed. Results: The correlations between trunk stability and endurance tests with dynamic balance tests were non‐significant except for the unstable sitting test with both the tandem (r = 0.502) and the single‐leg stance (r = 0.522) tests. Moreover, no relationships were observed between the trunk stability and the trunk muscle endurance tests. Interestingly, no relationships were found between most tests within each capability (i.e., trunk stability, trunk endurance, and dynamic balance) except: (i) the front bridge stability test and the back (r = 0.461) and the side (r = 0.499) bridge stability tests; (ii) the two side bridge endurance tests (r = 0.786); (iii) the tandem and the single‐leg stance tests (0.439 ≤ r ≤ 0.463); (iv) the Y‐Balance and the single‐leg triple hop tests (0.446 ≤ r ≤ 0.477). Conclusion: Better trunk function does not seem to be a relevant factor for dynamic balance in young active males. In this population, specific measures are needed as the test interchangeability is questioned. [ABSTRACT FROM AUTHOR]

The purpose was to compare two non-laboratory based running retraining programs on lower limb and trunk kinematics in recreational runners. Seventy recreational runners (30 ± 7.3 years old, 40% female) were randomised to a barefoot running group (BAR), a group wearing a digital metronome with their basal cadence increased by 10% (CAD), and a control group (CON). BAR and CAD groups included intervals from 15 to 40 min over 10 weeks and 3 days/week. 3D sagittal kinematics of the ankle, knee, hip, pelvis, and trunk were measured before and after the retraining program, at comfortable and high speeds. A 3 × 2 mixed ANOVA revealed that BAR and CAD groups increased knee and hip flexion at footstrike, increased peak hip flexion during stance and flight phase, decreased peak hip extension during flight phase, and increased anterior pelvic tilt at both speeds after retraining. In addition, BAR increased ankle plantar flexion at footstrike and increased anterior trunk tilt. Both retraining programs demonstrated significant moderate to large effect size changes in parameters that could reduce the mechanical risks of injury associated with excessive knee stress, which is of interest to coaches, runners and those prescribing rehabilitation and injury prevention programs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is the most common structural deformity of the spine during adolescence, which could cause varying degrees of physical and mental damage to patients. Schroth therapy and sling exercise are widely used in the treatment of patients with AIS currently, and have shown the significant therapeutic effect relatively. OBJECTIVE: To observe the efficacy of sling exercise combined with Schroth therapy on adolescents with mild idiopathic scoliosis (MIS). METHODS: Sixty patients with AIS were randomly divided into the Schroth + sling group (n = 31) and the Schroth group (n = 29). Patients in both groups received Schroth therapy, and sling exercise was added in the Schroth + sling group. Before and after 12 weeks of treatment, the Cobb angle, angle of trunk rotation (ATR), Scoliosis Research Society-22 (SRS-22) scale score and averaged electromyography (AEMG) of bilateral paraspinal muscles were evaluated. RESULTS: After the treatment, Cobb angle, ATR in both groups were decreased compared with those before (P < 0.001), and the decrease in the Schroth + sling group was more obvious (P < 0.05). The AEMG of bilateral paraspinal muscles and the total score, posture, mental health of SRS-22 of the two groups improved compared with those before treatment (P < 0.05), and the Schroth + sling group had a significant improvement than the Schroth group (P < 0.05). CONCLUSION: Schroth therapy improved the degree of scoliosis, torticollis, quality of life, and bilateral paraspinal strength on adolescents with mild idiopathic scoliosis. The effect was more pronounced when the sling exercise was included in the treatment regimens. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have shown that core muscle training can accelerate the recovery of motor function in stroke patients. However, there are no relevant reports to show the effect of core muscle training combined with functional electrical stimulation (FES) on the rehabilitation of stroke patients. OBJECTIVE: This study aimed to observe the efficacy of core muscle training combined with FES on motor and balance functions of lower limbs in stroke patients. METHODS: This study selected and divided 120 stroke patients with hemiplegia admitted to our hospital into the control and observation groups. Patients in the control group just received core muscle training; while patients in the observation group were treated by core muscle training combined with FES. Both groups were treated for 8 weeks. Subsequently, the clinical data and information of all patients were collected and counted. Muscle strength changes were observed by detecting paralytic dorsiflexor (pDF), plantar flexor (pPF), knee extensor (pKE), and knee flexor (pKF) before and after treatment. Motor and balance abilities of both groups were scored through the 10-meter walking test (10 MWT), Berg balance scale (BBS), functional ambulation category (FAC) scale, timed up and go (TUG) test, and lower extremity motricity index (MI-Lower). RESULTS: No significant difference was found in clinical data between the two groups. The intensity of pDF, pPF, pKE, and pKF significantly increased in both groups after treatment, and the intensity of these parameters was higher in the observation group relative to the control group. Additionally, 10 MWT and TUG test scores of patients in the observation group were notably decreased while the BBS and MI-Lower scores were significantly increased after treatment compared with those in the control group. CONCLUSION: Core muscle training combined with FES can significantly improve the rehabilitation effect of lower limb motor and balance functions in stroke patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Previous studies have suggested an association between pelvic rotation (PR) and scoliotic deformity in severe adolescent idiopathic scoliosis (AIS), but none have investigated this relationship in mild to moderate AIS. OBJECTIVE: To investigate the relationship between PR and trunk rotation in mild to moderate AIS. METHODS: This was a case-control study. The cases were 32 AIS patients with PR in the opposite direction to the thoracic curve, and the controls were 32 AIS patients with PR in the same direction as the thoracic curve. All patients were assessed with the Adams forwards bend test. Type II trunk rotation was selected as exposure. Logistic regression was used to estimate the association between PR direction and types of trunk rotation while accounting for confounders. Multiple linear regression was used to analyse the relationships between PR magnitude and the angle of trunk rotation (ATR). RESULTS: Logistic regression showed an unadjusted OR of 9.13 (95% CI 2.92–28.50, P < 0.001), and adjustment for sex and Cobb angle only slightly changed the OR (adjusted OR, 8.23; 95% CI, 2.51–27.01; P = 0.001). The concave/convex ratio was associated with ATR measurements in both cases (β = - 0.379; P = 0.030) and controls (β = - 0.468, P = 0.008). CONCLUSION: An association was found between PR and trunk rotation, which may help achieve more effective physiotherapy in mild to moderate AIS. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chronic low back pain (LBP) can lead to muscle spasms, limited range of motion, and abnormal posture, resulting in trunk muscle asymmetry. OBJECTIVE: This study aimed to assess the intra- and inter-rater reliability of a quantitative measurement of trunk coronal asymmetry in patients with chronic LBP, minimizing unnecessary gravity and friction force using a manual table in the prone position. METHODS: This prospective study was conducted at a single center, targeting patients with chronic LBP to measure trunk coronal asymmetry on a manual table in the prone position. The intra-class correlation coefficient (ICC) was calculated using one-way random-effects and two-way mixed-effects models. RESULTS: Fifty-eight patients who had LBP for more than three months were enrolled from May 1, 2021, to December 31, 2021. The intra- and inter-rater reliabilities of the two examiners' measurements were 0.872 and 0.899, and 0.852, respectively. Based on pain severity, the participants were classified into mild and severe groups, with ICCs of 0.823 and 0.889, and 0.936 and 0.918, respectively. CONCLUSION: Measurement of trunk coronal asymmetry in the prone position using a manual table demonstrates high intra- and inter-rater reliability. In addition, the reliability increases with greater pain severity. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to compare three-dimensional kinematic of the trunk, pelvis, hip, and knee during the single-leg squat and hip torque in individuals with and without isolated patellofemoral osteoarthritis (PFOA). Patients and methods: This cross-sectional study evaluated trunk, pelvis, hip, and knee kinematics at 30°, 45°, and 60° knee flexion during the single-leg squat using the Vicon motion capture and analysis system, the Nexus System 2.1.1, and 3D Motion Monitor software. Sixteen individuals (8 males, 8 females; mean age: 49.3±6.2 years; range 40 to 61 years) participated in the study, of which eight were PFOA patients and eight were healthy controls. Isometric hip abductor, extensor, and external rotator torques were evaluated using a handheld dynamometer. Results: The PFOA group exhibited greater hip adduction at 30° (p=0.008), 45° (p=0.005), and 60° (p=0.008) knee flexion in the descending phase of the single-leg squat, as well as at 60° (p=0.009) and 45° (p=0.03) knee flexion in the ascending phase. No significant differences were found between groups for other kinematic variables (p>0.05). The PFOA group exhibited lower isometric hip abductor (p=0.02), extensor (p<0.001), and external rotator (p=0.007) torques. Conclusion: Individuals with PFOA exhibited excessive hip adduction that could increase stress on the lateral patellofemoral joint at 30°, 45°, and 60° knee flexion during the single-leg squat and exhibited weakness of the hip abductors, extensors, and external rotators in comparison to healthy controls. [ABSTRACT FROM AUTHOR]

