Hip Abduction Research Articles

Impact of model geometry and joint center locations on inverse kinematic/dynamic predictions: A comparative study of sexually dimorphic models

This work illustrates the sensitivity of demographically characteristic body segment inertial properties and subject-specific customization on model performance. One characteristic demographic, gender, and one subject-specific characteristic, hip joint center location, were represented with musculoskeletal modeling to evaluate how design decisions may alter model outputs. Generic sexually dimorphic musculoskeletal models were developed from the commonly used Rajagopal model using male and female data adapted by Dumas et al. Hip joint centers of these models were adjusted based on functional joint center testing. The kinematics and dynamics of 40 gait cycles from four subjects are predicted using these models. Two-way analysis of variance (ANOVA) was performed on the continuous time series data using statistical parametric mapping (SPM) to assess changes in kinematics/dynamics due to either choice in model (Rajagopal vs Dumas) or whether joint center adjustment was performed. The SPM based two-way ANOVA of the inverse dynamics found that differences in the Rajagopal and Dumas models resulted in significant differences in sagittal plane moments during swing (0.115 ± 0.032 Nm/kg difference in mean hip flexion moment during initial swing and a 0.077 ± 0.041 Nm/kg difference in mean hip extension moment during terminal swing), and differences between the models with and without hip joint center adjustment resulted in significant differences in hip flexion and abduction moments during stance (0.217 ± 0.055 Nm/kg increased mean hip abductive moment). By comparing the outputs of these differently constructed models with each other, the study finds that dynamic predictions of stance are sensitive to positioning of joint centers, and dynamic predictions of swing are more sensitive to segment mass/inertial properties.

Resistance training in women with myotonic dystrophy type 1: a multisystemic therapeutic avenue

Myotonic dystrophy type 1 (DM1) is a hereditary disease characterized by muscular impairments. Fundamental and clinical positive effects of strength training have been reported in men with DM1, but its impact on women remains unknown. We evaluated the effects of a 12-week supervised strength training on physical and neuropsychiatric health. Women with DM1 performed a twice-weekly supervised resistance training program (3 series of 6–8 repetitions of squat, leg press, plantar flexion, knee extension, and hip abduction). Lower limb muscle strength, physical function, apathy, anxiety and depression, fatigue and excessive somnolence, pain, and patient-reported outcomes were assessed before and after the intervention, as well as three and six months after completion of the training program. Muscle biopsies of the vastus lateralis were also taken before and after the training program to assess muscle fiber growth. Eleven participants completed the program (attendance: 98.5 %). Maximal hip and knee extension strength (p < 0.006), all One-Repetition Maximum strength measures (p < 0.001), apathy (p = 0.0005), depression (p = 0.02), pain interference (p = 0.01) and perception of the lower limb function (p = 0.003) were significantly improved by training. Some of these gains were maintained up to six months after the training program. Strength training is a good therapeutic strategy for women with DM1.

A Prospective Randomized Controlled Trial Assessing the Impact of Preoperative Combined with Postoperative Progressive Resistance Training on Muscle Strength, Gait, Balance and Function in Patients Undergoing Total Hip Arthroplasty.

The aim of this study is to investigate the effects of a preoperative combined with postoperative moderate-intensity progressive resistance training (PRT) of the operative side in patients with hip osteoarthritis (HOA) who are undergoing total hip arthroplasty (THA). The study seeks to evaluate the impact of this combined intervention on muscle strength, gait, balance, and hip joint function in a controlled, measurable, and objective manner. Additionally, the study aims to compare the outcomes of this combined intervention with those of preoperative or postoperative muscle strength training conducted in isolation. A total of 90 patients with HOA scheduled for unilateral primary THA were randomly assigned to three groups: Pre group (preoperative PRT), Post group (postoperative PRT), and Pre& Post group (preoperative combined with postoperative PRT) focusing on hip flexion, extension, adduction, and abduction of operated side. Muscle strength, gait parameters, balance, and hip function were assessed at specific time points during a 12-month follow-up period. All three groups showed significant improvements in muscle strength, with the Pre& Post group demonstrating the most pronounced and sustained gains. Gait velocity and cadence were significantly improved in the Pre& Post group at 1-month and 3-month postoperative follow-ups compared to the other groups. Similarly, the Pre& Post group exhibited superior balance performance at 3-month and 12-month postoperative follow-ups. The Harris Hip Score also showed better outcomes in the Pre& Post group at all follow-up intervals. Preoperative combined with postoperative moderate-intensity PRT in HOA patients undergoing THA led to superior improvements in muscle strength, gait, balance, and hip joint function compared to preoperative or postoperative PRT alone. This intervention shows significant promise in optimizing postoperative rehabilitation and enhancing patient outcomes following THA.

