Mechanical energy flow analysis in athletes with and without anterior cruciate ligament reconstruction during single-leg drop landing.

Techniques that reduce mechanical energy have been linked to lower chances of experiencing an Anterior Cruciate Ligament (ACL) injury. Although there is evidence that movement patterns are altered in athletes who have undergone Anterior Cruciate Ligament Reconstruction (ACLR), energy transfer mechanisms have not been examined. This study aimed to compare energy flow mechanisms during single-leg drop landing between athletes with and without history of ACLR. A total of 20 female athletes were included in this study. Ten participants underwent ACLR 12 months ago (mean age, 21.57 ± 0.41 years) and 10 were healthy controls (mean age, 20.89 ± 0.21 years). Participants executed the single-leg drop landing (SLL) maneuver by descending from a 30 cm wooden box and landing on the tested leg on an embedded force plate. Information collected during the SLL trials was refined using rigid-body analysis and inverse dynamics within Nexus software, ultimately allowing construction of skeletal models of the athletes. Ankle and knee mechanical energy expenditure (MEE) was higher in the control participants during landing. However, the result for the hip MEE demonstrated that MEE of the control group was significantly lower compared with the ACLR group, but MEE of the control subjects was higher as compared to ACLR group (p ˂ 0.05). Results suggest the avoidant use of the quadriceps muscle post ACLR leads to knee-avoidant mechanics and loss of knee joint power generation during a SLL task.

Association between physical activity and body posture: a systematic review and meta-analysis.

OBJECTIVE: To estimate the possible associations between posture and physical activity (PA). DESIGN: A systematic review and meta-analysis. DATA SOURCES: The search was conducted in seven databases (PubMed, Web of Science, SportDiscus, EMBASE, Scopus, Cochrane Library, and CINAHL) for studies published from inception to January 2023. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies were required to meet following criteria: (1) study design: cross-sectional, case control and cohort studies. (2) Participants: people of all ages without any diagnosed diseases. (3) Exposure and outcome: studies that examined the possible effect or correlations between PA, physical inactivity, physical exertion and human body posture. RESULTS: Sixteen cross-sectional studies, two cohort studies and one case control study involving a total of 16772 participants aged from 6 to 79 years were included. Correlational studies showed that there was a significant relationship between PA and posture (C = 0.100, CI 95% = 0.012-0.186). However, regression studies demonstrated that there was not a significant association between PA and posture (C = 1.00, CI 95% = 0.998-1.002). Three studies investigated the association between PA and the lumbar lordosis and showed that there was not a significant association between the lordosis and PA (CI 95%: -0.253-0.048, P = 0.180). In addition, four studies showed that there were not any associations between scoliosis and PA (CI 95%: 0.819, 1.123, P = 0.607). The evidence of heterogeneity and publication bias was found among all analyzed data (P < 0.05). Also, meta regression was used for age and BMI and the results were not significant. CONCLUSION: Although a weak correlation was shown to exist between PA and human posture, the odds ratio indicated that there was not a significant association between PA and human posture. The lack of a significant relationship may indicate that multiple biopsychosocial factors may be involved in human posture. In summary, our study highlights the need for caution when interpreting the results of meta-analyses, particularly when there is significant heterogeneity and publication bias in the included studies.

The association between size and symmetry of the lumbar multifidus muscle, and injuries in adolescent rugby union players.

OBJECTIVES: This study aimed to investigate the association between size and symmetry of the lumbar multifidus muscle, and season injuries in adolescent rugby union players. DESIGN: Prospective longitudinal cohort study. SETTING: Pre-season assessment of the size (cross-sectional area) of the lumbar multifidus (L2-5) muscles using ultrasound imaging. PARTICIPANTS: Seventy-one adolescent rugby union players (aged 15-18 years). MAIN OUTCOME MEASURES: "Time-loss" injuries were recorded during the season and divided into four injury regions (head and neck, upper limb, trunk and lower limb). RESULTS: Thirty-nine injuries were recorded during the season. Players who sustained an upper limb injury during the season had smaller lumbar multifidus muscles at the L5 vertebral level (effect size = 0.7, p = 0.03) and asymmetry in muscle size at the L2 (p = 0.05) and L5 (p = 0.04) in the pre-season. There was no association between size of the lumbar multifidus muscle and other injuries (p > 0.05). CONCLUSION: Lumbar multifidus muscle size and symmetry may impact lumbopelvic control which may increase the risk of sustaining an upper limb injury during rugby union. Future research should aim to identify whether lumbar multifidus muscle size is a modifiable risk factor for rugby union injuries to guide future intervention programs.