Context: The importance of isometric trunk strength (ITS) among sport science professionals is higher than its actual reported effect size on either performance or low back pain (LBP) occurrence. Objective: To provide normative values of ITS and strength ratios, and to evaluate the effect of sex, sports discipline, and LBP status. Design: Crossover study. Setting: University research laboratory. Participants: Five hundred and sixty-seven elite athletes (186 females) with and without a history of LBP from different sports. Main Outcome Measure: Participants underwent ITS testing for trunk flexors, extensors, and lateral flexors. Normalized maximal strength (in newton meter per kilogram) and strength ratios were calculated. Differences between sex, LBP, and sport disciplines were assessed with 3-way analysis of variance (sex x LBP status x 7 sport categories) and partial eta-squared (ηp²) effect size. The predictive validity of ITS for LBP was checked with receiver operating characteristics (area under the curve). Results: The authors found significant differences in extensor and flexor ITS in favor of male athletes (medium ηp², P < .05), while sex differences in lateral flexion ITS had a low size effect (P < .05). A low size effect was also observed for the differences in strength ratios extensors/flexors (mean 1.47; 95% confidence interval, 1.45-1.50) and left flexors/right flexors (mean 0.99; 95% confidence interval, 0.98-1.01) among sexes. The sport discipline-related differences generally had a low size effect. No significant differences in ITS were found between LBP and LBP-free athletes. Only 50% to 58% of athletes (area under the curve, 0.501-0.582) were correctly classified as LBP or LBP-free using different ITS and strength ratio variables. Conclusions: ITS and strength ratios have low predictive validity for LBP history but may discriminate between sex and sport disciplines. Our data are a useful reference point for meaningful individual results interpretation when athletes are evaluated during training or rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: We quantified the relationship between high-density surface electromyographic (HDsEMG) oscillations (in both time and frequency domains) and torque steadiness during submaximal concentric/eccentric trunk extension/flexion contractions, in individuals with and without chronic low back pain (CLBP). Methods: Comparisons were made between regional differences in HDsEMG amplitude and HDsEMG–torque cross-correlation and coherence of the thoracolumbar erector spinae (ES), rectus abdominis (RA), and external oblique (EO) muscles between the two groups. HDsEMG signals were recorded from the thoracolumbar ES with two 64-electrode grids and from the RA and EO muscles with a single 64-electrode grid placed over each muscle. Torque signals were recorded with an isokinetic dynamometer. Coherence (δ band (0–5 Hz)) and cross-correlation analyses were used to examine the relationship between HDsEMG and torque signals. For this purpose, we used principal component analysis to reduce data dimensionality and improve HDsEMG-based torque estimation. Results: We found that people with CLBP had poorer control during both concentric and eccentric trunk flexion and extension. Specifically, during trunk extension, they exhibited a higher HDsEMG–torque coherence in more cranial regions of the thoracolumbar ES and a higher HDsEMG cross-correlation compared with asymptomatic controls. During trunk flexion movements, they demonstrated higher HDsEMG amplitude of the abdominal muscles, with the center of activation being more cranial and a higher contribution of this musculature to the resultant torque (particularly the EO muscle). Conclusions: Our findings underscore the importance of evaluating torque steadiness in individuals with CLBP. Future research should consider the value of torque steadiness training and HDsEMG-based biofeedback for modifying trunk muscle recruitment strategies and improving torque steadiness performance in individuals with CLBP. [ABSTRACT FROM AUTHOR]