The Relationship Between Functional Movement Screening and Joint Range of Motion, Y-Balance Test and Countermovement Jump in Amateur Soccer Players

This study aimed to investigate the relationship between a functional movement screening (FMS) test and joint range of motion (ROM), balance (YBT), and countermovement jump (CMJ) performance in amateur soccer players. A study was conducted with 25 male amateur soccer players to assess their physical abilities using various tests. The tests included FMS, YBT, CMJ, ROM for shoulder extension, hip abduction, hip external rotation, and ankle dorsi/plantar flexion. Pearson’s correlation test was used to examine the association between the variables. A significant positive correlation between the FMS and CMJ (r=0.424, p

Hip Abductor Muscle Strength Recovery: A Comparison Between Joint Replacement Surgery and Internal Fixation Surgery.

Introduction Proximal femoral fractures are common fractures of the hip that are considered a major healthcare concern globally; these include subtrochanteric, intertrochanteric, and theneck of the femur fractures. Internal fixation surgery and joint replacement surgery are the two most common intervention techniques used to treat these fractures. Consequently, weakness in the hip abductor muscle post-surgery may lead to implant loosening, necessitating revision of the surgery. In light of this, this study aimed to compare hip abductor strength recovery outcomes between joint replacement surgery and internal fixation surgery. Methodology A comparative study was performed over six months at the Department of Orthopaedics and Physiotherapy. Based on the inclusion and exclusion criteria and anticipating potential dropouts, a total of 56 patients were included in thestudy, and their hip abductor strength was measured using a sphygmomanometer. The patients were classified into two groups: Group A or Group B as per the type of hip surgery. Group A included 29 patientswho underwent joint replacement surgeries involving either cemented or uncemented total hip arthroplasty (THA) or hip hemiarthroplasty (HHA). Group B comprised 27 patientswho were operated on using either proximal femoral nail (PFN) or dynamic hip screw (DHS). Results The cohort consisted of 36 males and 20 females, with a mean age of51.71 years. The overall mean value of hip abductor muscle strength at postoperative day (POD) three in the internal fixation group was 65.06 ±5.98, which progressed to 107.51 ±24.76 after six months; in the joint replacement surgery group, it was 70.03 ±12.46 at POD three, which progressed to 113.11 ±21.27 after six months. The age-wise distribution demonstrated that the patients in the age group of 18-50 years demonstrated progressive results: from 65.33 ±4.9 at POD three to 105.95 ±22.71 after six months in the internal fixation group;from 66.82 ±7.72 at POD three to 109.59 ±22.54 after six months in the joint replacement group. Moreover, patients aged above 50 yearsshowed progression from 64.80 ±6.98 at POD three to 103.33 ±27.30 after six months in the internal fixation group, and from 69.58 ±14.75 at POD three to 108.22 ±20.62 after six months in the joint replacement group. Conclusions Our findings revealed thatjoint replacement surgery resulted in greater improvements in the hip abductor muscle strength compared to internal fixation surgery in the immediate postoperative period and during follow-ups. Additionally, younger patients exhibited better strength-related outcomes in comparison to the elderly population regardless of the type of surgery.

No sign of weakness: a systematic review and meta-analysis of hip and calf muscle strength after anterior cruciate ligament injury

ObjectiveWe aimed to determine hip and lower-leg muscle strength in people after ACL injury compared with an uninjured control group (between people) and the uninjured contralateral limb (between limbs).DesignSystematic review...