Evaluation of the vestibular/ocular motor screening assessment in active combat sport athletes: an exploratory study.

OBJECTIVE: The first aim of this study was to compare the results of the vestibular/ocular motor screening (VOMS) in combat sport athletes with a healthy control population. Second, to explore differences between athletes with and without a concussion history. Third, to examine the relationship between VOMS and the Post-Concussion Symptom Scale (PCSS) in combat sport athletes. PARTICIPANTS: Forty active male combat sport athletes and 40 healthy male control participants were recruited from 4 clubs and a University in Australia. METHODS: Participants completed the VOMS in a primary care physiotherapy clinic. Participants completed an injury questionnaire and the PCSS. RESULTS: An "abnormal" score in at least one subtest or near point convergence (NPC) was recorded in 45% of the combat group compared with 22.5% of the control group. All VOMS scores and NPC distance were greater in the combat group compared with control group (p < 0.05). The VOMS scores were found to be moderately positively correlated with the PCSS. There was no difference in VOMS between athletes with and without a history of concussion (p > 0.05). CONCLUSION: VOMS scores differed between combat sport athletes and control participants. The PCSS may aid clinicians in identifying athletes who have underlying vestibular/oculomotor impairment.

Nordic strength and history of hamstring injury in Australian Football League players.

OBJECTIVES: Compare hamstring strength between Australian Football League (AFL) players with and without a prior hamstring injury and determine the effect of the number of previous hamstring injuries, time since the last injury, and injury severity, on hamstring strength. DESIGN: Cross-sectional, retrospective. SETTING: AFL clubs. PARTICIPANTS: 124 AFL players. MAIN OUTCOME MEASURES: Bilateral hamstring strength was assessed on a Nordbord (Vald Performance) during the Nordic Hamstring Exercise. Self-reported questionnaires were used to record previous hamstring injuries. Players were categorized into No Injury or Hamstring Injury groups. Previously injured players were subgrouped based on number of prior hamstring injuries (single or multiple), time since the last hamstring injury (≤1 or > 1-year ago), and hamstring injury severity (≤3 or > 3 matches missed). RESULTS: 19 hamstring injuries were reported. Hamstring strength was not different between players with and without a history of hamstring injury when assessed in absolute (N) or relative (i.e., N.kg-1) terms. No differences in strength were detected between hamstring injury subgroups when assessed in absolute or relative terms. CONCLUSIONS: AFL players that experienced a previous hamstring injury did not exhibit deficits in hamstring strength relative to their uninjured limb or players without a previous hamstring injury.

Cervical spine characteristics differ in competitive combat athletes compared with active control participants.

BACKGROUND: Injury to the head and neck are common in combat sport athletes. Impairments of the cervical spine have been found in some athletes who participate in sports with high forces and collisions. There is a lack of research on the effects of combat sports on the cervical spine. OBJECTIVE: The primary study aim was to investigate differences in cervical spine characteristics between combat athletes and a similarly aged active control group. The secondary aim was to investigate the relationship between symptom-based outcome measures and characteristics of the cervical spine. DESIGN: Cross-sectional. METHOD: 40 male adult combat sport athletes and 40 male adult control participants were recruited from 4 combat sport clubs and a university campus, Australia. Cervical spine assessments were conducted at a private physiotherapy clinic. The Neck Disability Index and the Post-Concussion Symptom Scale were used as symptom-based outcome measures. RESULTS: Combat sport athletes had a reduced range of cervical motion, but greater isometric strength and endurance compared with a control group (p < 0.05). The Neck Disability Index and Post-Concussion Symptom Scale were negatively correlated with cervical spine range of motion and isometric strength, meaning that higher scores correlated with a reduction in function. CONCLUSIONS: Differences were observed in characteristics of the cervical spine in combat sport athletes compared with a control group. Higher symptom-based outcome scores correlated with reduced range of motion and strength of cervical spine muscles. Further investigation to establish clinical cut-off scores for functional impairment may be warranted.

