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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]

Multiple sclerosis is a neurodegenerative disease that causes balance deficits, even in early stages. Evidence suggests that people with multiple sclerosis (PwMS) rely more on vision to maintain balance, and challenging balance with optical flow perturbations may be a practical screening for balance deficits. Whether these perturbations affect standing balance in PwMS is unknown. Therefore, the purpose of this study was to examine how optical flow perturbations affect standing balance in PwMS. We hypothesized that perturbations would cause higher variability in PwMS compared with matched controls during standing and that standing balance would be more susceptible to anterior–posterior (A–P) perturbations than medial–lateral (M–L) perturbations. Thirteen PwMS and 13 controls stood under 3 conditions: unperturbed, M–L perturbation, and A–P perturbations. A–P perturbations caused significantly higher A–P trunk sway variability in PwMS than controls, although both groups had similar center-of-pressure variability. Both perturbations increased variability in A–P trunk sway and center of pressure. Trunk variability data supported the hypothesis that PwMS were more susceptible to optical flow perturbations than controls. However, the hypothesis that A–P perturbations would affect balance more than M–L perturbations was partially supported. These results suggest potential for optical flow perturbations to identify balance deficits in PwMS. [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]

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]

The purpose of this investigation was (1) to test the effect of movement restriction of the free leg during unilateral vertical jump on performance and power output comparing 2 different jump techniques: flexed (Classic technique) and straight (FC Luzern technique) free leg, and (2) to test the correlation between performance and power output obtained using these 2 techniques. Twenty elite soccer players performed squat (SJ) and countermovement (CMJ) jumps on each leg. The jump height and peak power output were compared between the 2 techniques for both legs. The jump height and peak power were significantly higher for the classic test for SJ and CMJ (P <.001) with no side effects or interactions. The angular range of motion of the free leg was higher for the Classic test than for the FC Lucerne test (P <.001), with no difference in the angular range of motion of the trunk. A moderate correlation was found between the 2 techniques on peak power (SJ: r =.626; CMJ: r =.649) and jump height (SJ: r =.742; CMJ: r =.891). Consequently, FC Lucerne technique, limiting the contribution of the free leg, is more appropriate to assess lower limb strength capacities during unilateral jump test. [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]

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]

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]

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]

There is disagreement regarding the efficacy of 'safe' lifting recommendations for reducing low back disorder risk. These recommendations commonly focus on minimising lumbar spine flexion, which limits the range of allowable starting lift positions for that person. This study evaluated whether starting postural adaptations could allow a person to reach down further without rounding their lumbar spine before beginning a lift. Reach displacement was measured as participants performed a series of maximal reach tasks under different combinations of stance width, foot orientation and trunk inclination, with their lumbar spine motion restricted. There were no interactions between any of the three postural adaptations or any effect of stance width or trunk inclination. Seventy-nine percent of participants achieved their greatest reach displacement with their feet externally rotated, which contributed to a 4 cm greater reach displacement compared to a neutral foot orientation (p < 0.001). Practitioner summary: This study examined whether aspects of initial posture could influence the ability to adhere to 'safe' lifting recommendations across a range of lift heights. As a component of lifting (re)training interventions, practitioners should consider starting lift posture adaptations (e.g. manipulating foot external rotation) to improve capacity to adhere to recommendations. [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]

