Increased Duration and Intensity of Physical Activity Are Associated With Increased Pain in Individuals With Femoroacetabular Impingement Syndrome: An Ecological Momentary Assessment Study.

OBJECTIVE: To investigate the relation between accelerometer-measured physical activity and real-time pain in individuals with femoroacetabular impingement syndrome (FAIS). We tested the hypothesis that increased duration of high intensity activity would contribute to momentary increases in pain. DESIGN: Observational study. SETTING: Participants' natural, day-to-day environment. PARTICIPANTS: Population-based sample of 33 individuals with unilateral FAIS. Important eligibility criteria included no concomitant hip disorders or previous hip surgery. Key sociodemographic features include that all participants were required to have a smartphone. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Duration and intensity of physical activity as measured by a waist-worn accelerometer, and instantaneous pain reported in real-time smartphone-based ecological momentary assessment surveys. Physical activity variables included each person's average sedentary time, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) in the 90 minutes proceeding all pain surveys as well as fluctuation in sedentary, LPA, and MVPA above or below average prior to each individual survey. RESULTS: Linear mixed models revealed that the significant predictors of pain included fluctuation in sedentary time (B=-0.031, P<.001), average LPA (B=0.26, P=.035), and the interaction between fluctuation in LPA and fluctuation in MVPA (B=0.001, P<.001). Fluctuation in sedentary time above a person's average was associated with lower pain, while average LPA and fluctuations above average in both LPA and MVPA were associated with higher pain. CONCLUSIONS: These results suggest that individuals with FAIS can engage in health-enhancing MVPA but should focus on avoiding concurrent increase above average in both high intensity and LPA in the same 90-minute period. Future work is warranted testing the efficacy of such an approach on pain. Additionally, given that high levels of LPA may arise from a host of socioeconomic factors, additional research is needed to disentangle the effect of LPA on pain in FAIS.

Protocol and validity testing of femoroacetabular posterior translation with dynamic hip ultrasonography.

OBJECTIVE: To describe femoroacetabular posterior translation (FAPT) using dynamic hip ultrasonography (DHUS), and to determine the inter- and intra-rater reliability of hip ultrasound measurements of FAPT. MATERIALS AND METHODS: The study design was a feasibility study of 13 healthy young adults (26 hips) using test-retest analysis. The data was collected prospectively over a 2-week time period. Three DHUS measurements (posterior neutral (PN), flexion, adduction, and internal rotation (PFADIR), and stand and load (PStand) were measured by four independent raters (2 senior who divided the cohort, 1 intermediate, 1 junior) at two time points for bilateral hips of each participant. Reliability was assessed by calculating the intraclass correlation coefficient (ICC) along with 95% confidence intervals (CIs) for each rater and across all raters. RESULTS: A total of 468 US scans were completed. The mean age of the cohort was 25.7 years (SD 5.1 years) and 54% were female. The inter-rater reliability was excellent for PFADIR (ICC 0.85 95% CI 0.76-0.91), good for PN (ICC 0.69 95% CI 0.5-0.81), and good for PStand (ICC 0.72 95% CI 0.55-0.83). The intra-rater reliability for all raters was good for PFADIR (ICC 0.60 95% CI 0.44-0.73), fair for PN (ICC 0.42 95% CI 0.21-0.59), and fair for PStand (ICC 0.42 95% CI 0.22-0.59). CONCLUSION: This is the first study to present a protocol using dynamic ultrasonography to measure FAPT. DHUS measure for FAPT was shown to be reliable across raters with varying levels of ultrasound experience.

Gait, physical activity and tibiofemoral cartilage damage: a longitudinal machine learning analysis in the Multicenter Osteoarthritis Study.

