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Objective: Women with hip-related pain (HRP) are underrepresented in the literature. As such, the movement strategies of women with HRP are not well understood. Therefore, the aim of the study was to compare the mechanical work completed by the lower limb joints during the single leg drop jump (SLDJ) in women with and without HRP. Methods: Female football players, aged 18-50 years, with and without HRP were eligible to participate. Twenty-three women with HRP and 13 controls participated. Biomechanical data on the SLDJ were collected using a three-dimensional motion capture system and force plates. Total lower limb work was calculated as well as the relative contributions of the hip, knee and ankle. Differences between group were assessed using t-tests. Results: The relative contribution to negative work done at the knee was significantly less in the women with HRP compared with the control group (mean difference -4.7%, 95%CI -9.1, -0.3; P=0.04). When comparing contributions across the three joints, the ankle provided the largest contribution to positive work for the HRP group (36.8%), with the hip being the largest contributor in the controls (35.4%). Conclusions: Women with HRP absorbed significantly less energy at the knee compared to healthy controls. The reason why women with HRP do not use a knee dominant strategy for absorbing energy during the SLDJ requires further scrutiny. Despite no difference in total positive work between groups, we did observe some subtle differences amongst the joints in the relative contributions to positive work done. The ankle was the dominant source of positive work during the SLDJ for women with HRP, whereas the hip was for controls. This strategy adopted by women with HRP may be an attempt to 'offload' the symptomatic hip. Clinical implications: The study demonstrates potential impairments that can be addressed in rehabilitation programs to normalise force attenuation and propulsive strategies in women with HRP. [ABSTRACT FROM AUTHOR]

Background: The relationship between hip/groin pain and hip range of motion (ROM) is unclear., Purpose: To explore the relationship between hip/groin pain and hip joint ROM and examine the influence of sex and cam morphology on this relationship., Study Design: Cross-sectional study; Level of evidence, 3., Methods: Included were 184 amateur soccer and Australian Rules football players (276 hips; 20% women; median age, 26 years; interquartile range, 24-30 years) with hip/groin pain >6 months and a positive flexion-adduction-internal-rotation (FADIR) test, and 50 matched asymptomatic control players (98 hips; 28% women, median age, 26 years; interquartile range, 23-31 years). Hip ROM measures were flexion, internal and external rotation at 90° of hip flexion, total rotation (internal and external), and bent-knee fall out (BKFO). Cam morphology was determined from anteroposterior pelvis or 45° Dunn radiographs, defined by an alpha angle ≥60°. Linear regression models with generalized estimating equations were used to examine the relationship between group (symptomatic and asymptomatic) and each ROM measure. Interaction terms (group × cam morphology or group × sex) were included to examine if relationships between group and hip ROM were influenced by cam morphology or sex. Where appropriate, models were adjusted for sex, age, and cam morphology., Results: An interaction between the relationship between group × cam and internal rotation ROM was found. Symptomatic players with cam morphology had lower internal rotation ROM than controls with cam morphology (adjusted mean difference [AMD] = -4.5°; 95% CI, -7.4° to -1.6°). Hip/groin pain was not associated with internal rotation ROM if cam morphology was absent. A significant interaction was also found for group × sex and BKFO and total rotation ROM. Symptomatic women had lower total rotation ROM than control women (AMD = -8.2°; 95% CI, -14.1° to -2.2°), but no difference was seen in men. BKFO range was lower in men with hip/groin pain compared with control men (AMD = 1.6 cm; 95% CI, 0.3-3.0 cm), but no difference was seen in women. Flexion and external rotation ROM did not differ between symptomatic and control hips., Conclusion: Cam morphology was an effect modifier of the relationship between hip/groin pain and internal rotation ROM. Sex-related differences were also observed in the relationship between hip/groin pain and hip ROM., Competing Interests: The authors declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© 2024 The Author(s).)

Objective: To investigate the effect of physical activity (PA) on development (motor, cognitive, social-emotional) in children 4-5 years old born <30 weeks' gestation, and to describe subgroups of children at risk of low PA in this cohort., Design: Longitudinal cohort study., Patients: 123 children born <30 weeks were recruited at birth and assessed between 4 and 5 years' corrected age., Main Outcome Measures: Development was assessed using the Movement Assessment Battery for Children, Second Edition (MABC-2), Little Developmental Coordination Disorder Questionnaire (L-DCDQ), Wechsler Preschool and Primary Scale of Intelligence (Fourth Edition; WPPSI-IV), and Strengths and Difficulties Questionnaire (SDQ). To measure PA, children wore an accelerometer and parents completed a diary for 7 days. Effects of PA on developmental outcomes, and associations between perinatal risk factors and PA, were estimated using linear regression., Results: More accelerometer-measured PA was associated with better MABC-2 aiming and catching scores (average standard score increase per hour increase in PA: 0.54, 95% CI 0.11, 0.96; p=0.013), and lower WPPSI-IV processing speed index scores (average composite score decrease per hour increase in PA: -2.36, 95% CI -4.19 to -0.53; p=0.012). Higher accelerometer-measured PA was associated with better SDQ prosocial scores. Major brain injury in the neonatal period was associated with less moderate-vigorous and less unstructured PA at 4-5 years., Conclusions: Higher levels of PA are associated with aspects of motor, cognitive and social-emotional skill development in children 4-5 years old born <30 weeks. Those with major brain injury in the neonatal period may be more vulnerable to low PA at preschool age., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Hop testing is widely used by clinicians to monitor rehabilitation and decide when to return to sport following anterior cruciate ligament reconstruction (ACLR); however, the trajectory of long-term hop performance has not been summarised., Objective: To investigate hop performance change over time after ACLR., Design: Systematic review with longitudinal meta-analysis., Data Sources: MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SPORTDiscus to 28 February 2023., Eligibility Criteria: Studies with ≥ 50 participants following primary ACLR, with mean participant age of 18-40 years, reporting a quantitative measure of hop performance (e.g. single forward hop distance). Results had to be reported for the ACLR limb and compared with (1) the contralateral limb (within person) and/or (2) an uninjured control limb (between person)., Results: We included 136 studies of 23,360 participants. Performance was similar across different hop tests, with steep initial improvements in within-person symmetry, tailing off after 18-24 months. ACLR limb hop performance was 5-10% lower compared with the contralateral limb at 1 year post-surgery, with largest deficits observed for vertical hop [87.0% contralateral limb (95% CI 85.3-88.8) compared with single forward hop 93.8% (95% CI 92.8-94.9)]. By 3-5 years, results were similar between ACLR and contralateral limbs. There were limited data for between-person comparisons (n = 17 studies). Exploratory analyses showed deficits in all forward hopping tests to be very strongly correlated with each other [e.g. single forward and triple hop rho = 0.96 (95% CI 0.90-0.99)], though there was discordance in the relationship between single forward hop and vertical hop performance [rho = 0.27 (95% CI - 0.53 to 0.79)]., Conclusions: Hop performance is comparable to the uninjured limb by 3-5 years post-ACLR, with the greatest deficits in within-person symmetry present in vertical and side hop tests. Assessment of hopping in multiple planes and comparison with uninjured controls, may provide the most complete evaluation of functional performance., (© 2024. The Author(s).)

Purpose: Hamstring spasticity is prevalent following neurological injury. The standardized assessment involves passive knee extension, in a position of 90° hip flexion. This creates passive insufficiency of the muscle and lacks ecological validity for walking, whereby the hip typically flexes to a maximum of 40° during swing phase, while the knee extends. This study compared assessment outcomes when completed in 40° and 90° hip flexion., Methods: The Modified Ashworth Scale and Modified Tardieu Scale, were performed on 35 adults with a neurological condition. Each participant was assessed by three assessors, resulting in 105 trials at 40° and 90°., Results: There was a significant increase in the proportion of trials rated as spastic using the Modified Ashworth Scale ( p =.012, phi=.27), and Modified Tardieu Scale ( p <.001, phi=.36), and the severity of spasticity using the Modified Ashworth Scale ( p <.001, effect size (ES)=.50), and Modified Tardieu Scale ( p <.001 ES=.47), at 90° hip flexion. The angle of reaction occurred 32° earlier at 90° hip flexion ( p <.001, ES = 1.61)., Conclusions: Completing hamstring assessments in 40° hip flexion may reduce the passive insufficiency and improve the ecological validity of assessment, for walking. This may assist in the selection of patients requiring intervention, when their goal relates to walking.