Background A strong body of literature has been published outlining muscle activity differences during sports performance in groups of overhead athletes. However, there are limited studies that have directly compared the muscle activity in overhead athletes with and without history of shoulder injury during functional everyday tasks. Purpose This study aimed to identify muscle activities across fourteen upper extremity and core muscles during three functional everyday movements in athletes with and without history of shoulder injury. Study Design Cross-Sectional Study Methods Thirty-two male overhead throwing athletes (fifteen healthy and seventeen injured) were recruited and completed three everyday functional movements of high elevation, low elevation, and rotation, using their dominant arm to move an object between two fixed positions. Electromyography (EMG) was recorded for fourteen muscles including: biceps brachii, deltoids (anterior, medial, and posterior), trapezius (upper and lower), pectoralis major, latissimus dorsi, serratus anterior, infraspinatus, external obliques, and gluteus maximus (all surface electrodes) and supraspinatus (fine wire electrode). Mixed model repeated measures ANOVA and post-hoc analysis assessed mean muscle activity (%MVC) between groups and each movement phase. Results Upper trapezius elicited higher mean activity in healthy athletes during both phases of the arm rotation task (p < 0.05). No differences between groups were evident for arm elevation tasks. Qualitative analysis of muscle patterns during functional tasks reflected a temporal shift in muscle activation timings and magnitudes between athlete groups, suggesting potential compensatory mechanisms in injured athletes. [ABSTRACT FROM AUTHOR]

This study assessed the effectiveness of a passive back support exoskeleton during a mechanical loading task. Fifteen healthy participants performed a simulated patient transfer task while wearing the Laevo (version 2.5) passive back support exoskeleton. Collected metrics encompassed L5-S1 joint moments, back and abdominal muscle activity, lower body and back kinematics, center of mass displacement, and movement smoothness. A statistical parametric mapping analysis approach was used to overcome limitations from discretization of continuous data. The exoskeleton reduced L5-S1 joint moments during trunk flexion, but wearing the device restricted L5-S1 joint flexion when flexing the trunk as well as hip and knee extension, preventing participants from standing fully upright. Moreover, wearing the device limited center of mass motion in the caudal direction and increased its motion in the anterior direction. Therefore, wearing the exoskeleton partly reduced lower back moments during the lowering phase of the patient transfer task, but there were some undesired effects such as altered joint kinematics and center of mass displacement. Statistical parametric mapping analysis was useful in determining the benefits and hindrances produced by wearing the exoskeleton while performing the simulated patient transfer task and should be utilized in further studies to inform design and appropriate usage. [ABSTRACT FROM AUTHOR]

Research indicates that increasing trunk flexion may optimize patellofemoral joint loading. However, this postural change could cause an excessive Achilles tendon force (ATF) and injury risk during movement. This study aimed to examine the effects of increasing trunk flexion during stair ascent on ATF, ankle biomechanics, and vertical ground reaction force in females. Twenty asymptomatic females (age: 23.4 [2.5] y; height: 1.6 [0.8] m; mass: 63.0 [12.2] kg) ascended stairs using their self-selected and flexed trunk postures. Compared with the self-selected trunk condition, decreases were observed for peak ATF (mean differences [MD] = 0.14 N/kg; 95% confidence interval [CI], 0.06 to 0.23; Cohen d = −1.2; P =.003), average rate of ATF development (MD = 0.25 N/kg/s; 95% CI, 0.07 to 0.43; Cohen d = −0.9; P =.010), ankle plantar flexion moment (MD = 0.08 N·m/kg; 95% CI, 0.03 to 0.13; Cohen d = −1.1; P =.005), and vertical ground reaction force (MD = 38.6 N/kg; 95% CI, 20.3 to 56.90; Cohen d = −1.8; P <.001). Increasing trunk flexion did not increase ATF. Instead, this postural change was associated with a decreased ATF rate and magnitude and may benefit individuals with painful Achilles tendinopathy. [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]

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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]