The purposes of this study were to 1) develop a simulation model of baseball batting utilising the standard motion, and 2) explore optimal motions of the upper body to increase the bat-head speed. Twenty-three male collegiate baseball players performed tee batting set at waist height. A ten-segment angle-driven simulation model consisting of a bat and upper body was driven using with the coordinate data of the standard motion. Performance optimisation was conducted to find joint angle time histories of the upper body that increase the maximum bat-head speed. In the evaluation of the simulation model, the root mean square error between the measured and simulation model was 0.19 m/s and 0.98° for the time histories of the bat-head speed and bat orientation angle. Performance optimisation was able to achieve a targeted increase in bat-head speed (35.6 m/s to 40.0 m/s) through greater barrel-side shoulder abduction, knob-side elbow flexion, and torso right lateral flexion around ball impact resulted in the bat accelerating in the hitting direction. It is concluded that the proposed simulation approach can be applied as a tool for further simulation analysis in various complex sporting motions. [ABSTRACT FROM AUTHOR]

Latissimus dorsi may contribute to trunk movement and control because of its extensive attachments to the trunk. However, electromyography studies have shown highly variable activity levels during trunk tasks. To critically evaluate whether latissimus dorsi has a role in trunk movement and/or control. Studies assessing the activation of latissimus dorsi using electromyography during trunk movements and/or trunk stability tasks were sourced (May 2022). Risk of biases and quality of evidence was assessed. Activation levels were pooled and meta-analysed where possible. Thirty nine of 6125 studies identified in the search met the inclusion criteria. The meta-analyses showed high latissimus dorsi activity levels (60% maximal voluntary contraction [MVC]) during ipsilateral trunk rotation and low levels (<20% MVC) during contralateral trunk rotation, extension and stability tasks. Considerable variability of activity levels existed between studies when using high loads. Quality of evidence was very low to moderate. Although high activity levels were found during ipsilateral trunk rotation, there is very low confidence that these activity levels reflect the true levels. There is moderate confidence latissimus dorsi has a limited contribution to trunk control. The use of surface electrodes and non-validated normalisation processes were critical methodological issues that contributed to lower quality of evidence. [ABSTRACT FROM AUTHOR]

Introduction: Crossfit is a sport that combines cardio‐respiratory and muscle endurance, strength, flexibility, muscle power, speed, coordination, agility and balance. However, there is no information in the literature regarding functional performance of the lower limbs and the endurance of core muscles in this population. The objective of this study was to evaluate the correlation between trunk strength/endurance and lower limb function through lower limb symmetry and balance tests. Methods: Forty‐one young adults aged 19–41 years (26.3 ± 5.4) participated, 15 sedentary and 26 cross fit practitioners for at least one year. The tests were as follows: Biering‐Sørensen Test of trunk extensor endurance, Trunk Flexors Endurance Test at 60°, Side Plank Endurance Test, Lumbar Dynamometry, Single‐Leg Hop Test and Star Excursion Balance Test. Results and Discussion: Although there were higher values, there was no significant difference (p > 0.05) between the groups for lower limb symmetry and strength of trunk flexor muscles. For balance, strength and resistance variables of trunk extensor muscles, the values found were higher in crossfit practitioners than in sedentary subjects. Conclusion: There is a relationship between trunk muscle strength and endurance and lower limb balance. Moreover, cross fit athletes showed higher values of trunk muscle strength/endurance and lower limb balance compared to sedentary adults. [ABSTRACT FROM AUTHOR]