Observe, Practice, and Improve? Enhancing Sidestep Cutting Execution in Talented Female Soccer Players: A Four-Week Intervention Program With Video Instruction.

Nijmeijer, EM, Kempe, M, Elferink-Gemser, MT, and Benjaminse A. Observe, practice and improve? Enhancing sidestep cutting (SSC) execution in talented female soccer players: A four-week intervention program with video instruction. J Strength Cond Res 38(8): e430-e439, 2024-Implicit learning has the potential to improve movement execution and reduce injury risk. Previous research showed beneficial effects of short-term interventions with implicit learning in male athletes. However, research on long-term interventions in female athletes is lacking. The aim of this study was to examine the effects of a 4-week intervention with video instruction on movement execution of SSC, a task that is highly related with anterior cruciate ligament (ACL) injury risk, in female athletes. Twenty talented adolescent female soccer players were part of the control (CTRL, n = 10) or video instruction (VIDEO, n = 10) group. All subjects practiced 4 weeks and received general task instructions. In addition, the VIDEO group received expert video instruction during practice. Lower extremity kinematics and kinetics and vertical ground reaction force of SSC were examined during baseline, immediate post, and 1-week retention tests. After nonlinear registration, differences between each subject and the expert she had seen were determined. These differences were analyzed with SPM1D 2-way ANOVA. No interaction effects between time and group were found ( p > 0.05). Main effects of time were found in the frontal plane. In particular, smaller deviations of subjects compared with the seen expert of the knee adduction ( p = 0.005, 97.9-100% stance phase [SP]) and hip abduction ( p = 0.005, 11.5-13.8% SP) and adduction ( p < 0.001, 33.4-87.7% SP) moments were found in immediate post compared with baseline. These frontal plane short-term improvements, replicating earlier findings in both sexes, may lower ACL injury risk. The large observed interindividual differences over time may have concealed the long-term effects of video instruction at the group level.

Gait Compensation among Children with Non-Operative Legg-Calvé-Perthes Disease: A Systematic Review.

A systematic electronic search was performed using MEDLINE, CINAHL, Embase, BIOSIS, and the Cochrane Library to identify studies published from inception up until December 2023. An adapted Downs and Black checklist was utilised to assess methodological quality and project risk of bias. Percentage agreement and nominal kappa statistics with bootstrapped bias-corrected 95% confidence intervals (CIs) were used. A comprehensive literature search revealed 277 citations for review, of which 210 studies entered full-text screening. In total, eight studies met the inclusion criteria for quality assessment by two independent reviewers. The results revealed variations in data quality, with scores ranging from 12 to 17 due to missing information related to subject characteristics, biomechanical model, and power calculation. This review reveals common compensation strategies associated with walking among non-operative children with Perthes disease such as Trendelenburg gait due to weakness of the hip abductor muscle.

Dependence on visual information in patients with ACL injury for multi-joint coordination during single-leg squats: a case control study.

The influence of vision on multi-joint control during dynamic tasks in anterior cruciate ligament (ACL) deficient patients is unknown. Thus, the purpose of this study was to establish a new method for quantifying neuromuscular control by focusing on the variability of multi-joint movement under conditions with different visual information and to determine the cutoff for potential biomarkers of injury risk in ACL deficient individuals. Twenty-three ACL deficient patients and 23 healthy subjects participated in this study. They performed single-leg squats under two different conditions: open eyes (OE) and closed eyes (CE). Multi-joint coordination was calculated with the coupling angle of hip flexion, hip abduction and knee flexion. Non-linear analyses were performed on the coupling angle. Dependence on vision was compared between groups by calculating the CE/OE index for each variable. Cutoff values were calculated using ROC curves with ACL injury as the dependent variable and significant variables as independent variables. The sample entropy of the coupling angle was increased in all groups under the CE condition (P < 0.001). The CE/OE index of coupling angle variability during the descending phase was higher in ACL deficient limbs than in the limbs of healthy participants (P = 0.036). The CE/OE index of sample entropy was higher in the uninjured limbs of ACL deficient patients than in the limbs of healthy participants (P = 0.027). The cutoff value of the CE/OE index of sample entropy was calculated to be 1.477 (Sensitivity 0.957, specificity 0.478). ACL deficient patients depended on vision to control multiple joint movements not only on the ACL deficient side but also on the uninjured side during single leg squat task. These findings underscore the importance of considering visual dependence in the assessment and rehabilitation of neuromuscular control in ACL deficient individuals.

