Sex differences in trunk, pelvis, hip and knee kinematics and eccentric hip torque in adolescents

Patellofemoral pain syndrome in children and adolescents: A cross-sectional study

OBJECTIVES

To assess the prevalence and associated factors of Patellofemoral Pain Syndrome (PFPS) in children and adolescents.

METHOD

A population-based cross-sectional study was conducted with children and adolescents aged 10 to 18 years, who presented a history of peripatellar and/or retropatellar pain, attending elementary or high school in urban public schools in Natal, Brazil. The sample size was calculated based on a minimum outcome prevalence of 22%.

RESULTS

A prevalence of 24.7% of PFPS was found. There was a positive association of PFPS with active students (p < 0.01; PR: 2.5; CI: 1.4-4.5), low functional capacity (p < 0.01; PR: 8.0; CI: 5.0-12.8), and those classified as pubertal (p < 0.03; PR: 1.8; CI: 1.0-3.2).

CONCLUSION

There was a considerable prevalence of PFPS in children and adolescents, as well as an association between the level of sexual maturation and adjustable determinants, such as the level of physical activity and low functional capacity in this group.

Prevalence and Demographic Distribution of Hypermobility in a Random Group of School-Aged Children in Nigeria

BACKGROUND

The purpose of this study was to determine the prevalence of hypermobility in randomly selected healthy children, without previous trauma or disease process affecting the joints and whether other demographic variables (age, sex, BMI) had an impact on Beighton scores and range of motion (RoM) in children between 6 and 10 years of age.

RESULTS

286 children were included; 27.3% of them had a Beighton score ≥7/9 and 72% would be classified hypermobile if we had used a Beighton cut-off score ≥4/9. Prevalence declined with increasing age. Girls were more often hypermobile (34%) than boys (20%) and this was mainly caused by increased RoM in the knees. Positive scores of finger items of the Beighton were more common than on the other items, leading to a high prevalence of peripheral hypermobility. Localized hypermobility was only found in the fifth MCP joint. A total of 15% of the children with normal mobility reached 20 excess degrees RoM of the left and right fifth MCP. Pain was present in 12 of the 239 children but was not linked to the level of mobility.

CONCLUSION

Hypermobility is the rule in this pain-free population of children with GJH.

Dynamic knee valgus prevalence in children and its association with pain intensity, foot mobility, and sex- A cross-sectional study

Introduction

Knee pain can impact the performance of activities and sports participation in children. Dynamic knee valgus is a movement pattern commonly related to health conditions that may be associated with sex and foot kinematics in children.

Objective

To assess the prevalence of dynamic knee valgus and its relationship with foot mobility, sex, and knee pain in children.

Method

A cross-sectional observational study was carried out with 144 children (10-18 years old). The pain level was investigated using the Visual Analog Pain Scale and categorized into no pain/minor pain (≤2 cm), moderate pain (3-4,9 cm), and severe pain (≥5.0 cm). Foot mobility was assessed using the adapted navicular drop test and categorized into poor/adequate foot mobility (0.0 cm-0.9 cm) and greater foot mobility (≥1.0 cm). The dynamic knee valgus presence was checked using the step-down test. The association analysis was performed using simple tabulation considering the cluster effect. The Prevalence Ratios and the respective confidence intervals (95%) were estimated from Multiple Poisson Regression with robust variance. A significance level of 5% was adopted.

Results

The dynamic knee valgus prevalence was 26.3% and 26.9% in the right and left lower limbs, respectively. Females presented greater dynamic knee valgus frequency in the left lower limb than males. The dynamic knee valgus presence in males was associated with foot mobility in right (p = 0.001) (Prevalence Ratio: 9.33 Confidence Interval: 2.93-29.72) and left lower limbs (p = 0.003) (Prevalence Ratio: 6.25 Confidence Interval: 1.7-22.62).