OBJECTIVE: To (1) develop and evaluate a machine learning model incorporating gait and physical activity to predict medial tibiofemoral cartilage worsening over 2 years in individuals without advanced knee osteoarthritis and (2) identify influential predictors in the model and quantify their effect on cartilage worsening. DESIGN: An ensemble machine learning model was developed to predict worsened cartilage MRI Osteoarthritis Knee Score at follow-up from gait, physical activity, clinical and demographic data from the Multicenter Osteoarthritis Study. Model performance was evaluated in repeated cross-validations. The top 10 predictors of the outcome across 100 held-out test sets were identified by a variable importance measure. Their effect on the outcome was quantified by g-computation. RESULTS: Of 947 legs in the analysis, 14% experienced medial cartilage worsening at follow-up. The median (2.5-97.5th percentile) area under the receiver operating characteristic curve across the 100 held-out test sets was 0.73 (0.65-0.79). Baseline cartilage damage, higher Kellgren-Lawrence grade, greater pain during walking, higher lateral ground reaction force impulse, greater time spent lying and lower vertical ground reaction force unloading rate were associated with greater risk of cartilage worsening. Similar results were found for the subset of knees with baseline cartilage damage. CONCLUSIONS: A machine learning approach incorporating gait, physical activity and clinical/demographic features showed good performance for predicting cartilage worsening over 2 years. While identifying potential intervention targets from the model is challenging, lateral ground reaction force impulse, time spent lying and vertical ground reaction force unloading rate should be investigated further as potential early intervention targets to reduce medial tibiofemoral cartilage worsening.

Hip and Trunk Muscle Activity and Mechanics During Walking With and Without Unilateral Weight.

Pelvic drop is caused by decreased hip abductor muscle activity and is associated with lower-extremity injury. Hip abductor strengthening exercises are well established; however, no standard method exists to increase hip abductor activity during functional activities. The purpose of this research was to study the effects of walking with a unilateral weight. A total of 26 healthy adults walked on an instrumented treadmill with and without handheld weight (15%-20% body weight). Muscle activity, kinematic, and kinetic data were collected using surface electromyography, motion capture, and force plates, respectively. Average hip and trunk muscle activity, hip, pelvic, and trunk angles, and peak internal hip moments during stance were compared for each side (contralateral/ipsilateral to the weight) between conditions (unweighted/weighted) using a generalized linear model with generalized estimating equation correction. Interactions between condition and side were observed for muscle activity, frontal plane pelvic and trunk angles, and frontal plane hip moments (P ≤ .003). Compared with the unweighted condition, the weighted condition had higher hip abductor activity contralateral to the weight (P < .001), while no change was found ipsilateral to the weight (P ≥ .790). Similar changes were found for kinematic and kinetic variables. Walking with a unilateral weight may be a therapeutic option to increase functional hip abductor activity.

Patient-reported outcome measures for hip-related pain: a review of the available evidence and a consensus statement from the International Hip-related Pain Research Network, Zurich 2018.

Hip-related pain is a well-recognised complaint among active young and middle-aged active adults. People experiencing hip-related disorders commonly report pain and reduced functional capacity, including difficulties in executing activities of daily living. Patient-reported outcome measures (PROMs) are essential to accurately examine and compare the effects of different treatments on disability in those with hip pain. In November 2018, 38 researchers and clinicians working in the field of hip-related pain met in Zurich, Switzerland for the first International Hip-related Pain Research Network meeting. Prior to the meeting, evidence summaries were developed relating to four prioritised themes. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of PROMs to assess disability in young and middle-aged active adults with hip-related pain. Our process to gain consensus had five steps: (1) systematic review of systematic reviews; (2) preliminary discussion within the working group; (3) update of the more recent high-quality systematic review and examination of the psychometric properties of PROMs according to established guidelines; (4) formulation of the recommendations considering the limitations of the PROMs derived from the examination of their quality; and (5) voting and consensus. Out of 102 articles retrieved, 6 systematic reviews were selected and assessed for quality according to AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). Two showed moderate quality. We then updated the most recent review. The updated literature search resulted in 10 additional studies that were included in the qualitative synthesis. The recommendations based on evidence summary and PROMs limitations were presented at the consensus meeting. The group makes the following recommendations: (1) the Hip and Groin Outcome Score (HAGOS) and the International Hip Outcome Tool (iHOT) instruments (long and reduced versions) are the most appropriate PROMs to use in young and middle-aged active adults with hip-related pain; (2) more research is needed into the utility of the HAGOS and the iHOT instruments in a non-surgical treatment context; and (3) generic quality of life measures such as the EuroQoL-5 Dimension Questionnaire and the Short Form Health Survey-36 may add value for researchers and clinicians in this field. We conclude that as none of the instruments shows acceptable quality across various psychometric properties, more methods studies are needed to further evaluate the validity of these PROMS-the HAGOS and iHOT-as well as the other (currently not recommended) PROMS.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018.