Automated evaluation of hip abductor muscle quality and size in hip osteoarthritis: Localized muscle regions are strongly associated with overall muscle quality

Limited information exists regarding abductor muscle quality variation across its length and which locations are most representative of overall muscle quality. This is exacerbated by time-intensive processes for manual muscle segmentation, which limits feasibility of large cohort analyses. The purpose of this study was to develop an automated and localized analysis pipeline that accurately estimates hip abductor muscle quality and size in individuals with mild-to-moderate hip osteoarthritis (OA) and identifies regions of each muscle which provide best estimates of overall muscle quality.Forty-four participants (age 52.7 ± 16.1 years, BMI 23.7 ± 3.4 kg/m2, 14 males) with and without mild-to-moderate radiographic hip OA were recruited for this study. Unilateral hip magnetic resonance (MR) images were acquired on a 3.0 T MR scanner and included axial T1-weighted fast spin echo and 3D axial Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL-IQ) spoiled gradient-recalled echo (SPGR) with multi-peak fat spectrum modeling and single T2* correction. A three dimensional (3D) V-Net convolutional neural network was trained to automatically segment the gluteus medius (GMED), gluteus minimus (GMIN), and tensor fascia lata (TFL) on axial IDEAL-IQ. Agreement between manual and automatic segmentation and associations between axial fat fraction (FF) estimated from IDEAL-IQ and overall muscle FF were evaluated.Dice scores for automatic segmentation were 0.94, 0.87, and 0.91 for GMED, GMIN, and TFL, respectively. GMED, GMIN, and TFL volumetric and FF measures were strongly correlated (r: 0.92–0.99) between automatic and manual segmentations, where all values fell within the 95% limits of agreement of [−9.79 cm3, 17.43 cm3] and [−1.99%, 2.89%], respectively. Axial FF was significantly associated with overall FF with the strongest correlations at 50%, 50%, and 65% the length of the GMED, GMIN, and TFL muscles, respectively (r: 0.93–0.97). An automated and localized analysis can provide efficient and accurate estimates of hip abductor muscle quality and size across muscle length. Specific regions of the muscle may be used to estimate overall muscle quality in an abbreviated evaluation of muscle quality.

Surgical Treatment and Outcomes for Gluteal Tendon Tears.

Gluteus medius and minimus tears, or hip abductor tendon tears, are increasingly identified as a source of lateral hip pain. Once underappreciated and undertreated, they are now recognized as a cause of greater trochanteric pain syndrome and a pathology amenable to both nonoperative and operative modalities. This review summarizes relevant anatomy, clinical presentation, and treatment options for gluteus medius tears, focusing on surgical options. When surgical intervention is indicated, repair, reconstruction, or tendon transfer may be considered. Open and endoscopic repair techniques demonstrate similar outcomes with improvements in patient-reported outcomes and low complication and retear rates for both partial and full thickness tears. Variations in fixation construct and graft augmentations have been described, though clinical evidence remains limited to support specific techniques. Gluteus maximus transfer via open approach is a salvage option for the severely atrophied, retracted, or revision gluteus tendon; however, persistent limitations in abduction strength and gait abnormalities are common. Emerging evidence continues to evolve our understanding of surgical decision-making for gluteus tendon tears. The current literature supports either open or endoscopic repair techniques and open tendon transfer as a salvAage option. Further study is needed to determine the optimal fixation construct, the role of graft augmentation, and patient-related factors that influence postoperative outcomes.