Conclusion

Male and female children showed different relationships of the analyzed factors, suggesting that characteristics related to sex may impact the aspects linked to dynamic knee in children.

Females with knee osteoarthritis use a detrimental knee loading strategy when squatting

BACKGROUND

The purpose of this study was to identify sex differences in lower limb kinematics, kinetics, and muscle activation patterns between individuals with osteoarthritis and healthy controls during a two-legged squat.

METHOD

Thirty OA (15 females) and 30 healthy (15 females) participants performed three 2-legged squats. Sagittal and frontal plane hip, knee, and ankle kinematics and kinetics were calculated. Two-way ANOVAs (Sex X OA Status) were used to characterize differences in squatting strategies between sexes and between those with and without knee OA.

RESULTS

A greater decrease in sagittal hip, knee, and ankle range of motion and knee joint power was observed in the OA participants compared to the healthy controls. Females with OA had significantly reduced hip and knee adduction angles compared to the healthy females and males with OA. Females also had decreased hip power, hip flexion, and hip adduction moments and knee adduction moments compared to their male counterparts, with the greatest deficits observed in the females with OA. Females with OA also had the highest magnitude of muscle activation for the quadriceps, hamstrings, and gastrocnemius throughout the squat, while males with OA showed increased activation of the vastus lateralis and medial gastrocnemius compared to the healthy males.

CONCLUSIONS

OA significantly altered biomechanics and neuromuscular control during the squat, with males employing a hip-dominant strategy, allowing them to achieve a greater lower limb range of motion.

Hip and ankle strength and range of motion in female soccer players with dynamic knee valgus

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p< 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p< 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p< 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation.

Hip Abductor Rate of Torque Development as Opposed to Isometric Strength Predicts Peak Knee Valgus During Landing: Implications for Anterior Cruciate Ligament Injury

Peak knee valgus has been shown to predict anterior cruciate ligament injury. The purpose of the current study was to compare peak rate of torque development (RTD) to peak isometric torque as a predictor of peak knee valgus during landing. Twenty-three healthy females participated. Hip abductor muscle performance was quantified using 2 types of isometric contractions: sustained and rapid. Peak isometric torque was calculated from the sustained isometric contraction. Peak RTD was calculated from the rapid isometric contraction (0-50 and 0-200 ms after force initiation). Kinematic data were collected during the deceleration phase of a double-leg drop jump task. Linear regression was used to assess the ability of hip abductor muscle performance variables to predict peak knee valgus. Increased peak RTD during the 0 to 50 milliseconds window after force initiation was found to significantly predict lower peak knee valgus (P = .011, R2 = .32). In contrast, neither peak RTD from 0 to 200 milliseconds after force initiation window (P = .45, R2 = .03) nor peak isometric torque (P = .49, R2 = .03) predicted peak knee valgus. The inability of the hip abductors to rapidly generate muscular force may be more indicative of "at-risk" movement behavior in females than measures of maximum strength.

Simple verbal instructions are able to improve quality of movement during the lateral step-down test in healthy females

INTRODUCTION

Altered movement patterns during weight-bearing activities have been associated with knee injuries and can be clinically assessed using the lateral step-down test (LSD). It is possible that verbal feedback can improve movement patterns, but it remains unknown whether verbal feedback can improve movement quality during the LSD.

PURPOSE

To investigate whether verbal feedback can immediately improve visual movement quality and trunk, pelvis and lower limb kinematics in healthy females during the LSD.

METHODS

34 healthy females were assessed visually and with 3D kinematics while performing the LSD. Participants were divided into Good Movement Group (GG; n = 18) and Poor Movement Group (PG; n = 16) based on the LSD score. The feedback involved verbal instructions aimed at improving trunk, pelvis, hip and knee alignment during the test. Lower limb flexibility and strength were assessed for group comparisons and to investigate associations between all variables. Data analyses were performed using repeated-measures two-way ANOVAs and Spearman correlation tests.