Background: Hip-related pain (HRP) affects young to middle-aged active adults and impacts physical activity, finances and quality of life. HRP includes conditions like femoroacetabular impingement syndrome and labral tears. Lateral hip muscle dysfunction and atrophy in HRP are more pronounced in advanced hip pathology, with limited evidence in younger populations. While MRI use for assessing hip muscle morphology is increasing, with automated deep-learning techniques showing promise, studies assessing their accuracy are limited. Therefore, we aimed to compare hip intramuscular fat infiltrate (MFI) and muscle volume, in individuals with and without HRP as well as assess the reliability and accuracy of automated machine-learning segmentations compared with human-generated segmentation., Methods: This cross-sectional study included sub-elite/amateur football players (Australian football and soccer) with a greater than 6-month history of HRP [n = 180, average age 28.32, (standard deviation 5.88) years, 19% female] and a control group of sub-elite/amateur football players without pain [n = 48, 28.89 (6.22) years, 29% female]. Muscle volume and MFI of gluteus maximus, medius, minimis and tensor fascia latae were assessed using MRI. Associations between muscle volume and group were explored using linear regression models, controlling for body mass index, age, sport and sex. A convolutional neural network (CNN) machine-learning approach was compared with human-performed muscle segmentations in a subset of participants (n = 52) using intraclass correlation coefficients and Sorensen-Dice index., Results: When considering adjusted estimates of muscle volume, there were significant differences observed between groups for gluteus medius (adjusted mean difference 23 858 mm 3 [95% confidence interval 7563, 40 137]; p = 0.004) and tensor fascia latae (6660 mm 3 [2440, 13 075]; p = 0.042). No differences were observed between groups for gluteus maximus (18 265 mm 3 [-21 209, 50 782]; p = 0.419) or minimus (3893 mm 3 [-2209, 9996]; p = 0.21). The CNN was trained for 30 000 iterations and assessed its accuracy and reliability on an independent testing dataset, achieving high segmentation accuracy (mean Sorenson-Dice index >0.900) and excellent muscle volume and MFI reliability (ICC 2,1  > 0.900). The CNN outperformed manual raters, who had slightly lower interrater accuracy (Sorensen-Dice index >0.800) and reliability (ICC 2,1  > 0.800)., Conclusions: The increased muscle volumes in the symptomatic group compared with controls could be associated with increased myofibrillar size, sarcoplasmic hypertrophy or both. These changes may facilitate greater muscular efficiency for a given load, enabling the athlete to maintain their normal level of function. In addition, the CNNs for muscle segmentation was more efficient and demonstrated excellent reliability in comparison to manual segmentations., (© 2024 The Author(s). Journal of Cachexia, Sarcopenia and Muscle published by Wiley Periodicals LLC.)

Background: Walking impairment is a common disability post acquired brain injury (ABI), with visually evident arm movement abnormality identified as negatively impacting a multitude of psychological factors. The International Classification of Functioning, Disability and Health (ICF) qualifiers scale has been used to subjectively assess arm movement abnormality, showing strong intra-rater and test-retest reliability, however, only moderate inter-rater reliability. This impacts clinical utility, limiting its use as a measurement tool. To both automate the analysis and overcome these errors, the primary aim of this study was to evaluate the ability of a novel two-level machine learning model to assess arm movement abnormality during walking in people with ABI., Methods: Frontal plane gait videos were used to train four networks with 50%, 75%, 90%, and 100% of participants (ABI: n = 42, healthy controls: n = 34) to automatically identify anatomical landmarks using DeepLabCut ™ and calculate two-dimensional kinematic joint angles. Assessment scores from three experienced neurorehabilitation clinicians were used with these joint angles to train random forest networks with nested cross-validation to predict assessor scores for all videos. Agreement between unseen participant (i.e. test group participants that were not used to train the model) predictions and each individual assessor's scores were compared using quadratic weighted kappa. One sample t-tests (to determine over/underprediction against clinician ratings) and one-way ANOVA (to determine differences between networks) were applied to the four networks., Results: The machine learning predictions have similar agreement to experienced human assessors, with no statistically significant (p < 0.05) difference for any match contingency. There was no statistically significant difference between the predictions from the four networks (F = 0.119; p = 0.949). The four networks did however under-predict scores with small effect sizes (p range = 0.007 to 0.040; Cohen's d range = 0.156 to 0.217)., Conclusions: This study demonstrated that machine learning can perform similarly to experienced clinicians when subjectively assessing arm movement abnormality in people with ABI. The relatively small sample size may have resulted in under-prediction of some scores, albeit with small effect sizes. Studies with larger sample sizes that objectively and automatically assess dynamic movement in both local and telerehabilitation assessments, for example using smartphones and edge-based machine learning, to reduce measurement error and healthcare access inequality are needed., (© 2024. The Author(s).)

Objectives: To investigate associations between lateral hip muscle size/intramuscular fat infiltration (MFI) and hip strength in active young adults with longstanding hip/groin pain., Design: Cross-sectional study., Setting: University/Clinical., Participants: Sub-elite soccer and Australian Football players (n = 180; 37 female) with long standing hip/groin pain., Main Outcome Measures: Muscle size (volume) and MFI of gluteus maximus, medius, and minimis, and tensor fascia latae (TFL) were assessed using magnetic resonance imaging. Isometric hip strength was measured with handheld dynamometry. Associations between muscle size/MFI were assessed using linear regression models, adjusted for body mass index and age, with sex-specific interactions., Results: Positive associations were identified between lateral hip muscle volume and hip muscle strength, particularly for gluteus maximus and gluteus minimus volume. For all muscles, hip abduction was associated with an increase in strength by up to 0.69 N (R 2 ranging from 0.29 to 0.39). These relationships were consistent across sexes with no sex interactions observed. No associations were found between MFI and strength measures., Conclusion: Greater lateral hip muscle volumes are associated with greater hip strength in active young adults with long standing hip/groin pain, irrespective of sex. Gluteus maximus and minimus volume showed the most consistent relationships with hip strength across multiple directions., Competing Interests: Declaration of competing interest None. All authors declare that they have no competing interests to disclose., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To investigate whether tailoring the speed of the Modified Tardieu Scale to reflect an individual's joint angular velocity during walking influences spasticity assessment outcomes., Design: Observational trial., Setting: Inpatient and outpatient neurological hospital department., Subjects: Ninety adults with lower-limb spasticity., Interventions: N/A., Main Measures: The Modified Tardieu Scale was used to assess the gastrocnemius, soleus, hamstrings and quadriceps. The V1 (slow) and V3 (fast) movements were completed as per standardised testing. Two additional assessments were completed, reflecting joint angular velocities during walking based on (i) a healthy control database (controlled velocity) and (ii) the individual's real-time joint angular velocities during walking (matched velocity). The agreement was compared using Cohen's and Weighted Kappa statistics, sensitivity and specificity., Results: There was poor agreement when rating trials as spastic or not spastic at the ankle joint (Cohen's Kappa = 0.01-0.17). Trials were classified as spastic during V3 and not spastic during the controlled conditions in 81.6-85.1% of trials when compared to stance phase dorsiflexion angular velocities and 48.0-56.4% when compared to swing phase dorsiflexion angular velocities. The severity of muscle reaction demonstrated poor agreement at the ankle (Weighted Kappa = 0.01-0.28). At the knee, there was a moderate-excellent agreement between the V3 and controlled conditions when rating a trial as spastic or not spastic (Cohen's Kappa = 0.66-0.84) and excellent agreement when comparing severity (Weighted Kappa = 0.73-0.94)., Conclusion: The speed of assessment impacted spasticity outcomes. It is possible that the standardised protocol may overestimate the impact spasticity has on walking, especially at the ankle., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