A New Flexometric Method to Evaluate Range of Movement: A Validity and Reliability Study

Hip range of movement (ROM) impairments could affect individuals’ quality of life. The aim of this study is to describe a new flexometric method (FM) as a means to estimate hip ROM and to determine its concurrent validity and inter-rater and intra-rater reliability. Hip ROM was measured by performing the straight leg raise test (SLR) and hip abduction test (HA). The WIMU system is the gold standard. ROM was calculated in degrees using a trigonometric function based on values derived from measurements with a flexometer. The SLR and the HA showed high concurrent validity and good inter- and intra-rater reliability with an interclass correlation coefficient value that was at all times &gt; 0.9. The minimal detectable change at the 90% confidence level for inter- and intra-rater reliability was equal to or greater than 5.7° in SLR-Right, 5.6° in SLR-Left, 5.1° in HA, 6.3° in SLR-Right, 4.9° in SLR-Left, and 5.4° in HA, respectively. This study suggests that the FM is a valid and reliable tool for assessing hip ROM. Due to its convenience and cost-effectiveness, this method could be widely used to measure the ROM of several joints in field-based tests.

Biomechanical Comparison of Pediatric Female Ballet Dancers With and Without Pain

BACKGROUND: Across all genres of dance, studies have reported musculoskeletal injury in 20-84% of dancers with 95% reporting a history of musculoskeletal pain. Compared to other dance styles, ballet dancers specifically are most affected by musculoskeletal injuries. The purpose of this study is to compare movement patterns and muscle activity in pediatric female pre-professional dancers with and without self- reported pain, using the Patient-Reported Outcomes Measurement Information System pediatric numeric rating scale. We hypothesize dancers reporting pain will exhibit compensatory strategies, such as asymmetrical movement patterns and muscle activity, across a series of ballet movements. METHODS: A total of 55 female ballet dancers who train en pointe were seen for testing (age 14.4±1.9 years), with 34 dancers (62%) self-reported pain in the 7 days preceding testing. Biomechanical testing, performed in pointe shoes, included performance of static (5 classical ballet positions) and dynamic ballet movements (développé, arabesqué and grand jeté) while instrumented with surface electromyography (EMG) to capture muscle activity and inertial measurement (IMU) dual sensors on the trunk and lower extremities to capture movement patterns. The experimental setup allowed for measurement of trunk and lower extremity muscle activity, as well as trunk, hip, knee, and ankle joint angles in the sagittal, coronal, and transverse planes. Student’s t-test was used to compare the pain and no pain groups across all variables with statistical significance set to α=0.05. RESULTS: Movement patterns and EMG differences were seen between groups. During first and third positions, the right (non-barre sided) leg demonstrated less external knee rotation in the pain group (p≤0.05). In fifth position, the left (barre-sided) leg exhibited increased ankle flexion (p=0.048), reduced hip abduction (p=0.027), and reduced knee adduction (p=0.026) in the pain group. The pain group exhibited decreased trunk flexion/extension range-of-motion during the grand jeté (p=0.004), and increased trunk rotation range-of-motion when performing the arabesqué en pointe (p=0.034). Rectus femoris activation was reduced for the pain group on the left leg in fifth position (p&lt;0.03). The up leg in the pain group during the développé (flat) showed increased hamstring activation (p=0.04). CONCLUSION: Ballet dancers with pain exhibited differences in movement patterns while performing certain ballet movements, notably during fifth position, grand jeté, and arabesqué (en pointe). Additionally, dancers with pain exhibited reduced rectus femoris activation in fifth position and increased hamstring activation on the working leg during the développé (flat). Future work should investigate how movement patterns and muscle activation in ballet dancers vary by location and severity of reported pain.

Effects of Ankle Position While Performing One- and Two-Leg Floor Bridging Exercises on Core and Lower Extremity Muscle Recruitment.