To systematically explore the effects of trunk exercises using virtual reality technology compared to conventional exercises for trunk impairment in patients with subacute and chronic strokes. A comprehensive search of literature published from inception until December 2022 was conducted using PubMed, Cochrane Library, Web of Science, Scopus, IEEE, and the Physiotherapy Evidence Database (PEDro). The inclusion criteria encompassed all randomized controlled trials (RCT) published in the English language involving adults who had had strokes and the evaluation of the effectiveness of virtual reality -based trunk exercises in reducing trunk impairment post stroke as measured by the trunk control test (TCT) and/or the trunk impairment scale (TIS) compared to conventional trunk exercises. A total of 397 studies were retrieved, and six studies were included in the current analysis. A random-effects meta-analysis of six studies indicated that video games had a very large, significant effect (SMD = 1.11; 95%, P < 0.0001) on the delivery of trunk exercises to reduce trunk impairment post stroke at both the subacute and chronic stages. The study findings indicate that trunk exercises using virtual reality have a highly significant effect on reducing trunk impairment in patients with subacute and chronic stroke. Large RCTs are needed to study the effects of virtual reality trunk exercises on the acute, subacute, and chronic stages of stroke. [ABSTRACT FROM AUTHOR]

Introduction: Clinical assessment of upper limb sensorimotor function poststroke is often constrained by low sensitivity and limited information on movement quality. To address this gap, recent studies proposed a standardized instrumented drinking task, as a representative daily activity combining different components of functional arm use. Although kinematic movement quality measures for this task are well-established, and optical motion capture (OMC) has proven effective in their measurement, its clinical application remains limited. Inertial Measurement Units (IMUs) emerge as a promising low-cost and user-friendly alternative, yet their validity and clinical relevance compared to the gold standard OMC need investigation. Method: In this study, we conducted a measurement system comparison between IMUs and OMC, analyzing 15 established movement quality measures in 15 mild and moderate stroke patients performing the drinking task, using five IMUs placed on each wrist, upper arm, and trunk. Results: Our findings revealed strong agreement between the systems, with 12 out of 15 measures demonstrating clinical applicability, evidenced by Limits of Agreement (LoA) below the Minimum Clinically Important Differences (MCID) for each measure. Discussion: These results are promising, suggesting the clinical applicability of IMUs in quantifying movement quality for mildly and moderately impaired stroke patients performing the drinking task. [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]

Background: The trunk being central key point of body, proximal trunk control is a pre-requisite for distal limb movement control, balance and functional activities. Sufficient trunk stability and control of trunk movements are essential for postural stability and normal gait as the upper body constitutes two thirds of the total body weight. In Parkinson's disease approximately 13% to 33% of patients present with postural instability as their initial Motor symptom. So, purpose of this study was to compare the effect of Swiss ball trunk training exercise and trunk exercise on a bed for trunk control in Parkinson's patients. Method: Total 30 Parkinson's patient were selected for the study as per selection criteria and divided into two groups (15 in each group). group A was treated with trunk exercise on Swiss ball and group B was treated with trunk exercise on bed. each subject received treatment for 3 weeks,4 days/week. An assessment was done prior to treatment and after 3 weeks using Trunk Impairment Scale test. Inter-group analysis by unpaired t-test showed statistically significant improvement on Trunk Impairment Scale. (P value ≤0.05) Conclusion: The Swiss ball trunk training exercise and trunk exercise on a bed had a significant effect on trunk control. Out of the two treatment Swiss ball trunk training had a more significant effect on improving trunk control. [ABSTRACT FROM AUTHOR]

Dual-task walking and cell phone usage, which is associated with high cognitive load and reduced situational awareness, can increase risk of a collision, a fall event, or death. The objective of this study was to quantify the effect of dual-task cell phone talking, texting, and reading while walking on spatiotemporal gait parameters; minimum foot clearance; and dynamic stability of the lower limb joints, trunk, and head. Nineteen healthy male participants walked on an instrumented treadmill at their self-selected speed as well as walking while simultaneously (1) reading on a cell phone, (2) texting, and (3) talking on a cell phone. Gait analyses were performed using an optical motion analysis system, and dynamic stability was calculated using the Maximum Lyapunov Exponent. Dual-task cell phone usage had a significant destabilizing influence on the lower limb joints during walking. Cell phone talking while walking significantly increased step width and length and decreased minimum foot clearance height (P <.05). The findings suggest that dual-task walking and cell phone conversation may present a greater risk of a fall event than texting or reading. This may be due to the requirements for more rapid information processing and cognitive demand at the expense of motor control of joint stability. [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 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]