Vestibular and oculomotor function in male combat sport athletes.

OBJECTIVES: To investigate for differences in vestibulo-ocular function between active male combat sport athletes and a healthy control group. In addition, to explore the relationship between symptom-based outcome measures with vestibulo-ocular function. DESIGN: Cross-sectional. METHODS: 40 male adult combat sport athletes and 40 active male control participants were recruited from 4 martial arts schools and a University campus in Queensland, Australia. All participants completed a standardised protocol which was used to assess vestibulo-ocular function. The protocol included 3 components: 1) oculomotor function, 2) benign paroxysmal positional vertigo screening, and 3) vestibulo-ocular reflex function. The Post-Concussion Symptom Scale, Vestibular/Ocular Motor Screening tool and Dizziness Handicap Inventory were used as symptom-based outcome measures. RESULTS: More combat sport athletes had oculomotor abnormalities than control group participants. There were no between group differences in benign paroxysmal positional vertigo, vestibulo-ocular reflex function and the video-head impulse test gain (ms). Combat sport athletes had higher symptom-based outcome scores. The Vestibular/Ocular Motor Screening tool and Dizziness Handicap Inventory were found to have moderate positive relationships with the total number of abnormalities detected in the combat sport group. CONCLUSIONS: Vestibulo-ocular function is imperative for combat sport athletes to perform evasive manoeuvres and land their own strikes. The present study findings may aid clinicians in the identification of combat sport athletes with underlying vestibulo-ocular dysfunction, prompting further investigation.

Trunk muscle size and function in volleyball players with and without injuries to the head, neck and upper limb.

OBJECTIVE: To investigate trunk muscle size and function in elite and community volleyball players with and without a history of head, neck or upper limb injury. DESIGN: Cross-sectional observational study. SETTING: Volleyball training camp or training sessions. PARTICIPANTS: 86 volleyball players (elite = 29; community = 57). MAIN OUTCOME MEASURES: Information regarding history of head, neck or upper limb injuries was collected by self-report questionnaires. Trunk muscle size (multifidus, transversus abdominis, internal oblique and quadratus lumborum) and voluntary contraction (multifidus, transversus abdominis, internal oblique) were assessed using ultrasound imaging. RESULTS: For trunk muscle size, no significant differences were found between elite and community volleyball players with and without a history of injury (all p > 0.05). A significant difference was found for voluntary contraction of the multifidus and transversus abdominis muscles for elite and community volleyball players with and without a history of injury (all p < 0.05). CONCLUSION: A difference in trunk muscle contraction but no change in trunk muscle size in players with a history of head, neck or upper limb injuries may represent an altered muscle recruitment pattern rather than a deficiency in trunk muscle strength. Prospective studies are required to determine if these adaptations are compensatory (and protective) or predispose players to further injuries.

Sensorimotor system changes in adolescent rugby players post-concussion: A prospective investigation from the subacute period through to return-to-sport.