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

Background: Femoroacetabular impingement (FAI) syndrome is considered a motion-related condition. Little is known about the influence of symptom severity and cam morphology on hip biomechanics for individuals with FAI syndrome., Research Question: Are hip biomechanics during running associated with symptom severity or cam morphology size in male football players with FAI syndrome?, Methods: Forty-nine male, sub-elite football (soccer or Australian football) players (mean age= 26 years) with FAI syndrome completed the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS) and underwent radiographic evaluation. Biomechanical data were collected during overground running (3-3.5 m∙s -1 ) using three-dimensional motion capture technology and an embedded force plate. Various discrete hip angles and impulses of joint moments were analysed during the stance phase. Linear regression models investigated associations between running biomechanics data (dependent variables) and iHOT-33 and HAGOS scores and cam morphology size (independent variables)., Results: Hip joint angles during running were not associated with symptom severity in football players with FAI syndrome. A positive association was found between the impulse of the hip external rotation moment and HAGOS-Sport scores, such that a smaller impulse magnitude occurred with a lower HAGOS-Sport score (0.026 *10 -2 [95%CI <0.001 *10 -2 to 0.051 *10 -2 ], P = 0.048). Larger cam morphology was associated with a greater peak hip adduction angle at midstance (0.073 [95%CI 0.002-0.145], P = 0.045)., Significance: Hip biomechanics during running did not display strong associations with symptom severity or cam morphology size in male football players with FAI syndrome who were still participating in training and match play. Future studies might consider investigating associations during tasks that utilise end range hip joint motion or require greater muscle forces., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Prof Kay Crossley reports financial support was provided by National Health and Medical Research Council of Australia. Dr Joanne Kemp reports financial support was provided by National Health and Medical Research Council of Australia. Dr Mark Scholes reports financial support was provided by Australian Government Research Training Programme. Dr Matthew King reports financial support was provided by Australian Government Research Training Programme. Dr Joshua Heerey reports financial support was provided by Australian Government Research Training Programme. Dr Benjamin Mentiplay serves on the editorial board at Gait and Posture., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objectives: Explore associations between peak hip strength in football players with hip/groin pain and healthy controls., Design: Cross-sectional study., Methods: Male and female sub-elite football players (soccer and Australian football) with hip/groin pain >6-month duration and players without hip/groin pain were recruited across Melbourne and Brisbane, Australia. Demographic information and two questionnaires; the Copenhagen Hip and Groin Outcome Score and the International Hip Outcome Tool 33 were collected. Hand-held dynamometry was used to measure isometric hip strength for flexion, extension, abduction, adduction, internal rotation, and external rotation. Linear mixed effects models were used to compare strength measures between groups., Results: 190 football players with hip/groin pain (mean ± standard deviation age, 27.8 ± 6.3 years) and 64 controls (age, 27.3 ± 5.6 years) were included in this study. Of these, 291 symptomatic limbs and 128 control limbs were used for analyses. Symptomatic players had lower peak hip adduction (adjusted mean difference = -0.18: 95 % confidence interval -0.27 to -0.08, P : 0.001), external rotation (-0.06: 95 % confidence interval -0.09 to -0.02, P : 0.003), and internal rotation strength (-0.06: 95 % confidence interval -0.10 to -0.03, P : 0.001) compared to controls. A sport-specific interaction was observed for hip abduction strength. When separated by football code, abduction strength was lower in symptomatic Australian football players compared to their same sport peers (-0.20: 95 % confidence interval -0.33 to -0.06, P : 0.004), but not in symptomatic soccer players (-0.05: 95 % confidence interval -0.15 to 0.06, P : 0.382)., Conclusions: Hip adduction, internal rotation, and external rotation strength appears lower in football players with hip/groin pain independent of sex and football code. Hip abduction strength was lower in symptomatic Australian football players but not in soccer players., Competing Interests: Declaration of interest statement None., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: We compared body mass index (BMI), body fat, and skeletal muscle mass between (1) a mixed-sex nonathletic cohort of people with patellofemoral pain (PFP) and pain-free people, and (2) a nonathletic cohort of people with PFP and pain-free people subgrouped by sex (i.e., men and women with PFP vs. pain-free men and women)., Methods: This cross-sectional study included 114 people with PFP (71 women, 43 men) and 54 pain-free controls (32 women, 22 men). All participants attended a single testing session to assess body composition measures, which included BMI, percentage of body fat (%BF Bioimpedance ), and skeletal muscle mass (both assessed by bioelectrical impedance analysis), and percentage of body fat (%BF Skinfold ) (assessed by skinfold caliper analysis). A one-way univariate analysis of covariance (age and physical activity levels as covariates) was used to compare body composition measures between groups (i.e., PFP vs. pain-free group; women with PFP vs. pain-free women; men with PFP vs. pain-free men)., Results: Women with PFP presented significantly higher BMI, %BF Bioimpedance , and %BF Skinfold , and lower skeletal muscle mass compared to pain-free women (p ≤ 0.04; effect size : ‒0.47 to 0.85). Men with PFP and men and women combined had no differences in BMI, %BF Bioimpedance , %BF Skinfold , and skeletal muscle mass compared to their respective pain-free groups (p > 0.05)., Conclusion: Our findings indicate that BMI and body composition measures should be considered as part of the evaluation and management of people with PFP, especially in women, who have demonstrated higher BMI and body fat and lower skeletal muscle mass compared to pain-free controls. Future studies should not assess body composition measures in a mixed-sex population without distinguishing men participants from women participants., (Copyright © 2021. Production and hosting by Elsevier B.V.)

Background: Altered hip and thigh muscle activity have been observed across a spectrum of articular hip pathologies, including hip osteoarthritis, femoroacetabular impingement syndrome, and labral pathology. No systematic reviews have examined muscle activity associated with hip pathology and hip-related pain across the life span. A greater understanding of impairments in hip and thigh muscle activity during functional tasks may assist in the development of targeted treatment strategies., Methods: We conducted a systematic review using the PRISMA guidelines. A literature search was performed in five databases (MEDLINE, CINAHL, EMBASE, Sports Discuss, and PsychINFO). Studies were included that (i) investigated people with hip-related pain (femoroacetabular impingement syndrome, labral tears) or hip osteoarthritis; and (ii) reported on muscle activity using electromyography of hip and thigh muscles during functional tasks such as walking, stepping, squatting, or lunging. Two independent reviewers performed data extraction and assessed risk of bias using a modified version of the Downs and Black checklist., Results: Non-pooled data demonstrated a limited level of evidence. Overall, differences in muscle activity appeared to be more prevalent in people with more advanced hip pathology., Conclusions: We found that impairments in muscle activity in those with intra-articular hip pathology measured using electromyography were variable but appeared to be greater in severe hip pathology (e.g., hip OA)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

Purpose: This study aimed to (a) investigate the proportion of overweight/obesity in a cohort of young adults with patellofemoral pain (PFP) and (b) explore the association of body mass index (BMI), body fat, and lean mass with functional capacity and hip and knee strength in people with PFP., Methods: We included a mixed-sex sample of young adults (18-35 years old) with PFP (n = 100). Measurements for BMI, percentage of body fat, and lean mass (assessed by bioelectrical impedance) were obtained. Functional capacity was assessed by the Anterior Knee Pain Scale, plank test, and single-leg hop test. Strength of the knee extensors, knee flexors, and hip abductors was evaluated isometrically using an isokinetic dynamometer. The proportion of overweight/obesity was calculated based on BMI. The association between BMI, body fat, and lean mass and functional capacity and strength was investigated using partial correlations, followed by hierarchical regression analysis, adjusted for covariates (sex, bilateral pain, and current pain level)., Results: A total of 38% of our cohort had their BMI categorized as overweight/obese. Higher BMI was associated with poor functional capacity (ΔR 2  = 0.06-0.12, p ≤ 0.001) and with knee flexion strength only (ΔR 2  = 0.04, p = 0.030). Higher body fat was associated with poor functional capacity (ΔR 2  = 0.05-0.15, p ≤ 0.015) and reduced strength (ΔR 2  = 0.15-0.23, p < 0.001). Lower lean mass was associated with poor functional capacity (ΔR 2  = 0.04-0.13, p ≤ 0.032) and reduced strength (ΔR 2  = 0.29- 0.31, p < 0.001)., Conclusion: BMI, body fat, and lean mass should be considered in the assessment and management of young people with PFP because it may be detrimental to function and strength., (Copyright © 2021. Production and hosting by Elsevier B.V.)