Given there are no known studies which have examined multiple lower extremity muscles between different ankle positions during bridging activities, the objective was to assess how employing two different ankle positions (PF versus DF) while performing five common bridging exercises (three bipedal and two unipedal) used in rehabilitation and athletic performance affect core and select lower extremity muscle EMG recruitment. Twenty healthy subjects performed a 5 s isometric hold during five two- and one-leg bridge exercises: (1) on right leg with left knee to chest (1LB-LFlex); (2) on right leg with left knee extended (1LB-LExt); (3) standard two-leg bridge (2LB); (4) two-leg bridge with resistance band around knees (2LB-ABD); and (5) two-leg bridge with ball between knees (2LB-ADD). Surface electromyographic (EMG) data were collected using a Noraxon Telemyo Direct Transmission System from fourteen muscles: (1) three superficial quadriceps (VM, VL, and RF); (2) three hip abductors (TFL, GMED, and GMAX); (3) medial hamstrings (ST) and lateral hamstrings (BF); (4) hip adductors (ADD); (5) erector spinae (ES); (6) latissimus dorsi (LATS); (7) upper rectus abdominis (RA); and (8) external oblique (EO) and internal oblique (IO). EMG data were normalized by maximum voluntary isometric contractions (MVICs). A paired t-test (p < 0.01) was used to assess differences in normalized mean EMG activities between DF and PF for each exercise. EMG activities were significantly greater in DF than PF for the (a) VM, VL, and RF during 1LB-LFlex; (b) ADD during 1LB-LFlex, 1LB-LExt; (c) EO during 1LB-LFlex; and (d) IO during 1LB-LFex. In contrast, EMG activities were significantly greater in PF than DF for ST and BF during all five bridge exercises. Bridging with PF (feet flat) was most effective in recruiting the hamstrings, while bridging with DF (feet up) was most effective in recruiting the quadriceps, hip adductors, and internal and external obliques.

Anatomical and topographic features of the gluteal muscle group of extensors and rotators of the hip joint in a Maine Coon cat

The article presents the anatomical features of the gluteal group of extensors and supinators of the hip joint in a Maine Coon cat, which are absent in the available literature. The Maine Coon is the largest of the numerous breeds of domestic cats. To date, the anatomy of cats, and even more so the age, sex, breed, and species characteristics remain poorly understood, while the study of the specific anatomical features of the pelvic limb muscles in animals is one of the urgent tasks in the field of comparative anatomy and practical veterinary medicine. We have established that the muscles of the gluteal extensor group belong to different types of muscles: the middle gluteal is dynamic, the additional and deep gluteal, the pear–shaped is dynamostatic, with appropriate functional abilities. The research was carried out at the Department of Anatomy and Histology of Animals named after Professor A.F. Klimov, Moscow State Academy of Veterinary Medicine and Biotechnology – MBA named after K.I. Scriabin."The sectional material – pelvic limbs (n=8), selected from a domestic cat, without external signs of musculoskeletal pathologies, served as a material for research. Methods of fine macro- and microanatomic dissection were used, followed by functional analysis of the studied structures and skeletotopic projection of points of attachment of muscle parts. On the basis of the conducted research, we have established the skeleto-topical features of the anatomical formations on the pelvic and femur bones. It has been convincingly shown that the main extensor of the hip joint in the Maine Coon is the gluteus medius muscle. It is the most powerful among the gluteal muscles and belongs to the dynamic type in its internal structure. At the same time, the additional gluteus muscle, being a muscle of the dynamo-static type, performs a more static function of the joint, that is, when it is extended, it holds the joint in this position for a longer time. The piriformis and deep gluteus muscles, anchored by the bases at different levels, are synergists in hip abduction.

Exploring the relationship between lower limb strength, strength asymmetries, and curvilinear sprint performance: Findings from a pilot study.