BACKGROUND: The pathophysiology of concussion is complex. Altered sensorimotor function post-concussion may contribute to the wide range of symptoms and impairments reported. There is currently limited evidence documenting changes in sensorimotor function during the recovery period. The aim of this study was to investigate the effect of concussion on the sensorimotor system in adolescents post-concussion using a multifaceted approach. STUDY DESIGN: Prospective nested case-control study. METHODS: A total of 285 male adolescent rugby players underwent assessment of sensorimotor function during preseason. Players who sustained a concussion during the season and control players, matched for age and playing position, were assessed in the subacute period (3-5 days) and after return-to-sport (3 weeks). Tests of sensorimotor function included balance, cervical spine and vestibulo-ocular function, and measurement of the size and contraction of lumbopelvic muscles (ultrasound imaging). RESULTS: Twenty-three players (8%) sustained a concussion. Of these, 20 players were assessed during the subacute period and 17 players following return-to-sport. The prevalence of vestibulo-ocular dysfunction increased from 38.9% to 72.2% during the subacute period and dysfunction was present in 83.3% of players after return-to-sport (p = 0.01). Changes in lumbar multifidus muscle size (p = 0.002) and thickness (p = 0.05) at the L5 vertebral level were observed. No statistically significant changes in balance, cervical spine proprioception, or contraction of lumbopelvic muscles were found (p > 0.05). CONCLUSION: Changes in sensorimotor function were observed in the subacute period post-concussion, with some persisting after return-to-sport. Using symptom-based criteria for return-to-sport may not adequately reflect the sequelae of concussion on the sensorimotor system.

The prevalence and burden of recurrent headache in Australian adolescents: findings from the longitudinal study of Australian children.

BACKGROUND: Headache disorders are highly prevalent worldwide, but not well investigated in adolescents. Few studies have included representative nationwide samples. This study aimed to present the prevalence and burden of recurrent headache in Australian adolescents. METHODS: The prevalence of recurrent headache, headache characteristics (severity and frequency) and burden on health-related quality of life in Australian children aged 10-17 years were presented, using nationally representative data from the Longitudinal Study of Australian children (LSAC). The LSAC, commencing in 2004, collects data every 2 years from a sample of Australian children of two different age cohorts: B 'baby' cohort, aged 0-1 years and K 'kindergarten' cohort, aged 4-5 years at the commencement of the study. Face-to-face interviews and self-complete questionnaires have been conducted with the study child and parents of the study child (carer-reported data) at each data collection wave, with seven waves of data available at the time of the current study. Wave 7 of the LSAC was conducted in 2016, with B cohort children aged 12-13 years and K cohort children aged 16-17 years. For the current study, data were accessed for four out of seven waves of available data (Wave 4-7) and presented cross-sectionally for the two cohorts of Australian children, for the included age groups (10-11 years, 12-13 years, 14-15 years and 16-17 years). All available carer-reported questionnaire data pertaining to headache prevalence, severity and frequency, general health and health-related quality of life, for the two cohorts, were included in the study, and presented for male and female adolescents. Carer-reported general health status of the study child and health-related quality of life scores, using the parent proxy-report of the Paediatric Quality of Life Inventory™ 4.0, were compared for male and female adolescents with recurrent headache and compared with a healthy group. Finally, health-related quality of life scores were compared based on headache frequency and severity. RESULTS: The LSAC study initially recruited 10,090 Australian children (B cohort n = 5107, K cohort n = 4983), and 64.1% of the initial sample responded at wave 7. Attrition rates across the included waves ranged from 26.3% to 33.8% (wave 6 and 7) for the B cohort, and 16.3% to 38.0% (wave 4-7) for the K cohort. Recurrent headache was more common in females, increasing from 6.6% in 10-11 years old females to 13.2% in 16-17 years old females. The prevalence of headache in males ranged from 4.3% to 6.4% across the age groups. Health-related quality of life scores were lower for all functional domains in adolescents with recurrent headache, for both sexes. Headache frequency, but not severity, was significantly associated with lower health-related quality of life scores, in both males and females. CONCLUSIONS: Recurrent headache was common among Australian adolescents and increased in prevalence for females, across the age groups. Frequent recurrent headache is burdensome for both male and female adolescents. This study provides information regarding the prevalence and burden of recurrent headache in the adolescent population based on findings from the Longitudinal Study of Australian Children.

Lower limb joint position sense and prospective hamstring injury.