There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

Standardised measurement of physical capacity in young and middle-aged active adults with hip-related pain: recommendations from the first International Hip-related Pain Research Network (IHiPRN) meeting, Zurich, 2018.

Hip-related pain can significantly impact quality of life, function, work capacity, physical activity and family life. Standardised measurement methods of physical capacity of relevance to young and middle-aged active adults with hip-related pain are currently not established. The aim of this consensus paper was to provide recommendations for clinical practice and research on standardised measurement methods of physical capacity in young and middle-aged active adults with hip-related pain. Four areas of importance were identified: (1) clinical measures (range of motion, muscle strength, functional impairments), (2) laboratory-based measures (biomechanics and muscle function (muscle activity, size and adiposity)), (3) physical activity, and (4) return to sport/performance. The literature was reviewed, and a summary circulated to the working group to inform discussion at the consensus meeting. The working group developed clinical and research recommendations from the literature review, which were further discussed and modified within the working group at the consensus meeting. These recommendations were then presented to all 38 International Hip-related Pain Research Network (IHiPRN) participants for further discussion, refinement and consensus voting. Therefore, the recommendations voted on were based on a combination of current evidence and expert opinion. The consensus meeting voted on 13 recommendations, six of which were clinically orientated, and seven more research specific. We recommended that clinicians working with young and middle-aged active adults with hip-related pain assess strength using objective methods of measurement, and clinically assess performance of functional tasks, including walking and running. Physical activity should be quantified using both self-reported and objective measures, and patient expectations of recovery should be quantified prior to treatment. It was recommended that return to physical activity (including sport and occupation) be quantified, and sport-specific activities should be assessed prior to return to sport. The IHiPRN participants were uncertain regarding recommendations for range of motion assessment. Research recommendations were that the measurement properties of range of motion, strength and functional performance tests be investigated, reported and improved in both clinical and research settings. Reporting of movement-related parameters (biomechanics and muscle function) should be standardised and the relationship among movement-related parameters, symptoms, function, quality of life, and intra-articular and imaging findings should be investigated. Quantification of return to physical activity (including sport and occupational demands) is required in future research, and the return to sport continuum should be used. Future research is required to determine the best criteria for rehabilitation progression and return to physical activity following hip-related pain management.

Physiotherapist-led treatment for young to middle-aged active adults with hip-related pain: consensus recommendations from the International Hip-related Pain Research Network, Zurich 2018.