Introduction: Running is one of the most popular recreational activities worldwide, due to its low cost and accessibility. However, little is known about the impact of running on knee joint health in runners with and without a history of knee surgery. The primary aim of this longitudinal cohort study is to compare knee joint structural features on MRI and knee symptoms at baseline and 4-year follow-up in runners with and without a history of knee surgery. Secondary aims are to explore the relationships between training load exposures (volume and/or intensity) and changes in knee joint structure and symptoms over 4 years; explore the relationship between baseline running biomechanics, and changes in knee joint structure and symptoms over 4 years. In addition, we will explore whether additional variables confound, modify or mediate these associations, including sex, baseline lower-limb functional performance, knee muscle strength, psychological and sociodemographic factors., Methods and Analysis: A convenience sample of at least 200 runners (sex/gender balanced) with (n=100) and without (n=100) a history of knee surgery will be recruited. Primary outcomes will be knee joint health (MRI) and knee symptoms (baseline; 4 years). Exposure variables for secondary outcomes include training load exposure, obtained daily throughout the study from wearable devices and three-dimensional running biomechanics (baseline). Additional variables include lower limb functional performance, knee extensor and flexor muscle strength, biomarkers, psychological and sociodemographic factors (baseline). Knowledge and beliefs about osteoarthritis will be obtained through predefined questions and semi-structured interviews with a subset of participants. Multivariable logistic and linear regression models, adjusting for potential confounding factors, will explore changes in knee joint structural features and symptoms, and the influence of potential modifiers and mediators., Ethics and Dissemination: Approved by the La Trobe University Ethics Committee (HEC-19524). Findings will be disseminated to stakeholders, peer-review journals and conferences., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The general health benefits of running are well-established, yet concern exists regarding the development and progression of osteoarthritis., Aim: To systematically review the immediate (within 20 min) and delayed (20 min-48 h) effect of running on hip and knee cartilage, as assessed using magnetic resonance imaging (MRI)., Method: Studies using MRI to measure change in hip or knee cartilage within 48 h pre- and post-running were identified. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Percentage change in cartilage outcomes were estimated using random-effects meta-analysis. Certainty of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation tool., Results: Twenty-four studies were included, evaluating 446 knees only. One third of studies were low risk of bias. Knee cartilage thickness and volume decreased immediately after running, with declines ranging from 3.3% (95% confidence interval [CI]: 2.6%, 4.1%) for weight-bearing femoral cartilage volume to 4.9% (95% CI: 4.43.6%, 6.2%) for patellar cartilage volume. T1ρ and T2 relaxation times were also reduced immediately after running, with the largest decline being 13.1% (95% CI: -14.4%, -11.7%) in femoral trochlear cartilage. Tibiofemoral cartilage T2 relaxation times recovered to baseline levels within 91 min. Existing cartilage defects were unchanged within 48 h post-run., Conclusions: There is very low certainty evidence that running immediately decreases the thickness, volume, and relaxation times of patellofemoral and tibiofemoral cartilage. Hip cartilage changes are unknown, but knee changes are small and appear transient suggesting that a single bout of running is not detrimental to knee cartilage., Competing Interests: Conflicts of interest The authors declare they have no competing interests., (Copyright © 2022 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Background: Developing context-specific, evidence-informed, and implementable injury-prevention programs is challenging. Women playing in the elite Australian Football League for Women are at high risk of serious knee injuries, and no specific injury-prevention program exists. The objective of the study was to describe the collaborative process used to create a context-specific injury-prevention program., Methods: A previously used intervention-development process was modified to incorporate a partnership with the sport's governing organization and focus on engaging program implementers. The Reach Effectiveness Adoption Implementation and Maintenance (RE-AIM) Sports Setting Matrix guided program development and implementation strategies., Results: The 7-step process, aligned with the RE-AIM Sports Setting Matrix, was applied to develop the injury-prevention program and was titled Prep to Play PRO. The steps were: (Step 1) gaining organizational support and establishing a project partnership; (Step 2) using research evidence and clinical experience; (Step 3) consulting content and context experts; (Step 4) engaging the organization, experts, program implementers, and end-users to concreate the intervention and develop implementation strategies; (Step 5) testing the intervention acceptability and feasibility; (Step 6) evaluating the intervention and implementation strategies against theory; and (Step 7) obtaining feedback from early implementers and end-users., Conclusion: Engaging critical stakeholders at multiple ecological levels (organization, team, and athlete) throughout program development and implementation planning support real-world use. The processes and activities described can guide future sports injury-prevention program development and implementation., (Copyright © 2021. Production and hosting by Elsevier B.V.)

Background: It is unknown if football players with femoroacetabular impingement (FAI) syndrome report worse burden than those with other causes of hip/groin pain, and to what extent this is mediated by cartilage defects and labral tears., Hypothesis: Football players with FAI syndrome would report worse burden than other symptomatic players, with the effect partially mediated by cartilage defects and/or labral tears., Study Design: Cross-sectional study., Level of Evidence: Level 4., Methods: Football (soccer and Australian football) players (n = 165; 35 women) with hip/groin pain (≥6 months and positive flexion-adduction-internal rotation test) were recruited. Participants completed 2 patient-reported outcome measures (PROMs; the International Hip Outcome Tool-33 [iHOT-33] and Copenhagen Hip and Groin Outcome Score [HAGOS]) and underwent hip radiographs and magnetic resonance imaging (MRI). FAI syndrome was determined to be present when cam and/or pincer morphology were present. Cartilage defects and labral tears were graded as present or absent using MRI. Linear regression models investigated relationships between FAI syndrome (dichotomous independent variable) and PROM scores (dependent variables). Mediation analyses investigated the effect of cartilage defects and labral tears on these relationships., Results: FAI syndrome was not related to PROM scores (unadjusted b values ranged from -4.693 ( P = 0.23) to 0.337 ( P = 0.93)) and cartilage defects and/or labral tears did not mediate its effect ( P = 0.22-0.97)., Conclusion: Football players with FAI syndrome did not report worse burden than those with other causes of hip/groin pain. Cartilage defects and/or labral tears did not explain the effect of FAI syndrome on reported burden., Clinical Relevance: FAI syndrome, cartilage defects, and labral tears were prevalent but unrelated to reported burden in symptomatic football players.