A pitcher's ability to achieve pitch location precision after a complex series of motions is of paramount importance. Kinematics have been used in analyzing performance benefits like ball velocity, as well as injury risk profile; however, prior utilization of such data for pitch location metrics is limited. To develop a pitch classifier model utilizing machine learning algorithms to explore the potential relationships between kinematic variables and a pitcher's ability to throw a strike or ball. This was a descriptive laboratory study involving professional baseball pitchers (n = 318) performing pitching tests under the setting of 3D motion-capture (480 Hz). Main outcome measures included accuracy, sensitivity, specificity, F1 score, positive predictive value (PPV), and negative predictive value (NPV) of the random forest model. The optimized random forest model resulted in an accuracy of 70.0 %, sensitivity of 70.3 %, specificity of 48.5 %, F1 equal to 80.6 %, PPV of 94.3 %, and a NPV of 11.6 %. Classification accuracy for predicting strikes and balls achieved an area under the curve of 0.67. Kinematics that derived the highest % increase in mean square error included: trunk flexion excursion(4.06 %), pelvis obliquity at foot contact(4.03 %), and trunk rotation at hand separation(3.94 %). Pitchers who threw strikes had significantly less trunk rotation at hand separation(p = 0.004) and less trunk flexion at ball release(p = 0.003) compared to balls. The positive predictive value for determining a strike was within an acceptable range, while the negative predictive value suggests if a pitch was determined as a ball, the model was not adequate in its prediction. Kinematic measures of pelvis and trunk were crucial determinants for the pitch classifier sequence, suggesting pitcher kinematics at the proximal body segments may be useful in determining final pitch location. [ABSTRACT FROM AUTHOR]

Background: Improving our understanding of the situations and biomechanics that result in an anterior cruciate ligament (ACL) injury in basketball players may support the design of more effective programs to mitigate the risk of injury. Purpose: To (1) describe the mechanisms, situational patterns, and gross biomechanics (kinematics) of ACL injuries in professional basketball matches using video analysis and (2) document the distribution of ACL injuries according to player position, phase of the match, and location on the court. Study Design: Case series; Level of evidence, 4. Methods: A total of 38 ACL injuries in professional male European basketball leagues from the 2013-2014 to 2019-2020 seasons were identified. There were 36 (95%) injury videos analyzed for injury mechanisms and situational patterns, while biomechanical analysis was possible in 32 cases. Overall, 3 independent reviewers evaluated each video. Data according to player position (n = 38), phase of the match (n = 38), and location on the court (n = 36) were evaluated. Results: More injuries occurred while attacking (n = 25 [69%]) than defending (n = 11 [31%]). There was 1 (3%) direct contact injury, 21 (58%) indirect contact injuries, and 14 (39%) noncontact injuries. Most injuries (83%) occurred during 3 main situations: offensive cut (n = 17 [47%]), landing from a jump (n = 8 [22%]), and defensive cut (n = 5 [14%]). Injuries generally involved knee flexion (with minimal hip/trunk flexion and reduced plantarflexion) in the sagittal plane and knee valgus loading in most cases (75%). A similar number of injuries occurred during the first (53%) and second (47%) halves of the match, with a higher prevalence in the second (37%) and fourth (34%) quarters. Half of the injuries occurred during the first 10 minutes of effective playing time. More injuries occurred in guards (58%), and 73% of all injuries occurred in the scoring zone. Conclusion: Indirect contact was the main injury mechanism found in male professional basketball players. The offensive cut was the most common situational pattern. Biomechanical analysis confirmed a multiplanar mechanism, with knee loading in the sagittal plane accompanied by dynamic valgus. More injuries occurred in the first 10 minutes of a player's effective playing time, within the scoring zone, and among guards. [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]