Team sports involve various sprinting actions, including curvilinear sprints, yet their neuromuscular factors have been understudied. The aim of this cross-sectional study was to investigate the relationship between lower limb muscle strength, strength asymmetries, linear sprint and curvilinear sprint performance. At two visits 12 male (age: 24.8 ± 4.7 years, height: 1.82 ± 0.06 m, body mass: 80 ± 6.58 kg) and 6 female (age: 20.8 ± 1.33 years, body height: 1.60 ± 0.02 m, body mass: 55.3 ± 2.88 kg) student-athletes completed isometric strength measurements of the knee flexors (KF), knee extensors (KE), hip abductors (HABD), hip adductors (HADD), as well as linear sprint and curvilinear sprint to the right and left. Sprint split times over 30 m (t30) were measured and curvilinear sprint split time deficits (t30deficit) and inter-limb strength asymmetries were calculated. Very large negative correlations were observed between HADD and HABD strength on one side and t30 of curvilinear sprint to the left (r = -0.75 and -0.71; p < 0.001) and right (ρ = -0.81 and -0.70; p < 0.001) on the other. The regression model consisting of HADD, HABD, and KF explained 76% and 67% of the variance in left and right curvilinear sprint t30, respectively. Similarly, 59% of the left curvilinear sprint t30deficit variance was explained by the HABD and KF strength. High inter-limb HABD strength symmetry was related to better left and right curvilinear sprint t30 (r = 0.71 and ρ = 0.75, p < 0.001). These results highlight the pivotal role of hip strength for curvilinear sprint speed, and emphasize the need of symmetrical HABD muscle strength to optimize neuromuscular function during curvilinear sprint.

Effect of adding short foot exercise to hip and knee focused exercises in treatment of patients with patellofemoral pain syndrome: a randomized controlled trial

BackgroundPatellofemoral pain syndrome is considered a common cause of anterior knee pain that could disturb function and limit daily activities. The purpose of the study was to investigate the effect of adding short foot exercise on pain, function, balance, and hip abductors, and quadriceps muscles strength in the treatment of patients with patellofemoral pain syndrome.MethodsTwenty-eight male and female patients with patellofemoral pain syndrome with age ranged from 18 to 35 years old participated in this study. They were equally and randomly assigned into two groups; the study group which received short foot exercise in addition to hip and knee exercises (n = 14) and thecontrol group which received hip and knee exercises only (n = 14). Participants received their interventions during 6 consecutive weeks (12 sessions). Pain intensity, function, abductors quadriceps muscle strength, and balance were assessed using the Visual Analog Scale, anterior knee pain scale (AKPS), hand-held dynamometer, and the Biodex Balance System respectively. All measurements were taken before and after 6 weeks of intervention in both groups. Multivariate analysis of variance was performed to compare the within and between groups effects for measured variables.ResultsThe within-group comparison showed significant improvement in pain severity, function, balance, and hip abductors, and quadriceps muscles strength in both groups post-treatment compared with pre-treatment. Between groups analysis, however, showed no significant statistical difference between both groups in all variables, except in pain, function, and mediolateral stability which showed better improvement compared to the control group.ConclusionsAdding short foot exercise to hip and knee exercises improved pain, function, and mediolateral stability in patients with patellofemoral pain syndrome.Trial registrationclinicaltrials.gov. NO: NCT05383781. Date 19/ 5/2022.

Accuracy of conventional motion capture in measuring hip joint center location and hip rotations during gait, squat, and step-up activities

Accurate measurements of hip joint kinematics are essential for improving our understanding of the effects of injury, disease, and surgical intervention on long-term hip joint health. This study assessed the accuracy of conventional motion capture (MoCap) for measuring hip joint center (HJC) location and hip joint angles during gait, squat, and step-up activities while using dynamic biplane radiography (DBR) as the reference standard. Twenty-four young adults performed six trials of treadmill walking, six body-weight squats, and six step-ups within a biplane radiography system. Synchronized biplane radiographs were collected at 50 images per second and MoCap was collected simultaneously at 100 images per second. Bone motion during each activity was determined by matching digitally reconstructed radiographs, created from subject-specific CT-based bone models, to the biplane radiographs using a validated registration process. Errors in estimating HJC location and hip angles using MoCap were quantified by the root mean squared error (RMSE) across all frames of available data. The MoCap error in estimating HJC location was larger during step-up (up to 89.3 mm) than during gait (up to 16.6 mm) or squat (up to 31.4 mm) in all three anatomic directions (all p < 0.001). RMSE in hip joint flexion (7.2°) and abduction (4.3°) during gait was less than during squat (23.8° and 8.9°) and step-up (20.1° and 10.6°) (all p < 0.01). Clinical analysis and computational models that rely on skin-mounted markers to estimate hip kinematics should be interpreted with caution, especially during activities that involve deeper hip flexion.