The 1st International Hip-related Pain Research Network meeting discussed four prioritised themes concerning hip-related pain in young to middle-aged adults: (1) diagnosis and classification of hip-related pain; (2) patient-reported outcome measures for hip-related pain; (3) measurement of physical capacity for hip-related pain; (4) physiotherapist-led treatment for hip-related pain. Thirty-eight expert researchers and clinicians working in the field of hip-related pain attended the meeting. This manuscript relates to the theme of physiotherapist-led treatments for hip-related pain. A systematic review on the efficacy of physiotherapist-led interventions for hip-related pain (published separately) was conducted and found that strong evidence for physiotherapist-led treatments was lacking. Prior to the meeting, draft consensus recommendations for consideration in the meeting were also developed based on the systematic review. The draft consensus recommendations were presented to all of the meeting participants via email, at least 1 week prior to the meeting. At the meeting, these recommendations were discussed, revised and voted on. Six recommendations for clinical practice and five recommendations for research were included and all gained consensus. Recommendations for clinical practice were that (i) Exercise-based treatments are recommended for people with hip-related pain. (ii) Exercise-based treatment should be at least 3 months duration. (iii) Physiotherapist-led rehabilitation after hip surgery should be undertaken. (iv) Patient-reported outcome measures, measures of physical impairment and measures of psychosocial factors should be used to monitor response to treatment. (v) Physical activity (that may include sport) is recommended for people with hip-related pain. (vi) Clinicians should discuss patient expectations, use shared-decision making and provide education. Recommendations for research were (i) Reporting of exercise programmes: Exercise descriptors such as load magnitude, number of repetitions and sets, duration of whole programme, duration of contractile element of exercise, duration of one repetition, time under tension, rest between repetitions, range of motion through which the exercise is performed, and rest between exercise sessions should be reported. (ii) Research should investigate the optimal frequency, intensity, time, type, volume and progression of exercise therapy. (iii) Research should examine the effect of patient education in people with hip-related pain. (iv) Research should investigate the effect of other treatments used in people with hip-related pain (for example: manual therapy, medications, injections). (v) Research should examine the impact of comorbidities and social determinants on treatment effectiveness in people with hip-related pain. Clinicians and researchers working with young to middle-aged active adults with hip-related pain may use these consensus recommendations to guide, develop, test and implement individualised, evidence-based physiotherapist-led rehabilitation programmes.

Using Magneto-Inertial Measurement Units to Pervasively Measure Hip Joint Motion during Sports.

The use of wireless sensors to measure motion in non-laboratory settings continues to grow in popularity. Thus far, most validated systems have been applied to measurements in controlled settings and/or for prescribed motions. The aim of this study was to characterize adolescent hip joint motion of elite-level athletes (soccer players) during practice and recreationally active peers (controls) in after-school activities using a magneto-inertial measurement unit (MIMU) system. Opal wireless sensors (APDM Inc., Portland OR, USA) were placed at the sacrum and laterally on each thigh (three sensors total). Hip joint motion was characterized by hip acceleration and hip orientation for one hour of activity on a sports field. Our methods and analysis techniques can be applied to other joints and activities. We also provide recommendations in order to guide future work using MIMUs to pervasively assess joint motions of clinical relevance.

Predicting sport and occupational lower extremity injury risk through movement quality screening: a systematic review.

BACKGROUND: Identification of risk factors for lower extremity (LE) injury in sport and military/first-responder occupations is required to inform injury prevention strategies. OBJECTIVE: To determine if poor movement quality is associated with LE injury in sport and military/first-responder occupations. MATERIALS AND METHODS: 5 electronic databases were systematically searched. Studies selected included original data; analytic design; movement quality outcome (qualitative rating of functional compensation, asymmetry, impairment or efficiency of movement control); LE injury sustained with sport or military/first-responder occupation. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. 2 independent authors assessed the quality (Downs and Black (DB) criteria) and level of evidence (Oxford Centre of Evidence-Based Medicine model). RESULTS: Of 4361 potential studies, 17 were included. The majority were low-quality cohort studies (level 4 evidence). Median DB score was 11/33 (range 3-15). Heterogeneity in methodology and injury definition precluded meta-analyses. The Functional Movement Screen was the most common outcome investigated (15/17 studies). 4 studies considered inter-relationships between risk factors, 7 reported diagnostic accuracy and none tested an intervention programme targeting individuals identified as high risk. There is inconsistent evidence that poor movement quality is associated with increased risk of LE injury in sport and military/first-responder occupations. CONCLUSIONS: Future research should focus on high-quality cohort studies to identify the most relevant movement quality outcomes for predicting injury risk followed by developing and evaluating preparticipation screening and LE injury prevention programmes through high-quality randomised controlled trials targeting individuals at greater risk of injury based on screening tests with validated test properties.

Effects of additional anterior body mass on gait.