RESULTS

Feedback immediately improved movement quality, especially in participants of the GG [mean difference (MD) = 2.2 points; P < 0.001]. The PG showed greater pelvic drop (MD = 5.1°; P = 0.012), greater hip adduction (MD = 5.4°; P = 0.028) and less hip flexion (MD = 8.4°; P = 0.016) than the GG. Quality of movement had positive correlations with pelvic drop (r = 0.39; P = 0.02), hip adduction (r = 0.45; P = 0.01) and hip flexion (r = 0.49; P < 0.01) kinematics.

CONCLUSIONS

Verbal feedback improved movement quality during the LSD in healthy females. Females with worst movement quality showed greater pelvic drop and hip adduction, which are often found in individuals with knee disorders.

Gender-specific difference of in-vivo kinematics in patients with unilateral total hip arthroplasty

PURPOSE

Asymmetric gait patterns are known to persist in patients with unilateral total hip arthroplasty (THA). Little is known about the effect of gender on gait asymmetry. This study aimed to determine whether gait asymmetry differs between genders in unilateral THA patients and can be explained by component positioning.

METHODS

23 female and 10 male unilateral THA patients were included. Asymmetric hip kinematics during gait and component positioning were quantified using a combined computed tomography-based modelling and dual fluoroscopic imaging system. Multiple regression was performed to examine the unique and mediated contribution of gender to observed gait asymmetry.

RESULTS

Female and male patients differed most significantly in frontal plane gait asymmetry (p = 0.001) and bilateral difference of vertical femoral offset (p = 0.048). Compared with the native hip, the implanted hip exhibited significantly increased adduction (p = 0.007) in females but significantly increased abduction (p = 0.001) in males. The stem head of the implanted hip was more superiorly positioned compared to the native femoral head in female but more inferiorly positioned in male. Gender accounted for 41.5% variance of frontal plane gait asymmetry and was partially mediated by the bilateral difference of vertical femoral offset.

CONCLUSIONS

Female unilateral THA patients exhibited significantly increased adduction in the implanted hip compared to the native hip, which is partially attributable to a more superiorly positioned femoral stem centre of rotation. The understanding of gender-specific differences of kinematic patterns may benefit female patients through targeted preoperative planning and postoperative rehabilitation.

Kinematic and kinetic differences between military patients with patellar tendinopathy and asymptomatic controls during single leg squats

BACKGROUND

Knee valgus alignment has been associated with lower-limb musculoskeletal injury. This case-control study aims to: assess biomechanical differences between patients with patellar tendinopathy and healthy controls.

METHODS

43 military participants (21 cases, 22 controls) were recorded using 3D-motion capture performing progressively demanding, small knee bend, single leg and single leg decline squats. Planned a priori analysis of peak: hip adduction, knee flexion, pelvic tilt, pelvic obliquity and trunk flexion was conducted using MANOVA. Kinematic and kinetic data were graphed with bootstrapped t-tests and 95% CI's normalised to the squat cycle. ANOVA and correlations in SPSS were used for exploratory analysis.

FINDINGS

On their symptomatic side cases squatted to less depth (-6.62°, p < 0.05) than controls with exploratory curve analysis revealing a pattern of increased knee valgus collapse throughout the squatting movement (p < 0.05). Greater patella tendon force was generated by: the eccentric than concentric phase of squatting (+30-43%, ES 0.52-1.32, p < 0.01), declined (plantarflexed) compared to horizontal surface (+36-51%, ES 1.19-1.68, p < 0.01) and deeper knee flexion angles (F ≥ 658.3, p < 0.01) with no difference between groups (F ≤ 1.380, p > 0.05). Cases experienced more pain on testing on decline board (ES = 0.69, p < 0.01). For symptomatic limbs pain (r_s = 0.458-0.641, p ≤ 0.05), but not VISA-P (Victoria Institute of Sport Assessment) (r_s = 0.053-0.090, p > 0.05), correlated with extensor knee moment.