Purpose: To determine which potential contributing factors are associated with upper limb associated reaction (AR) expression in individuals with acquired brain injury (ABI)., Methods: Forty-two participants underwent three-dimensional motion analysis at self-selected walking speed to generate the AR outcome measure, quantifying their upper limb kinematic deviation compared to healthy controls. Clinical assessment included: upper and lower limb hypertonicity, spasticity and strength, balance, dynamic walking stability, arm and leg function, anxiety, arm pain/discomfort, and fear of falling., Results: Significant, moderate-to-strong correlations ( r  = 0.42-0.74, p  < 0.05) existed between upper limb ARs and both hypertonicity and spasticity of the upper limb muscles and the knee extensors. Significant, moderate correlations to ARs ( r  = 0.42-0.59, p  < 0.05) existed for balance, dynamic stability, upper limb strength, and arm function. The severity of AR was significantly different between those with and without hypertonicity of the four tested upper limb muscles, elbow and long finger flexor spasticity, knee extensor spasticity, and reduced dynamic stability ( p  < 0.05; effect sizes ≥0.80). However, these contributing factors were not present in all participants., Conclusions: Associated reactions are complex and multi-factorial. There were several significant correlations indicating that factors may influence AR severity. While positive upper motor neuron syndrome features should be prioritised for clinical assessment, these factors are not prerequisites for ARs.IMPLICATIONS FOR REHABILITATIONUpper limb associated reactions are a complex and multi-factorial phenomenon.Upper limb muscle hypertonicity and spasticity should be prioritised for assessment; however, they are not prerequisites for associated reactions.Hypertonicity and spasticity should be differentiated as they may have differing relationships to associated reactions.Knee extensor hypertonicity and spasticity, postural stability, upper limb strength, and arm function may also be contributing factors to consider.

Objective: The objective of this study was to determine whether school readiness differs between children born <30 weeks' gestation who are classified as at risk for developmental coordination disorder (DCD) and those who are not., Methods: This study was a prospective cohort study of children born <30 weeks' gestation. Children were classified as at risk for DCD at a corrected age of 4 to 5 years if they scored <16th centile on the Movement Assessment Battery for Children-Second Edition (MABC-2), had a full scale IQ score of ≥80 on the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition (WPPSI-IV), and had no cerebral palsy. Children were assessed on 4 school readiness domains: (1) health/physical development [Physical Health domain of Pediatric Quality of Life Inventory (PedsQL), Pediatric Evaluation of Disability Inventory Computer Adaptive Test, and Little Developmental Coordination Disorder Questionnaire], (2) social-emotional development (Strengths and Difficulties Questionnaire and PedsQL psychosocial domains), (3) cognitive skills/general knowledge (WPPSI-IV), and (4) language skills (WPPSI-IV)., Results: Of 123 children assessed, 16 were ineligible (IQ < 80 or cerebral palsy: n = 15; incomplete MABC-2: n = 1); 28 of 107 (26%) eligible children were at risk for DCD. Children at risk for DCD had poorer performance on all school readiness domains, with group differences of more than 0.4 SD in health/physical development, social-emotional development, and language skills and up to 0.8 SD for cognitive skills/general knowledge compared with those not at risk of DCD., Conclusion: Being at risk for DCD in children born <30 weeks' gestation is associated with challenges in multiple school readiness domains, not only the health/physical domain., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: i) Compare functional task performance between football players with and without hip/groin pain. ii) Explore the relationship, and sex-specific effects, between functional tasks and the Copenhagen Hip and Groin Outcome Score (HAGOS) in players with hip/groin pain., Design: Cross-sectional., Setting: Laboratory., Participants: 183 (38 women) football players with a self-reported history of >6months of non-time-loss hip/groin pain and a positive flexion-adduction-internal rotation test, and 61 (14 women) asymptomatic players., Main Outcome: Participants completed the hop-for-distance (HFD), one leg rise (OLR), side bridge (SB) endurance, and HAGOS. Study aims were assessed using linear models, controlling for body mass index and age, incorporating sex-specific interaction terms., Results: Players with hip/groin pain could not hop as far (adjusted mean difference: -9 cm, 95% CI: -15 cm to -2cm, P=0.012) and completed fewer OLR repetitions (adjusted mean difference -7, 95% confidence interval -11 to -3 repetitions, P=0.001) compared to asymptomatic players. Symptomatic women, but not symptomatic men, with worse HAGOS scores had lower SB endurance. Independent of sex, football players with worse HAGOS scores could not hop as far and completed fewer OLR repetitions., Conclusion: Football players with hip/groin pain demonstrated deficits in HFD and OLR with the performance of these tasks associated with their HAGOS results. The study identifies potential impairments that can be targeted as a component of rehabilitation programs for football players with hip/groin pain., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Cam morphology size and location might affect the severity of reported burden in people with femoroacetabular impingement (FAI) syndrome. We investigated the relationship between cam morphology size (i.e., alpha angle) and self-reported hip/groin burden (i.e., scores for the International Hip Outcome Tool-33 (iHOT-33) and Copenhagen Hip and Groin Outcome Score (HAGOS)), examined separately for the anteroposterior pelvis (AP) and Dunn 45° radiographs in football players with FAI syndrome. In total, 118 (12 women) subelite football (soccer or Australian football) players with FAI syndrome with cam morphology (alpha angle ≥60°) participated. One blinded assessor quantified superior and anterosuperior cam morphology size by measuring alpha angles for the AP and Dunn 45° radiographs, respectively. Linear regression models investigated relationships between alpha angle (continuous independent variable, separately measured for the AP and Dunn 45° radiographs) and iHOT-33 and HAGOS scores (dependent variables). Larger anterosuperior cam morphology (seen on the Dunn 45° radiograph) was associated with lower (i.e., worse) scores for the iHOT-Total, iHOT-Symptoms, iHOT-Job, and iHOT-Social subscales (unadjusted estimate range -0.553 to -0.319 [95% confidence interval -0.900 to -0.037], p = 0.002 to 0.027), but not the iHOT-Sport (p = 0.459) nor any HAGOS scores (p = 0.110 to 0.802). Superior cam morphology size (measured using the AP radiograph) was not associated with any iHOT-33 or HAGOS scores (p = 0.085 to 0.975). Larger anterosuperior cam morphology may be more relevant to pain and symptoms in football players with FAI syndrome than superior cam morphology, warranting investigation of its effects on reported burden and hip disease over time., (© 2022 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.)