Cross-Education Effects of Hip Strengthening in Individuals with Chronic Ankle Instability

ABSTRACT Introduction/Purpose Chronic ankle instability (CAI) is associated with reduced balance, lumbopelvic stability, and hip strength. Accordingly, hip strengthening is an effective intervention for individuals with CAI. Cross-education through unilateral exercise is also beneficial to individuals with CAI, but cross-education effects of hip strengthening remain unknown. The purpose of this study was to determine cross-education effects of hip strengthening in individuals with CAI. Methods Thirty individuals with CAI were randomized into control (CON) and hip strengthening (HIP) groups. Baseline and postintervention tests of the uninvolved limb included lumbopelvic stability (unilateral hip bridge), handheld dynamometry (isometric hip extension, abduction, and external rotation strength), and balance (Star Excursion Balance Test (SEBT) in anterior, posterolateral (PL), and posteromedial directions). After baseline testing, HIP completed progressive hip strengthening of the involved limb three times per week for 8 wk, and CON did not. Repeated-measures analyses of variance assessed the effects of group and time on each outcome. Each group’s mean changes from baseline to postintervention were assessed via effect sizes. Statistical significance was set a priori at P &lt; 0.05. Results Of the 30 participants enrolled, 10 did not complete the postintervention data collection. Multiple imputations estimated missing data, and an intention-to-treat analysis was conducted. There were no significant group-by-time interactions for hip strength, balance, or lumbopelvic stability. HIP exhibited moderate effect sizes for SEBT-PL and hip bridge. All other effect sizes were small or negligible. Conclusions We did not identify a clear cross-education effect following unilateral hip strengthening in a cohort with CAI. Examination of baseline to postintervention effect sizes indicate a potential trend toward improved balance and lumbopelvic stability of the HIP group.

Ankle dorsiflexion range of motion and hip abductor strength can predict Lower Quarter Y-Balance Test performance in healthy males

ObjectivesThe aim of the study was to assess whether strength and range of motion (ROM) of the hip and ankle are the factors determining performance in the Lower Quarter Y-Balance test (YBT-LQ). DesignCross-sectional study. Participants66 healthy males (age: 25.2±6.8 years) participated in this study. Main outcome measuresParticipants underwent assessments of ankle dorsiflexion (DF) ROM, hip internal rotation (IR) ROM, external rotation (ER) ROM and isometric strength of hip abductor (ABD), extensor (EXT) and external rotators (ERS) muscles together with YBT-LQ for both legs. A forward 2-steps multiple linear regression analysis was conducted to examine the relationship between the predictor variables and the criterion variable. ResultsAnkle DF ROM predicted anterior (ANT) reach (R2 = 0.49; R2 = 0.33; p < 0.001). The model with hip ABD strength and ankle DF ROM explained posteromedial (PM) reach variance for stance leg (R2 = 0.35; p < 0.001), while only hip ABD strength was included for kicking leg (R2 = 0.19; p = 0.007). The model with ankle DF ROM and hip ABD strength explained posterolateral (PL) reach for stance leg (R2 = 0.41; p < 0.001). Hip ABD was the only predictor for kicking leg PL reach (R2 = 0.15; p < 0.001). YBT-LQ composite score was explained by ankle DF ROM and hip ABD strength for both legs (R2 = 0.44; p < 0.001) and (R2 = 0.25; p = 0.002). ConclusionHip ABD strength and ankle DF ROM can determine performance in the YBT-LQ. Strength of hip EXT, ERS as well as ROM of hip IR and ER did not predict YBT-LQ performance.