BACKGROUND: Gradual increases in mass such as during pregnancy are associated with changes in gait at natural velocities. The purpose of this study was to examine how added mass at natural and imposed slow walking velocities would affect gait parameters. METHODS: Eighteen adult females walked at two velocities (natural and 25 % slower than their natural pace) under four mass conditions (initial harness only (1 kg), 4.535 kg added anteriorly, 9.07 kg added anteriorly, and final harness only (1 kg)). We collected gait kinematics (100 Hz) using a motion capture system. RESULTS: Added anterior mass decreased cycle time and stride length. Stride width decreased once the mass was removed (p < .01). Added mass resulted in smaller peak hip extension angles (p < .01). The imposed slow walking velocity increased cycle time, double limb support time and decreased stride length, peak hip extension angles, and peak plantarflexion angles (p < .01). With added anterior mass and an imposed slow walking velocity, participants decreased cycle time when mass was added and increased cycle time once the mass was removed (p < .01). CONCLUSIONS: Gait adaptations may be commensurate with the magnitude of additional mass when walking at imposed slow versus natural velocities. This study presents a method for understanding how increased mass and imposed speed might affect gait independent of other effects related to pregnancy. Examining how added body mass and speed influence gait is one step in better understanding how women adapt to walking under different conditions.

Do Neuromuscular Alterations Exist for Patients With Acetabular Labral Tears During Function?

PURPOSE: To determine if contact forces and electromyography (EMG) muscle amplitudes were altered during the lunge for patients with symptomatic labral tears compared with asymptomatic control subjects. METHODS: Surface electromyography electrodes were placed over the gluteus medius, gluteus maximus, adductor longus, and rectus femoris muscles of the patients' involved limb and matched limb of asymptomatic controls. Subjects performed 3 trials of the lunge on a clinical force platform. An electrogoniometer tracked knee flexion motion during testing. Average root mean squared EMG muscle amplitudes for each muscle were calculated for the descent and ascent phases of the lunge, represented as a percentage of maximum activity (%MVIC). Peak knee flexion was calculated from the goniometer (°). The dependent variables from the force platform were lunge distance (%height), contact time (seconds), vertical impact force (%BW), and force impulse (%BW*s). Dependent variables were compared between groups using either independent samples t tests or Mann-Whitney U tests. Relations between dependent variables were assessed with Spearman Rho correlation coefficients. The level of significance was set at P ≤ .05. RESULTS: Twenty-one patients with symptomatic unilateral labral tears (14 females, 7 males) and 17 asymptomatic control subjects (11 females, 6 males) participated in this study. Average gluteus maximus EMG muscle amplitudes were reduced for symptomatic labral patients compared with asymptomatic controls during lunge ascent (51.6 ± 31.1 v 71.7 ± 36.3 [mean difference (MD): 20.1% (-2.4%, 42.6%)], P = .042). Average vertical impact force was reduced (21.8 ± 5.5 v 26.8 ± 7.3 [MD: 5.1%BW (0.84%BW, 9.3%BW)], P = .02) and average contact time (1.8 ± 0.4 v 1.5 ± 0.4 [MD: 0.27 seconds (0.006 seconds, 0.54 seconds)], P = .045) and force impulse (188.4 ± 42.4 v 162.6 ± 33.3 [MD: 25.8%BW*s (0.3%BW*s, 51.4%BW*s)], P = .042) were increased for symptomatic labral patients compared with asymptomatic controls. Vertical impact force was inversely correlated with gluteus medius muscle amplitudes during lunge descent for symptomatic labral patients (r = -0.452, P = .045). CONCLUSIONS: Our study shows that contact forces and EMG muscle amplitudes are altered during the lunge for patients with symptomatic labral tears. The presence of a relation between muscle amplitudes and contact forces suggests that targeting muscle impairments may restore function in these patients. LEVEL OF EVIDENCE: Level III, case-control study.

Changes in Gait with Anteriorly Added Mass: A Pregnancy Simulation Study.