Objectives: The purpose of this study was to investigate the effectiveness of an isometric neck strengthening program to improve isometric neck strength in elite women's football-code athletes., Design: Randomised controlled trial., Methods: Elite female soccer (n = 10) and Australian football (n = 30) players were randomised into either a control (n = 20) or experimental (n = 20) group for a 12-week intervention study during their respective seasons. While both groups undertook their prescribed strength and conditioning programs, the experimental group also performed isometric neck strengthening exercises three times per week prior to training. Isometric neck strength of the extensors, flexors, lateral flexors, and rotators were assessed pre, mid (Week 7), and post (Week 13) intervention with a hand-held dynamometer during early to mid-competition season. A mixed design analysis of variance was performed for statistical analysis., Results: No significant group-by-time interactions in isometric neck strength were observed. All strength variables displayed a significant change over time throughout the 12-week period (p < 0.05). No significant between group differences in isometric neck strength variables were observed except for lateral left flexion (F(1, 38) =5.064, p = 0.030, η 2 p  = 0.117)., Conclusions: The addition of isometric neck strengthening exercises did not improve neck strength beyond a standard strength and conditioning program for elite women's football-code athletes. While this specific program may not improve neck strength in elite women's football-code athletes, further investigation is needed to determine whether sport-specific neck strength exercises may improve neck strength or if lower-level competition athletes may still benefit from an isometric neck strengthening program., (Copyright © 2021 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Background: Hip muscle weakness and altered hip biomechanics during walking are often observed in people with femoroacetabular impingement syndrome, although little is known about biomechanics during higher impact tasks. The aim of our study was to explore relationships between hip muscle strength and hip biomechanics during running in people with femoroacetabular impingement syndrome, including exploring sex as an effect-modifier of this relationship., Methods: Forty-two adults with unilateral femoroacetabular impingement syndrome (20 females; age 18-50 years; alpha angle ≥60°) completed assessments of hip muscle strength and hip biomechanics during running. Strength was assessed using a hand-held dynamometer for the hip flexors, extensors, abductors, adductors, internal rotators, and external rotators. Hip biomechanics were assessed during overground running (3-3.5 m/s) using three-dimensional motion capture and a force plate. Linear models assessed the relationships between hip strength and hip biomechanics of the symptomatic limb, controlling for body mass and running velocity along with an interaction term (strength*sex)., Findings: A significant negative relationship was observed between hip external rotator strength and hip frontal plane range of motion (i.e., excursion), independent of sex (estimate = -0.039, 95%CI -0.071 to -0.008, P = 0.02). Four sex-specific interactions were observed, with a significant positive relationship between hip external rotator strength and peak hip extension moment in women (estimate = -0.413, 95%CI -0.713 to -0.114, P = 0.01) but not in men., Interpretation: We found significant relationships between hip external rotator strength and stance phase running biomechanics, providing further understanding on two impaired physical measures that may inform exercise-based management strategies in femoroacetabular impingement syndrome., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Children born very preterm (< 32 weeks' gestation) are at greater risk of motor impairment and executive/attentional dysfunctions than term-born children; however, little is known about how functional tasks, including walking, may be affected by very preterm birth., Research Question: How does the gait pattern of preschool-age children born < 30 weeks compare with term-born controls under a variety of walking conditions?, Methods: In this prospective cohort study, children born < 30 weeks and at term were assessed at 4.5-5 years' corrected age, blinded to birth group. Four walking conditions were assessed using the GAITRite® system: preferred speed, cognitive dual-task, motor dual-task, and tandem walking. Gait variables analysed included speed, cadence, step length, step time, base of support (BOS), and single and double support time. Spatiotemporal variables were compared between groups using linear regression, adjusting for lower-limb length, corrected age at assessment, and number of trials., Results: 224 children (112 < 30 weeks and 112 term-born) were assessed. Gait variables of children born < 30 weeks did not differ from their term-born peers when walking at their preferred speed, except for higher BOS variability (mean difference [MD] = 0.19 cm, 95% confidence interval [CI] 0.10, 0.27, p < 0.001). Under the motor dual-task condition, children born < 30 weeks walked faster (MD= 3.06 cm/s, 95% CI 0.14, 5.97, p = 0.040), with a longer step length (MD= 1.10 cm, 95%CI 0.19, 2.01, p = 0.018), and a wider BOS (MD= 0.37 cm, 95%CI 0.06, 0.67, p = 0.019). In cognitive dual-task and tandem conditions, children born < 30 weeks walked with a wider BOS compared with term-born peers (MD= 0.43 cm, 95%CI 0.05, 0.81, p = 0.028; and MD= 0.30 cm, 95%CI 0.09, 0.51, p = 0.005, respectively)., Significance: This research highlights the need to consider the walking performance of preschool-age children born < 30 weeks under challenging conditions, such as dual-task or tandem walking, when assessing gait patterns and planning interventions., (Copyright © 2021. Published by Elsevier B.V.)

Upper limb kinematic abnormalities are prevalent in people with acquired brain injury (ABI). We examined if the Microsoft Kinect for Xbox One (Kinect) reliably (test-retest) and validly (concurrent) quantifies upper limb kinematics, and accurately classifies abnormalities (sensitivity/specificity), in an ABI cohort when compared to three-dimensional motion analysis (3DMA) and a subjective rating scale. We compared 42 adults with ABI to 36 healthy control (HC) participants. Walking trials were recorded by 3DMA and Kinect at self-selected (SSWS) and fast (FWS) walking speeds. When classifying abnormalities for 3DMA and Kinect, a 95% reference range (based on HC data) was calculated using the Kinematic Deviation Score worst axis (KDSw); values outside of this range were classified abnormal. Scores ≥ 2 in the subjective rating scale, based on International Classification of Functioning, Disability and Health Framework's Qualifiers Scale, were considered abnormal. Test-retest reliability and concurrent validity were determined using intra-class correlation coefficient (Absolute ICC 2,1 ) and Pearson's or Spearman's correlation respectively. Fisher's Exact Test was conducted to determine sensitivity and specificity between each combination of the two methods. Strong test-retest reliability was observed for 3DMA (median(IQR) ICC:0.86(0.85-0.90)). Kinect showed overall strong SSWS test-retest reliability (ICC:0.87(0.84-0.91)) and moderate FWS test-retest reliability (ICC:0.61(0.56-0.65)). Concurrent validity between 3DMA and Kinect was overall moderate. Sensitivity and specificity between 3DMA, Kinect and subjective scores were overall modest. Our results suggest caution should be used if implementing Kinect as its validity is modest against criterion-reference 3DMA; however, given its reliability and similar sensitivity/specificity to 3DMA further responsiveness research is warranted., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Objective: Examine whether football players with hip and/or groin (hip/groin) pain have impaired running biomechanics when compared to pain-free players, analysing men and women independently., Design: Cross-sectional., Setting: Biomechanics laboratory., Participants: Seventy-eight (62 men, 16 women) football players with >6months of hip/groin pain and a positive flexion-adduction-internal rotation test and 38 (25 men, 13 women) asymptomatic players., Main Outcome Measures: Pelvis angles and hip, knee, and ankle joint angles and moments were analysed during the stance phase of overground running at 3-3.5 m⋅s -1 . Continuous joint angle and moment data were compared between symptomatic and asymptomatic football players of the same sex using statistical parametric mapping. Joint moment impulses (area under the curve) were compared between groups using linear regression models., Results: Symptomatic football players did not display significant differences in pelvis angles or lower-limb joint angles, moments, or moment impulses during the stance phase of running, when compared to asymptomatic players of the same sex., Conclusion: Our large sample of football players with hip/groin pain who were still participating in competitive sport displayed similar running biomechanics to asymptomatic players. Impaired running biomechanics might exist in people with worse hip/groin pain, warranting future investigation., Competing Interests: Declaration of competing interest The authors declare that they have no financial involvement or affiliations with any organizations or bodies with direct financial interest in the content discussed in this article., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: The International Hip Outcome Tool-33 (iHOT-33) was developed to evaluate patients seeking surgery for hip and/or groin (hip/groin) pain and may not be appropriate for those seeking nonsurgical treatment., Purpose: To evaluate the psychometric properties of the iHOT-33 total (iHOT-Total) score and all subscale scores in adults with hip/groin pain who were not seeking surgery., Study Design: Cohort study (diagnosis); Level of evidence, 3., Methods: Patients with hip/groin pain who were not seeking surgery were recruited from 2 ongoing studies in Australia. Semistructured one-on-one interviews assessed content validity. Construct validity was assessed by testing hypothesized correlations between iHOT-33 and Copenhagen Hip and Groin Outcome Score (HAGOS) subscale scores. Test-retest reliability was assessed in patients not undertaking treatment and who reported "no change" in their Global Rating of Change (GROC) score at 6-month follow-up. Scores were reliable at group and individual levels if intraclass correlation coefficients (ICCs) were ≥0.80 and ≥0.90, respectively. Scores were responsive if Spearman rank correlations (ρ) between the change in the iHOT-33 score and the GROC score were ≥0.40., Results: In total, 278 patients with hip/groin pain (93 women; mean age, 31 years) and 55 pain-free control participants (14 women; mean age, 29 years) were recruited. The iHOT-33 demonstrated acceptable content validity. Construct validity was acceptable, with all hypothesized strong positive correlations between iHOT-33 and HAGOS subscale scores confirmed ( r range, 0.60-0.76; P < .001), except for one correlation between the iHOT-Sport and HAGOS-Sport ( r = .058; P < .001). All scores were reliable at the group level, except for the iHOT-33 job subscale (iHOT-Job) (ICC range, 0.78-0.88 [95% CI, 0.60-0.93]). None of the subscales met the criteria for adequate reliability for use at the individual level (all ICCs <0.90). Minimal detectable change values (group level) ranged from 2.3 to 3.7 (95% CI, 1.7-5.0). All iHOT-33 subscale scores were responsive (ρ range, 0.40-0.58; P ≤ .001), except for the iHOT-Job in patients not undertaking treatment (ρ = 0.27; P = .001)., Conclusion: All iHOT-33 subscale scores were valid for use in patients with hip/groin pain who were not seeking surgery. Acceptable test-retest reliability was found for all subscale scores at the group level, except the iHOT-Job. All subscale scores, excluding the iHOT-Job, were responsive, regardless of undertaking physical therapist-led treatment or no treatment.