BACKGROUND: The hamstrings remain the most injured muscle group within the Australian Football League (AFL). OBJECTIVE: To investigate preseason measures of hip and knee joint position sense (JPS) and prospective hamstring injury in AFL players. DESIGN: Prospective cohort study. METHODS: A total of 116 AFL players were recruited for this study. JPS was assessed with 3-D sensors using mono-articular hip (45° flexion and 0°) and knee (90° and 45° flexion) joint reproduction tests conducted in the preseason. Hamstring injury data were collected prospectively in the following AFL season. Wilcoxon-signed rank tests were used to assess between the subsequently injured and uninjured limbs. Mann-Whitney U tests were used to assess between group differences and odds ratio (OR) were used to predict players at risk of hamstring injury. RESULTS: Eight players with JPS data sustained a season hamstring injury and 108 players did not. JPS was not significantly different between the subsequently injured and uninjured limbs (all P values > 0.05). No significant differences for any JPS measure were found between the subsequently injured and uninjured players (all p's > 0.05). ORs did not achieve significance for AE (2.7, p = 0.21) or for RMSE (OR = 1.9, p = 0.44). CONCLUSION: Lower limb JPS measures were not predictive of hamstring injury in AFL players.

A prospective study of risk factors for hamstring injury in Australian football league players.

This study aimed to explore the association between hamstring strength, age and lower limb soft tissue injury history and subsequent hamstring injury among Australian Football League (AFL) players. This prospective cohort study recruited 125 players from three professional AFL teams. Eccentric knee flexor strength was assessed while performing the Nordic hamstring exercise in pre-season, and injury data were collected retrospectively (hamstring, groin, calf, quadriceps and knee), and prospectively (hamstring injuries) for one AFL playing season. Fourteen players (11%) sustained a hamstring injury in the subsequent playing season. Nordic strength was not significantly associated with future hamstring injury (Odds Ratio (OR) 1.9, p = 0.36), whereas player age greater than 25 years (OR = 2.9, p < 0.05), report of a hamstring injury within the previous year (OR = 3.7, p = 0.01), or greater than 1-year (OR = 3.6, p = 0.01), a previous groin (OR = 8.6, p < 0.01) or calf injury (OR = 4.6, p = 0.01) were factors significantly associated with subsequent hamstring injury. Based on these findings, increasing age and previous hamstring, groin and calf injury are all associated with an elevated risk of subsequent hamstring injury in AFL players.

The association of concussion history and symptom presentation in combat sport athletes.

OBJECTIVE: The purpose of this study was to describe the concussion-related symptoms reported among combat sport athletes with and without a history of concussion, and a history of neck injury. DESIGN: Cross-sectional survey. SETTING: Data were collected using an online survey instrument. PARTICIPANTS: Three hundred and nine adult combat sport athletes. MAIN OUTCOME MEASURES: Self-reported 12-month concussion history and neck injury history and a 22-item symptom checklist. RESULTS: A history of concussion was reported by 19.1% of athletes, a history of neck injury was reported by 23.0%, and 13.6% reported both injuries. Neck pain was the most frequently reported symptom. Athletes with a history of injury had significantly greater proportions of 'high' total symptoms and symptom severity scores compared with athletes with no history of injury. Athletes with a history of concussion had 2.35 times higher odds of reporting 'high' total symptoms and symptoms severity scores. CONCLUSION: Athletes with a history of concussion or neck injury have greater odds of presenting with higher symptom scores. The presence of high total symptom scores and high symptom severity scores may indicate a need for further investigation into domains commonly associated with concussion.

The effects of exposure to microgravity and reconditioning of the lumbar multifidus and anterolateral abdominal muscles: implications for people with LBP.