The psychometric qualities of the proprioception and dynamic trunk control tests have rarely been studied in individuals after stroke. To investigate the reliability and validity of the Trunk Position Sense Test (TPS) and Modified Functional Reach Test (MFRT) in persons after stroke. Thirty-two participants were included. The TPS and MFRT were assessed by two physiotherapists during a first session. After resting, a second session was conducted. The intraclass correlation coefficient (ICC) was calculated to assess the test–retest (ICC3,k) and inter-rater reliability (ICC2,k). Pearson correlations coefficients were calculated between TPS/MFRT performances and clinical tests (trunk strength, Timed Up and Go and Balance Assessment in Sitting and Standing Positions – BASSP). The TPS inter-rater reliability was good for vertical error (ICC = 0.75 [0.50–0.88]) while it was moderate for horizontal error (ICC = 0.48 [0.10–0.75]) as well as for test–retest reliability (0.39 ≤ ICC ≤ 0.59). As for the MFRT, inter-rater (0.76 ≤ ICC ≤ 0.90) and test–retest reliability (0.71 ≤ ICC ≤ 0.91) were good to excellent for anterior, paretic et non-paretic displacements. Horizontal errors for the TPS (−0.26 ≤ r ≤ −0.36) and anterior MFRT (0.38 ≤ r ≤ 0.64) values correlated moderately with trunk strength. The MFRT is a reliable test for persons after stroke with trunk control impairments. The TPS does not appear to be relevant for post-stroke individuals. This can be explained by the fact that its procedure is not easily applied for individuals after stroke – who may have significant motor and cognitive impairments. [ABSTRACT FROM AUTHOR]

To compare the effects of backward (BW) and forward (FW) walking training on back geometry and mobility function in children with hemiparetic cerebral palsy (CP). Fifty-five children with hemiparetic CP participated in this study. They were randomly assigned into two groups. For 12 weeks, both groups got a conventional physical therapy program three days/week. Groups A and B got a specifically developed FW walking training (25 minutes/session) and a specially designed BW walking training (25 minutes/session), respectively. The trunk imbalance, lateral deviation, pelvic tilting, pelvic torsion, surface motion, and dynamic gait index of group B improved significantly more than group A (p <.05). Both groups showed significant improvements in all measured variables (p <.05). BW walking training might be considered as an effective therapy modality for improving back geometry and mobility function in hemiparetic CP children compared with FW walking training combined with a typical program. [ABSTRACT FROM AUTHOR]

Background/Aims: Sitting balance training is an important therapeutic tool used by physical and occupational therapists who work with patients with hemiparesis, many of whom have difficulty shifting their weight while sitting. This study assessed the immediate effects of circular trunk movements on the maximum reach distance and the centre of pressure distance that could be achieved during a multidirectional reach task in participants with post-stroke hemiparesis and healthy individuals as a control group. Methods: This non-randomised controlled study included 26 participants with hemiparesis and 10 age-matched control participants. A functional reach apparatus, body pressure distribution measuring system and digital video camera were used to measure multidirectional reach, centre of pressure trajectories and circular trunk movements. The participants completed the assessments in the following order: multidirectional reach, circular trunk movements and repeat multidirectional reach. The authors classified the centre of pressure trajectories into type A (oval) and type B (non-oval) tracings according to the shape displayed by the circular trunk movements, which corresponded to the level of trunk function. The reach distance and centre of pressure distance before and after the circular trunk movements were compared. Results: The reach distance and centre of pressure distance values in the front direction of participants with hemiparesis who exhibited type A tracings and had higher trunk function were significantly greater after completing circular trunk movements. In contrast, the reach distance and centre of pressure distance values of participants in all directions who exhibited type B tracings and had lower trunk function were significantly greater after completing circular trunk movements. Conclusions: Circular trunk movements appeared to affect both reach distance and centre of pressure distance, particularly in participants with hemiparesis with type B tracings and lower trunk function. Implications for practice: Physical and occupational therapists could incorporate circular trunk movements into rehabilitation programmes to help individuals with post-stroke hemiparesis improve their reach distance, trunk function and ability to shift their weight while sitting. [ABSTRACT FROM AUTHOR]