Objective: Children born <30 weeks of gestation have more motor impairment than do children born at term (37-42 weeks gestation), but reported outcomes have largely focused on cerebral palsy and developmental coordination disorder. The aim of this study was to compare muscle strength, motor skills, and physical activity (PA) of preschool-aged children born <30 weeks with those born at term., Methods: In this cohort study, 123 children born <30 weeks and 128 born at term were assessed. Children were aged ≥4 years, 0 months and <6 years, 0 months' corrected age at the time of the assessment. Outcomes included grip strength (kg), Movement Assessment Battery for Children 2nd edition (MABC-2), Little Developmental Coordination Disorder Questionnaire, accelerometer-measured PA, and a parent-completed PA diary. Linear regression and mixed effects models were used to examine differences between children born <30 weeks and those born at term., Results: Children born <30 weeks had poorer grip strength (preferred hand; mean difference [95% CI] -0.60 kg [-1.04 to -0.15]) and poorer motor competence (Movement Assessment Battery for Children 2nd edition standard score mean difference -2.17 [-3.07 to -1.27]; Little Developmental Coordination Disorder Questionnaire total score mean difference -5.5 [-9.2 to -2.8]) than term-born children. Children born <30 weeks also completed fewer minutes of accelerometer-measured PA (mean difference -41 minutes [-62 to -20]), more minutes of accelerometer-measured stationary behavior (mean difference 33 minutes [12 to 54]), and more minutes of parent-reported screen time (mean difference 21 minutes [10 to 32]) per day., Conclusion: Preschool-aged children born <30 weeks had poorer muscle strength, motor skills, and PA levels than term-born children. These findings suggest that preschool-aged children born <30 weeks may benefit from enhanced surveillance and PA promotion to improve life-long health outcomes., Impact: In our study, children born <30 weeks had reduced muscle strength and poorer motor skills, participated in less PA, and had more stationary and screen behavior than term-born children. These findings emphasize that awareness of multidomain motor deficits in children born <30 weeks' gestation is needed in clinical practice. Given the associations between higher PA and health benefits and the recognition that PA levels can track from early childhood into adulthood, our study highlights the need for assessment and promotion of PA in preschool-aged children born <30 weeks' gestation. Lay Summary. Preschool-aged children born <30 weeks' gestation have poorer strength, motor skills, and physical activity behaviors than their term-born peers. Clinicians and early childhood educators should recognize that the preschool period is a critical time for the assessment and promotion of PA in children born <30 weeks., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Physical Therapy Association. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Introduction: This double-blind, randomised controlled trial (RCT) aims to estimate the effect of a physiotherapist-led intervention with targeted strengthening compared with a physiotherapist-led intervention with standardised stretching, on hip-related quality of life (QOL) or perceived improvement at 6 months in people with femoroacetabular impingement (FAI) syndrome. We hypothesise that at 6 months, targeted strengthening physiotherapist-led treatment will be associated with greater improvements in hip-related QOL or greater patient-perceived global improvement when compared with standardised stretching physiotherapist-led treatment., Methods and Analysis: We will recruit 164 participants with FAI syndrome who will be randomised into one of the two intervention groups, both receiving one-on-one treatment with the physiotherapist over 6 months. The targeted strengthening physiotherapist-led treatment group will receive a personalised exercise therapy and education programme. The standardised stretching physiotherapist-led treatment group will receive standardised stretching and personalised education programme. Primary outcomes are change in hip-related QOL using International Hip Outcome Tool-33 and patient-perceived global improvement. Secondary outcomes include cost-effectiveness, muscle strength, range of motion, functional task performance, biomechanics, hip cartilage structure and physical activity levels. Statistical analyses will make comparisons between both treatment groups by intention to treat, with all randomised participants included in analyses, regardless of protocol adherence. Linear mixed models (with baseline value as a covariate and treatment condition as a fixed factor) will be used to evaluate the treatment effect and 95% CI at primary end-point (6 months)., Ethics and Dissemination: The study protocol was approved (La Trobe University Human Ethics Committee (HEC17-080)) and prospectively registered with the Australian New Zealand Clinical Trials Registry. The findings of this RCT will be disseminated through peer reviewed scientific journals and conferences. Patients were involved in study development and will receive a short summary following the completion of the RCT., Trial Registration Number: ACTRN12617001350314., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: The aims of this study were to (1) evaluate the relationships between stationary and dynamic associated reaction (AR) tests in people with acquired brain injury using surface electromyography (sEMG) muscle activity and three-dimensional motion analysis kinematic measures and (2) assess the test-retest reliability of sEMG and seated tests of ARs., Design: Forty-two adults with acquired brain injury underwent AR testing with seated contralateral maximal voluntary isometric contraction tests and walking (self-selected and fast speeds). Associated reaction measurements included biceps brachii sEMG, elbow goniometry, and three-dimensional motion analysis kinematics during walking. Pearson correlations evaluated the relationships between seated and dynamic walking AR tests and between muscle activity and kinematic measures. Chronic participants were reassessed 1 wk later for reliability., Results: A strong (r = 0.65) and moderate (r = 0.53) relationship existed for biceps brachii sEMG during seated and walking tests at self-selected and fast walk, respectively. A weak to moderate relationship existed between biceps brachii sEMG and kinematics during walking and between seated and walking measures of ARs (r = 0.23-0.53). All tests had strong to very strong test-retest reliability (intraclass correlation coefficients, >0.78)., Conclusion: Seated contralateral maximal voluntary isometric contraction tests correlate only weakly to moderately with AR walking kinematics and moderately to strongly with biceps brachii activation during walking. Moderate relationships exist between sEMG and kinematics, indicating that they may provide different information for ARs., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Measuring dynamic vertical ground reaction force allows for assessment of important clinical and physical capacity factors such as weight bearing asymmetry, force distribution, and rate of force development. However, current technologies for accurately assessing ground reaction force are typically expensive., Research Question: The aim of this study was to examine the validity and reliability of obtaining static and dynamic ground reaction force data from low-cost modified digital bathroom scales., Methods: Four modified bathroom scales, two units each of two different brands, were examined. Repeated mechanical loading trials were performed with known loads ranging from 0.01 to 65 kg, with acquired data compared against the known loading to calculate accuracy, hysteresis, and non-linearity. Dynamic trials consisting of 5 times sit-to-stand and weight-shifting were performed by 32 adults. Absolute and relative agreement intraclass correlation coefficient, and Pearson's and Spearman's correlations were performed to determine validity and reliability for the mechanical tests. Bland-Altmann plots were created for each comparison. Mean absolute error (MAE) and unbiased cross-correlation were performed on the dynamic data, comparing the calibrated data to the known values from a Bertec force platform., Results: Hysteresis and non-linearity were excellent (<0.2 % full-scale), and mechanical test results showed excellent reliability and validity. Cross-correlation results for the dynamic data were excellent, however MAE for the more rapid sit-to-stand task was higher than the slower weight-shifting test. This may have been due to the low default sampling rate for the lowest noise setting of the HX711 amplifier (10 Hz)., Significance: In summary, our results suggest that digital bathroom scales can be easily and inexpensively modified to obtain accurate vertical ground reaction force data, with sensitivity to detect changes of as little as 0.01 kg., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Hip-related pain (HRP) is described as a movement-related disorder. However, little attention is given to the way people with HRP move, especially in populations still participating in sport. Thus, limiting our understanding of movementbased impairments in HRP and their potential relationships with pain/symptoms., Research Question: (1) What are the differences in absolute and relative amounts of positive and negative lower-limb joint work during walking and the single-leg drop jump (SLDJ) in football players with and without HRP? (2) What are the relationships between lower-limb joint work and HRP burden?, Methods: 88 football players with HRP and 30 control football players were recruited. Positive and negative work done by the hip, knee, and ankle (and each joint's relative contribution to total work done) were calculated. The effect of sex on the relationship between HRP and work done, as well as the association between work done and International Hip Outcome Tool (iHOT33) scores, were assessed using linear and beta regressions models., Results: Walking: No joint work variables were significantly different between groups, nor were any relationships with iHOT33 scores evident. SLDJ: The knee's relative contribution to total lower-limb negative work done was 37.7 % and 42.4 % for women with and without HRP, respectively (P = 0.04). The iHOT33 was significantly associated with positive (P = 0.03 to <0.01) and negative (P = 0.02 to <0.01) work done by the hip as well as negative work done by the ankle (P = 0.03 to 0.01), independent of sex., Significance: Only one significant between-group comparison was revealed, involving the knee in female football players. In addition, football players with a greater selfreported burden of HRP tended to display lower hip joint work during the SLDJ. Rehabilitation programs could be targeted to address these impairments and normalize work done during high impact tasks in the management of HRP., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Deficits in knee flexor strength and rate of torque development (RTD) might be present in women with patellofemoral pain (PFP). In addition, maximal strength and RTD of the knee flexors and extensors might be related with subjective and objective function in women with PFP. However, both conjectures are still poorly understood., Research Question: Do women with PFP have deficits in the maximal strength and RTD of the knee flexors and extensors during isometric, concentric, and eccentric contractions? Is there a relationship between maximal strength and RTD of the knee flexors and extensors with subjective and objective function in women with PFP?, Methods: Fifty-six women with, and 46 women without, PFP participated. Maximal strength and RTD (to 30% and 60% maximal torque) during isometric, concentric, and eccentric contractions of the knee flexors and extensors were assessed using an isokinetic dynamometer. Objective assessment included single leg hop test (SLHT) and forward step-down test (FSDT). Subjective assessment involved the anterior knee pain scale., Results: Women with PFP had small to large deficits in maximal strength and RTD of the knee flexors and extensors during isometric, concentric and eccentric contractions (Effect sizes: -0.43 to -1.10; p ≤ 0.016). Small to moderate correlations of maximal concentric and eccentric knee flexor strength and RTD with SLHT and FSDT (r = 0.28 to 0.41; p ≤ 0.037) were identified. Subjective or objective function were not correlated with maximal isometric knee flexor strength and RTD, or any knee extensor measures (p > 0.05)., Significance: Maximal strength and RTD deficits of the knee flexors and extensors were identified in this female PFP cohort, but they were unrelated to subjective function. The relationship of concentric and eccentric knee flexor strength and RTD deficits with poor objective function should be considered in future exercise trials for women with PFP., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: Spasticity assessment is often used to guide treatment decision-making. Assessment tool limitations may influence the conflicting evidence surrounding the relationship between spasticity and walking. This study investigated whether testing speeds and joint angles during a Modified Tardieu assessment matched lower-limb angular velocity and range of motion during walking., Design: Observational study., Subjects: Thirty-five adults with a neurological condition and 34 assessors., Methods: The Modified Tardieu Scale was completed. Joint angles and peak testing speed during V3 (fast) trials were compared with these variables during walking in healthy people, at 0.400.59, 0.600.79 and 1.401.60 m/s. The proportion of trials in which the testing speed, start angle, and angle of muscle reaction matched the relevant joint angles and angular velocity during walking were analysed., Results: The Modified Tardieu Scale was completed faster than the angular velocities seen during walking in 88.7% (0.400.59 m/s), 78.9% (0.600.79 m/s) and 56.2% (1.401.60 m/s) of trials. When compared with the normative dataset, 4.2%, 9.5% and 13.7% of the trials met all criteria for each respective walking speed., Conclusion: When applied according to the standardized procedure and compared with joint angular velocity during walking, clinicians performed the Modified Tardieu Scale too quickly.