During pregnancy, the female body experiences structural changes, such as weight gain. As pregnancy advances, most of the additional mass is concentrated anteriorly on the lower trunk. The purpose of this study is to analyze kinematic and kinetic changes when load is added anteriorly to the trunk, simulating a physical change experienced during pregnancy. Twenty healthy females walked on a treadmill while wearing a custom made pseudo-pregnancy sac (1 kg) under 3 load conditions: sac-only condition, 10-lb condition (4.535 kg added anteriorly), and 20-lb condition (9.07 kg added anteriorly), used to simulate pregnancy in the second trimester and at full-term pregnancy, respectively. The increase in anterior mass resulted in kinematic changes at the knee, hip, pelvis, and trunk in the sagittal and frontal planes. In addition, ankle, knee, and hip joint moments normalized to baseline mass increased with increased load; however, these moments decreased when normalized to total mass. These kinematic and kinetic changes may suggest that women modify gait biomechanics to reduce the effect of added load. Furthermore, the increase in joint moments increases stress on the musculoskeletal system and may contribute to musculoskeletal pain.

Lost in research translation: Female athletes are not male athletes, especially at the hip.

Altered shape of the proximal femur (cam morphology) or acetabulum (pincer morphology) is indicative of femoroacetabular impingement, which can result in hip pain and osteoarthritis of the hip. As mechanical load during growth affects the resulting bone shape, there is strong evidence in males that cam morphology develops during skeletal growth while physes are open, rather than as an adaptation after growth plates are closed (skeletal maturity). This adaptation is particularly evident in athletes who participate at elite levels prior to skeletal maturity. The research providing this evidence, however, has primarily focused on male athletes. Despite the lack of inclusion in the research, females consistently comprise two thirds of the clinical and surgical populations with structural hip pain or pathology. Knowledge gained from male-dominated cohorts may not appropriately transfer to female athletes, especially at the hip. This perspectives article briefly reviews differences between females and males in femoral and acetabular structure, hormones, timing of puberty/maturation, hypermobility, activity level and movement control-factors which affect hip structure development and loading. Without female-focused research, the application of research findings from male athletes to female athletes may lead to ineffective or even inappropriate recommendations and treatments. Thus, there is a critical need for investment in research to promote life-long hip health for females.

Legg-Calvé-Perthes disease and slipped capital femoral epiphysis: major developmental causes of femoroacetabular impingement.

Problematic femoroacetabular impingement frequently is seen following Legg-Calvé-Perthes disease (LCPD) in young children and following slipped capital femoral epiphysis (SCFE) in older children and adolescents. Although symptoms may be mild in adolescents and young adults, chondral damage following LCPD and SCFE deformity is cumulative and irreversible, which has led to a recent emphasis on the consideration of early treatment. The surgical dislocation approach and improved MRI and three-dimensional CT have revealed common patterns of deformity and structural damage. The surgical dislocation approach is a superb diagnostic tool unmatched in assessing complex dynamic impingement patterns, and it allows direct treatment of deformity through recontouring of the head and neck and, in unhealed SCFE, epiphyseal realignment. The contemporary hip-preserving management of deformity following LCPD and SCFE is changing rapidly, necessitating careful evaluation of new treatment methods.

Rehabilitation Phases, Precautions, and Mobility Goals Following Total Hip Arthroplasty.

The prevalence of total hip arthroplasty (THA) for advanced hip osteoarthritis (OA) is both increasing and shifting toward a younger average age. However, THA alone does not typically normalize function in these patients. Postoperative rehabilitation is often recommended to optimize joint motion, strength, and function. To date, there are no peer-reviewed clinical practice guidelines for postoperative rehabilitation following THA. Thus, optimal postoperative rehabilitation requires consideration of the existing literature and clinical expertise. This review article summarizes current recommendations for postoperative management of THA, including phases of rehabilitation, postoperative hip precautions, the effect of rehabilitation setting and mode of delivery on postoperative outcomes, and gait mechanics.

Can pelvic tilt cause cam morphology? A computational model of proximal femur development mechanobiology.