BACKGROUND CONTEXT: One of the primary changes in the neuromuscular system in response to microgravity is skeletal muscle atrophy, which occurs especially in muscles that maintain posture while being upright on Earth. Reduced size of paraspinal and abdominal muscles has been documented after spaceflight. Exercises are undertaken on the International Space Station (ISS) during and following space flight to remediate these effects. Understanding the adaptations which occur in trunk muscles in response to microgravity could inform the development of specific countermeasures, which may have applications for people with conditions on Earth such as low back pain (LBP). PURPOSE: The aim of this study was to examine the changes in muscle size and function of the lumbar multifidus (MF) and anterolateral abdominal muscles (1) in response to exposure to 6 months of microgravity on the ISS and (2) in response to a 15-day reconditioning program on Earth. DESIGN: Prospective longitudinal series. PATIENT SAMPLE: Data were collected from five astronauts who undertook seven long-duration missions on the ISS. OUTCOME MEASURES: For the MF muscle, measures included cross-sectional area (CSA) and linear measures to assess voluntary isometric contractions at vertebral levels L2 to L5. For the abdominal muscles, the thickness of the transversus abdominis (TrA), obliquus internus abdominis (IO) and obliquus externus abdominis (EO) muscles at rest and on contraction were measured. METHODS: Ultrasound imaging of trunk muscles was conducted at four timepoints (preflight, postflight, mid-reconditioning, and post reconditioning). Data were analyzed using multilevel linear models to estimate the change in muscle parameters of interest across three time periods. RESULTS: Beta-coefficients (estimates of the expected change in the measure across the specified time period, adjusted for the baseline measurement) indicated that the CSA of the MF muscles decreased significantly at all lumbar vertebral levels (except L2) in response to exposure to microgravity (L3=12.6%; L4=6.1%, L5=10.3%; p<.001), and CSAs at L3-L5 vertebral levels increased in the reconditioning period (p<.001). The thickness of the TrA decreased by 34.1% (p<.017), IO decreased by 15.4% (p=.04), and the combination of anterolateral abdominal muscles decreased by 16.2% (p<.001) between pre- and postflight assessment and increased (TrA<0.008; combined p=.035) during the postreconditioning period. Results showed decreased contraction of the MF muscles at the L2 (from 12.8% to 3.4%; p=.007) and L3 (from 12.2% to 5%; p=.032) vertebral levels following exposure to microgravity which increased (L2, p=.046) after the postreconditioning period. Comparison with preflight measures indicated that there were no residual changes in muscle size and function after the postreconditioning period, apart from CSA of MF at L2, which remained 15.3% larger than preflight values (p<.001). CONCLUSIONS: In-flight exercise countermeasures mitigated, but did not completely prevent, changes in the size and function of the lumbar MF and anterolateral abdominal muscles. Many of the observed changes in size and control of the MF and abdominal muscles that occurred in response to prolonged exposure to microgravity paralleled those seen in people with LBP or exposed to prolonged bed rest on Earth. Daily individualized postflight reconditioning, which included both motor control training and weight-bearing exercises with an emphasis on retraining strength and endurance to re-establish normal postural alignment with respect to gravity, restored the decreased size and control of the MF (at the L3-L5 vertebral levels) and anterolateral abdominal muscles. Drawing parallels between changes which occur to the neuromuscular system in microgravity and which exercises best recover muscle size and function could help health professionals tailor improved interventions for terrestrial populations. Results suggested that the principles underpinning the exercises developed for astronauts following prolonged exposure to microgravity (emphasizing strength and endurance training to re-establish normal postural alignment and distribution of load with respect to gravity) can also be applied for people with chronic LBP, as the MF and anterolateral abdominal muscles were affected in similar ways in both populations. The results may also inform the development of new astronaut countermeasures targeting the MF and abdominal muscles.

Evaluation of patellar tendinopathy using the single leg decline squat test: Is pain location important?

STUDY DESIGN: A cross-sectional study of non-elite volleyball players aged 13-17years. OBJECTIVES: To evaluate the presence and location of pain during the single leg decline squat (SLDS) and compare patellar tendon thickness, structure, neovascularisation and symptom severity between SLDS-derived groups. METHODS: 32 male and 25 female participants attending a 5-day volleyball training camp underwent clinical evaluation by SLDS, describing the location of pain during this test using a pain map. The patellar tendon was examined using ultrasound imaging, performed by an assessor blinded to other assessments. Differences between participants experiencing local patellar tendon pain (PTP), other knee pain (OKP) or no-pain during the SLDS were evaluated. RESULTS: Fifteen (26.3%) participants experienced pain during the SLDS. Local PTP was recorded for 12.3% and OKP for 10.5% of right legs. The PTP group was distinguished from the other groups by larger thickness and cross-sectional area of the mid-patellar tendon (p < 0.001), more frequent neovascularisation (p = 0.005) and greater pain and disability (p < 0.036). No differences between OKP and no-pain groups was observed. CONCLUSION: Adolescent non-elite volleyball players reported symptoms indicative of patellar tendinopathy. In this cohort, the SLDS test combined with a pain map was associated with imaging and questionnaire-based outcomes. LEVEL OF EVIDENCE: Diagnosis, Level 2; Cross-sectional study.