INTERPRETATION

Knee valgus alignment is a plausible risk factor for patellar tendinopathy. Conclusions relating to causation are limited by the cross-sectional study design. Increasing squat depth, use of a declined surface and isolating the eccentric phase enable progression of loading prescription guided by pain.

Single leg squat ratings by clinicians are reliable and predict excessive hip internal rotation moment

BACKGROUND

Single leg squats are commonly used subjective assessments of general biomechanical function, injury risk, as a predictor for recovery and as an outcome measure of rehabilitation. While 3D motion capture is a useful tool for elite sports performance and research it is impractical for routine clinical use.

RESEARCH QUESTION

This cross-sectional study aims to: assess reliability and validity of clinicians' subjective ratings of single leg squats compared to 3D motion capture, and to identify whether performance predicts joint moments.

METHODS

22 healthy military volunteers were simultaneously recorded on video and 3D motion capture performing single leg squats. Videos were reviewed twice by 5 physiotherapists rating performance on a 0-5 scale assessing squat depth, hip adduction, pelvic obliquity, pelvic tilt and trunk flexion summated into a composite score.

RESULTS

Hip adduction and trunk flexion exhibited moderate to substantial inter- and intra-rater reliability (range κ = 0.408-0.699) other individual criteria were mostly fair (κ ≤ 0.4). Composite scores for inter-rater reliability were ICC_(1,1) = 0.419 and ICC_(1,κ) = 0.783 and intra-rater reliability were ICC_(1,1) = 0.672 and κ(w) = 0.526. Validity against 3D kinematics was poor with only 6/75 individually rated criteria reaching κ > 0.40. Correlation was found between composite scores and hip internal rotation moment (r_s = 0.571, p = 0.009).

SIGNIFICANCE

Repeated use of single leg squats by a single practitioner is supported. Comparisons between clinicians are unreliable but improved by average measures from multiple raters. Heterogeneous reliability across scoring components suggests a qualitative description of the criteria scored is less ambiguous than using composite scores in a clinical setting. Composite scores may be more useful for analysis at a population level. Poor validity against kinematic data suggests clinicians use additional information upon which they find agreement such as estimating kinetics. Correlation between hip internal rotation moment and subjective ratings may be such an example of clinicians trying to identify excessive abnormal loading.

Gender differences in knee abduction during weight-bearing activities: A systematic review and meta-analysis

BACKGROUND

Increased knee abduction during weight-bearing activities is suggested to be a contributing factor for the high knee injury risk reported in women. However, studies investigating gender difference in knee abduction are inconclusive.

OBJECTIVE

To systematically review gender-differences in knee abduction during weight-bearing activities in individuals with or without knee injury.

METHODS

A systematic review and meta-analysis were conducted according to the PRISMA guidelines. A search in the databases Medline, CINAHL and EMBASE was performed until September 2015. Inclusion criteria were studies that reported (1) gender differences, (2) healthy individuals and/or those with anterior cruciate ligament (ACL) deficiency or reconstruction or patellofemoral pain PFP, and (3) knee abduction assessed with either motion analysis or visual observation during weight-bearing activity.

RESULTS

Fifty-eight articles met the inclusion criteria. Women with PFP had greater peak knee abduction compared to men (Std diff in mean; -1.34, 95%CI; -1.83 to -0.84). In healthy individuals, women performed weight-bearing tasks with greater knee abduction throughout the movement (initial contact, peak abduction, excursion) (Std diff in mean; -0.68 to -0.79, 95%CI; -1.04 to -0.37). In subgroup analyses by task, differences in knee abduction between genders were present for most tasks, including running, jump landings and cutting movements. There were too few studies in individuals with ACL injury to perform meta-analysis.

CONCLUSION

The gender difference in knee abduction during weight-bearing activities should be considered in training programs aimed at preventing or treating knee injury.