Cam deformity of the proximal femur is a risk factor for early osteoarthritis. While cam morphology is related to mechanical force at a formative time in skeletal growth, the specific problematic forces contributing to the development of cam morphology remain unknown. Individuals with femoroacetabular impingement syndrome exhibit an increased anterior pelvic tilt during walking, which alters their hip joint forces. This study aims to investigate the influence of altered joint force caused by anterior pelvic tilt on proximal femur epiphyseal growth and the potential association between increased anterior pelvic tilt and the development of cam morphology. A computational model is utilized to simulate the endochondral ossification in the proximal femur and predict cam formation. Cartilage growth and ossification patterns for a gait cycle with and without anterior pelvic tilt were modeled. The simulated growth results indicated an increased alpha angle (53° for typically developing to 68° for anterior pelvic tilt) and aspherical femoral head in the model with anterior pelvic tilt. We conclude that anterior pelvic tilt may be sufficient to cause the formation of the cam morphology. Identifying the critical mechanical conditions that increase the risk of cam deformity could help prevent this condition by adjusting the physical activities before skeletal maturity.

Frontal plane pelvic kinematics during high velocity running: Association with hamstring injury history.

INTRODUCTION: Hamstring injuries are the most prevalent non-contact soft tissue injury in sports, with a larger portion of injuries being recurrent. The sagittal plane running kinematics correlated to hamstring injury history has been well documented. However, analysis of frontal plane kinematics allows for observation of stability and symmetry. This study aimed to examine the frontal plane running kinematics of elite collegiate level sprinters, with and without previous hamstring injury, compared to healthy counterparts. METHODS: Thirty-nine participants performed three 50-m sprints, with three inertial measurement unit sensors placed on the pelvis: one on each iliac crest and one on the sacrum. Participants were classified based on sex, competitive status, and injury history. To investigate differences based on group classification, the data were used to analyze mediolateral motion (relative magnitude of mediolateral acceleration) and asymmetry (difference in acceleration between right and left iliac crests) during each stance phase throughout the run. RESULTS: Injured sprinters displayed significantly greater mediolateral motion and asymmetry during stances than healthy counterparts. CONCLUSIONS: This study demonstrates that frontal plane running stance dynamics are different in athletes with previous hamstring injury than healthy athletes. These athletes may benefit from rehabilitation strategies targeting postural control and stability during dynamic tasks.

Females with hip-related pain demonstrate reduced kinetics at the hip and ankle during terminal stance of gait.

BACKGROUND: Individuals with hip-related pain (HRP) commonly report pain with walking and demonstrate altered movement patterns compared to healthy controls (HCs). Individuals with HRP may attempt to reduce pain during walking by decreasing kinetics and joint forces at the hip through increased use of the ankle during pushoff. RESEARCH QUESTION: Do individuals with HRP have increased kinetics at the ankle and decreased kinetics at the hip during pushoff in gait compared to HCs, and do kinetic patterns differ between males and females with HRP? METHODS: This retrospective observational study included 42 individuals with HRP and 20 HCs. Participants completed overground gait trials at their self-selected speed while kinematics and kinetics were recorded through a motion capture system and force plates. Peak internal hip and ankle moments and hip flexion and ankle plantarflexion angular impulse during terminal stance were used in general estimating equations for comparison of group by limb interactions for males and females separately, as well as a comparison of males and females within the HRP group. RESULTS: Females with HRP demonstrated reduced hip flexion impulse on their involved limb (.070 Nm*s/kg*m) compared to female HCs (.083Nm*s/kg*m; p = .032), as well as reduced peak ankle plantarflexion moment (-.94Nm/kg*m) compared to their contralateral limb (-.99Nm/kg*m) and the involved limb of HRP males (-1.00Nm/kg*m) (p ≤ .007). There were no between-limb or between-group differences in hip or ankle peak moments or impulses in males. SIGNIFICANCE: Females with HRP show decreased kinetics at both the hip and ankle; these patterns were not identified in males. Future investigations should examine whether increasing ankle kinetics during pushoff reduces pain at the hip, as this may be a valuable clinical treatment strategy.