Hip muscle atrophy in patients with acetabular labral joint pathology.

Intra-articular hip joint pathology is a source of hip and groin pain in active individuals and is thought to be a precursor to hip osteoarthritis. Limited evidence exists to guide appropriate physiotherapy management for these patients. Identification of which hip muscles are affected may help clinicians to develop effective exercise programs. A cross-sectional observational study in a hospital setting was conducted to investigate the size of individual hip abductor, hip extensor, and hip external rotator muscles in patients with acetabular labral joint pathology compared with age and sex matched healthy subjects. Twelve participants (eight females, four males), aged 20-53 years, with a medical diagnosis of unilateral acetabular labral tear and 12 healthy participants were recruited. Magnetic resonance imaging was used to assess cross-sectional areas of the gluteus minimus, gluteus medius, upper gluteus maximus, lower gluteus maximus, piriformis, and quadratus femoris muscles bilaterally. Gluteus medius muscle cross-sectional area was significantly different between groups (P < 0.01, effect size = 0.92) with muscle size found to be smaller in the pathology group. No differences were found for the other hip muscles (P > 0.05). These findings suggest that hip muscles are not all affected equally by the presence of intra-articular hip joint pathology. Atrophy of specific hip muscles, which are important in hip joint and pelvic stability, may alter hip joint function during gait and functional tasks. Clinicians treating patients with intra-articular hip joint pathology may need to prescribe exercises targeting the specific muscles with demonstrated dysfunction. Clin. Anat. 33:538-544, 2020. © 2019 Wiley Periodicals, Inc.

Predicting a beneficial response to motor control training in patients with low back pain: a longitudinal cohort study.

PURPOSE: Exercise therapy such as motor control training (MCT) has been shown to reduce pain and disability in people with low back pain (LBP). It is unknown which patients are most likely to benefit. This longitudinal cohort study aimed to: (1) retrospectively examine records from a large cohort of patients who received MCT treatment, (2) identify potentially important predictors of response to MCT and (3) test the predictors on an independent (split) sample derived from the original cohort of patients, using one group to identify the predictors and the other to test them. METHODS: The response of 775 patients with LBP to MCT was classified as 'improved' or 'not improved' based on self-reported change in pain levels and symptoms. Measures were examined for associations with improvement and entered into a logistic regression model to classify patients as low, medium or high benefits of improvement with MCT. The model was tested on an independent sample. RESULTS: A positive response was seen in patients with: no evidence of scoliosis [OR = 4.0, 95% CI (1.7, 9.6)], LBP without associated groin pain [OR = 2.2, 95% CI (1.0, 5.0)], LBP which was chronic recurrent in nature [OR = 3.1, 95% CI (1.8, 5.3)] and poor results on muscle testing of the multifidus muscle [OR = 2.0, 95% CI (1.1, 3.7)]. Testing on an independent sample confirmed that patients could be classified into benefit groups. CONCLUSIONS: This study provides a first step towards assisting clinicians to select patients most likely to respond to MCT. These slides can be retrieved under Electronic Supplementary Material.

Convergence and Divergence of Exercise-Based Approaches That Incorporate Motor Control for the Management of Low Back Pain.