Background: Abnormal upper limb movements frequently affect people with acquired brain injury (ABI) during walking. Three-dimensional motion analysis (3DMA) can quantify upper limb abnormality kinematically, with composite scores condensing multiple joint axes data into a single score., Research Question: Are 3DMA-derived composite scores valid (known-groups and convergent validity), reliable and able to quantify speed-related changes in abnormal upper limb movement during walking?, Methods: This observational study compared 42 adults with ABI and abnormal upper limb movements during walking with 36 healthy controls (HC) at a matched walking speed intention. Participants underwent 3DMA assessment of self-selected and fast walking speeds. Composite scores quantified the affected upper limb's kinematic abnormality. The Arm Posture Score arithmetic mean version (APSam) and 1.96 standard deviation reference-range scaled versions; the Kinematic Deviation Score mean (KDSm) and worst score (KDSw) were evaluated for association with each other and subjective abnormality rating (Pearson's 'r' correlation), test-retest reliability (intra-class correlation coefficient (ICC)), and ability to quantify speed-related changes in abnormal upper limb movement (Cohen's d effect size (ES), % change scores)., Results: Very strong correlations existed between composite scores. The KDSm under-classified upper limb abnormality, whereas the KDSw captured the majority of ABI participants. All scores had moderate-strong correlations with subjective rating of abnormal upper limb movements (r = 0.54 - 0.79) and very strong test-retest reliability (ICCs > 0.81). The APSam demonstrated a 16% (ES = 0.76) walking speed-related increase in upper limb abnormality, whilst decreases were demonstrated in the KDSm 26% (ES 0.90) and KDSw 35% (ES 0.96)., Significance: The APSam, KDSw, and number of abnormal joint axes comprehensively assess the whole upper limb abnormal movements, accurately classifies abnormality, and quantifies severity. This study illustrated notable presence of abnormal upper limb movements at self-selected walking speed and small increase at fast speeds. However, when scaled to HC variability, the fast walk kinematics became less abnormal due to increased HC movement variability., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: To evaluate the effects of injury prevention programmes on injury incidence in any women's football code; explore relationships between training components and injury risk; and report injury incidence for women's football., Design: Systematic review and meta-analysis., Data Sources: Nine databases searched in August 2019., Eligibility Criteria: Randomised controlled trials evaluating any injury prevention programme (eg, exercise, education, braces) were included. Study inclusion criteria were: ≥20 female football players in each study arm (any age, football code or participation level) and injury incidence reporting., Results: Twelve studies, all in soccer, met inclusion criteria, with nine involving adolescent teams (aged <18 years). All studies (except one) had a high risk of bias. Eleven studies examined exercise-based programmes, with most (9/11) including multiple (≥2) training components (eg, strength, plyometric, balance exercises). Multicomponent exercise programmes reduced overall (any reported) injuries (incidence rate ratio (IRR) 0.73, 95% CI 0.59 to 0.91) and ACL injuries (IRR 0.55, 95% CI 0.32 to 0.92). For exercise-based strategies (single-component and multicomponent), hamstring injuries were also reduced (IRR 0.40, 95% CI 0.17 to 0.95). While exercise-based strategies resulted in less knee, ankle and hip/groin injuries, and the use of multiple training components was associated with greater reductions in overall and knee injuries, further studies would be required to increase the precision of these results. The incidence of overall injuries in women's football was 3.4 per 1000 exposure hours; with ankle injuries most common., Conclusion: In women's football, there is low-level evidence that multicomponent, exercise-based programmes reduce overall and ACL injuries by 27% and 45%, respectively., Prospero Registration Number: CRD42018093527., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)