L'objectif principal était d'évaluer les effets d'un cycle d'étirement et de renforcement des muscles antérieurs et postérieurs du tronc chez des cavaliers professionnels en formation. Au total, 18 cavaliers futurs professionnels ont été divisés en 2 groupes. L'un a bénéficié d'un cycle de 10 semaines de renforcement et étirement des muscles du tronc. Leur activité équestre a été évaluée avant et après le cycle ainsi que leur perception de douleurs lombalgiques. À l'issue du cycle de 10 semaines, le fonctionnement à cheval des cavaliers du groupe ayant participé au programme s'est significativement amélioré contrairement à celui des cavaliers du groupe témoin. Les douleurs ont diminué au repos, lors des tâches à pied et pendant l'activité à cheval. The main objective was to evaluate the effectiveness of a stretching and strengthening program of the anterior and posterior trunk muscles in future professional riders. In total, 20 future professional riders were divided into 2 groups. One of the two groups received a 10-week program of strengthening and stretching of the trunk muscles. Their movements on the horse were evaluated during a training session before and after the cycle, as well as their perception of low back pain. At the end of the 10-week program, movements of the riders in the group who have participated in the program significantly improved, unlike that of the riders in the control group. Moreover, their pain decreased at rest, during walking tasks and during riding. [ABSTRACT FROM AUTHOR]

Introduction: Lumbar lordosis is important for the spine and pelvis to work in harmony in providing trunk control and maintaining sagittal balance. Children with cerebral palsy (CP) have difficulties in providing trunk postural control and balance, which is critical for independence in daily living activities. This study was planned to examine the immediate effect of a lower-trunk orthosis supporting physiological lumbar lordosis on trunk control and upper-limb functionality in children with CP. Objectives and Methods: A total of 30 children with CP, 13 diparetic, 11 hemiparetic, and 6 ataxic, 21 ambulatory (GMFCS I/II), and 9 nonambulatory (GMFCS III/IV) aged 3-16 years were included in the study. The Pediatric Functional Reach Test (PFRT) and the Seated Postural Control Measure (SPCM) were used to assess trunk control; the Pediatric Berg Balance Scale (PBBS) was used to assess balance; and the Box and Block Test (BBT) and the Nine-Hole Peg Test (9HPT) were used to evaluate upper-limb functions. All tests were performed with and without a soft lumbosacral brace. The braces were made of soft, elastic fabric with steel, and weremade by the orthotic technician in four different sizes. The angle of lordosis was adjusted with steel underwires according to each child. The existing physiological lordosis of the child is supported by the brace. It is not intended to increase or decrease. Results: In the study, the results of all evaluations with a brace were better than those without a brace (P < 0.05). No significant difference was found only in the functional part of the SPCM test (P > 0.05). Conclusions: Our study revealed that soft lumbosacral orthosis, which supports physiological lordosis, has a positive effect on trunk stability and upper-limb functionality in children with CP. Clinical Relevance: In children's trunk stability and upper-limb functionality studies, the use of soft lumbosacral orthosis that supports physiological lordosis can be added to rehabilitation programs and daily living activities as a support. [ABSTRACT FROM AUTHOR]

The torso muscles play important roles in longitudinal rotation between the upper and lower torso on land but demands on these muscles at different swimming speeds and their role in torso twist in front crawl remains unclear. We aimed to compare torso muscle activity at different front crawl speeds and to assess the relationships between torso muscle activity and torso twist. Three-dimensional kinematics and torso muscle EMG data were collected from 15 male swimmers during middle-distance and sprint front crawl. Internal oblique, external oblique, and rectus abdominis, but not erector spinae, activities were greater at sprint than middle-distance pace. Sprint swimmers are likely to benefit from focusing training on the abdominal muscles. Cross-correlation peak coefficients between muscle activity and torso twist occurred with 517–775 and 400–600 ms lag at middle-distance and sprint paces (respectively). These lags are beyond the torso muscle electromechanical delay (~220 ms) and are too long for these muscles to produce movement changes. Further, peak coefficients coincided with both positive and negative shifts, indicating that muscle activity did not always precede kinematic changes. The torso muscles are therefore likely to play a greater role in maintaining stability and controlling posture in front crawl than producing torso twist. [ABSTRACT FROM AUTHOR]