SYNOPSIS: Many approaches for low back pain (LBP) management focus on modifying motor control, which refers to motor, sensory, and central processes for control of posture and movement. A common assumption across approaches is that the way an individual loads the spine by typical postures, movements, and muscle activation strategies contributes to LBP symptom onset, persistence, and recovery. However, there are also divergent features from one approach to another. This commentary presents key principles of 4 clinical physical therapy approaches, including how each incorporates motor control in LBP management, the convergence and divergence of these approaches, and how they interface with medical LBP management. The approaches considered are movement system impairment syndromes of the lumbar spine, Mechanical Diagnosis and Therapy, motor control training, and the integrated systems model. These were selected to represent the diversity of applications, including approaches using motor control as a central or an adjunct feature, and approaches that are evidence based or evidence informed. This identification of areas of convergence and divergence of approaches is designed to clarify the key aspects of each approach and thereby serve as a guide for the clinician and to provide a platform for considering a hybrid approach tailored to the individual patient. J Orthop Sports Phys Ther 2019;49(6):437-452. Epub 15 May 2019. doi:10.2519/jospt.2019.8451.

Vestibulo-ocular dysfunction in adolescent rugby union players with and without a history of concussion.

OBJECTIVES: Sport-related concussions are common in adolescent contact sports. Vestibulo-ocular dysfunction has been reported in athletes post-concussion. There is a lack of research on vestibulo-ocular function in sporting adolescents, and the influence of previous concussions on the vestibular system in this population. The aim of this study was to investigate vestibulo-ocular function in a cohort of adolescent rugby players with and without a history of concussion during pre-season assessment. DESIGN: Cross-sectional cohort. METHODS: 213 male adolescent (13-18 years old) rugby players were recruited from six schools in Queensland, Australia. Vestibulo-ocular assessments were conducted during the preseason and included clinical assessment of oculomotor function and the vestibulo-ocular reflex (VOR) using the clinical and video-Head Impulse Test (HIT). Players were allocated into two groups: no history of concussion in the last 12 months (n = 165); and concussion in the last 12 months (n = 48). RESULTS: There were no between group differences in vestibulo-ocular function for players with and without a history of concussion (p = 0.65). However, vestibulo-ocular dysfunction was reported in 69 (32.7%) of the players tested, who had either abnormal oculomotor control or VOR function. CONCLUSIONS: The high prevalence of vestibulo-ocular dysfunction in adolescent rugby players suggests that positive clinical findings post-concussion need to be interpreted carefully in the absence of baseline or pre-concussion assessments.

Intrinsic foot muscle size can be measured reliably in weight bearing using ultrasound imaging.

BACKGROUND: The intrinsic foot muscles (IFMs) are important contributors to optimal foot function. While assessment of IFM morphology using ultrasound imaging in non-weight bearing has been established, this does not evaluate the foot in its primary functional position of weight bearing. RESEARCH QUESTION: Is ultrasound imaging a reliable and clinically feasible method of measuring IFM morphology in weight bearing, do these measures differ to those from non-weight bearing and are they associated with participant characteristics? METHODS: Ultrasound images were obtained by a single rater from twenty-four healthy participants on two occasions, one week apart. Images were taken in weight bearing (bilateral stance) and non-weight bearing (seated). Cross-sectional area and thickness of the abductor hallucis muscle, and dorsoplantar thickness of the muscles of the first interstitium were measured from acquired images. A second rater also acquired images at the first session. Participant characteristics included age, height, weight, sex, foot posture and foot mobility. RESULTS: Measurements of IFM morphology demonstrated high reliability within and between test sessions, as well as between raters (ICCs > 0.8). Our findings suggest that changes of 10-18% could be considered to exceed measurement error. Larger IFM size was related to larger body size (taller, heavier), foot posture (longer foot, higher arch, wider midfoot) and male sex. SIGNIFICANCE: This study is the first to describe a reliable and clinically feasible method of measuring IFM morphology in weight bearing. These measurements could be used in future studies to assess IFM morphology in patient populations and to evaluate the effect of intervention. Body size and foot posture explained between 20 and 41% of the variance in measurements and should be considered when comparing IFM morphology between individuals. The establishment of reliable measurements in weight bearing provides a crucial step towards the future evaluation of IFM function using ultrasound imaging.