Hip strength does not correlate with hip and knee biomechanics during single-leg tasks: A systematic review with meta-analysis and evidence gap map

We systematically reviewed and synthesized the evidence for the relationship between hip strength and hip and knee biomechanics during single-leg tasks in uninjured and injured populations. We searched CINAHL, EMBASE, PubMed, SportDiscus, and Web of Science from inception to July 2024. We included cross-sectional studies with uninjured and/or injured participants that reported correlations between hip strength and hip or knee kinematics during a single-leg task. We identified 41 articles that reported the correlations between hip strength and hip or knee kinematics during a single-leg task for uninjured (n = 33) and/or injured (n = 12) populations. We identified moderate-to-strong evidence for no-to-poor relationships between most hip strength and hip and knee kinematics during a single-leg task for uninjured (r = -0.33-0.45) and injured populations (r = -0.24-0.24). We observed limited-to-moderate evidence for fair-to-moderate negative relationships between concentric and eccentric hip abduction strength and hip adduction (r = -0.52) and knee abduction kinematics (r = -0.45-0.59) for uninjured populations. Isometric hip strength may not play as important of a role in controlling lower extremity motion during single-leg tasks as previously perceived, but isokinetic strength may be a better indicator of lower extremity motion during single-leg tasks.Trial Registration:PROSPERO#CRD42020153166.

Objective Clinical Measurement Tools for Functional Evaluation of the Surgical Patient

Following knee surgery, clinicians have traditionally used visually rated or time-based assessments of lower extremity movement quality to measure surgical outcomes, plan rehabilitation interventions, and measure success. These methods of assessment are prone to error and do not fully capture a patient's inefficient movement patterns post surgery. Further, currently available systems which objectively measure kinematics during these tasks are expensive and unidimensional. For these reasons, recent research has called for the development of objective and low-cost precision rehabilitation tools to improve clinical measurement of movement tasks. The purpose of this article is to highlight two such tools and their applications to knee surgery. The systems highlighted within this article are the Mizzou Point-of-Care Assessment System (MPASS) and the Mizzou Knee Arthrometer Testing System (MKATS). MPASS has demonstrated high levels of agreement with the gold-standard Vicon system in measuring kinematics during sit-to-stand (R > 0.71), lateral step-down (intraclass correlation coefficient [ICC] > 0.55, apart from ankle flexion), and drop vertical jump tasks (ICC > 0.62), as well as gait (R > 0.87). MKATS has been used to quantify differences in tibiofemoral motion between groups during lateral step-down, step-up-and-over, and step-up/step-down tasks. Objective measurement of clinical tasks using portable and inexpensive instruments, such as the MPASS and MKATS, can help clinicians identify inefficient movement patterns and asymmetries which may damage and wear down supporting structures within the knee and throughout the kinetic chain causing pain and discomfort. Identifying these issues can help clinicians to plan interventions and measure their progress at a lower cost than currently available systems. The MPASS and MKATS are useful tools which have many applications to knee surgery.

Serial Subtraction Alters Lateral Step-down Tibiofemoral Kinematics in Healthy Adults

This study evaluated the effects of two types of cognitive dual-tasking on three-dimensional knee kinematics during the lateral step-down. 19 healthy individuals (22.05±1.61 yrs., 173.92±9.21 cm, 67.99±12.65 kg) participated in this study. Participants completed 5 repetitions of a lateral step-down task for each leg and each testing condition (control, Stroop, and serial subtraction by seven). An electromagnetic motion sensor was attached to the femur via compression clamp placed about the medial and lateral epicondyles. Another sensor was attached 2 cm below the ipsilateral tibial tuberosity. A custom MATLAB algorithm located the knee joint axis of rotation from dynamic knee flexion and extension. Discrete kinematics at peak flexion were used in this study. Paired samples t-tests were used to compare average frontal, transverse, and sagittal plane knee position at maximum flexion between conditions for each leg. No significant differences were found for either limb between control and Stroop conditions. Comparisons revealed significant differences in frontal and transverse plane knee angles at peak flexion between the control and serial subtraction by seven conditions. These findings indicate serial subtraction by seven requires different cognitive processing abilities which may cause greater interference with some aspects of motor control.

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.

Reliability of two functional clinical tests to evaluate trunk and lumbopelvic neuromuscular control and proprioception in a healthy population

OBJECTIVES

The need to accurately assess trunk and lumbopelvic proprioception and neuromuscular control is widely accepted. However, based on current literature, there is a lack of reliable clinical tests to evaluate these aspects in clinical practice. The objective of this study is to investigate intra- and inter-tester reliability of the lateral step down test and the lumbopelvic position-reposition test in a healthy population.

METHODS

Protocol and scoring methods were developed for the lateral step down test and lumbopelvic position-reposition test, used to assess trunk and lumbopelvic neuromuscular control and proprioception respectively. Each test was performed once by thirty participants and video analysis for test scoring was performed. Three items on the lateral step down test were scored to evaluate neuromuscular control and, four items on the lumbopelvic position-reposition test were scored to evaluate proprioception. Aggregate scores for each test were calculated based on the separate item scores. Intraclass correlation coefficients and linear weighted kappa coefficients were determined for intra- and inter-tester reliability.

RESULTS

Based on the aggregate score, excellent intra- and inter-tester reliability (ICC (2,1)=0.73-0.88) was found for both tests. Moderate/almost perfect intra-and inter-tester agreement (K=0.62-0.91) was found for the separate items of the lateral step down test and fair/substantial agreement (K=0.25-0.76) for the items of the lumbopelvic position-reposition test.

CONCLUSION

Current testing protocol and scoring method for the lateral step down test is reliable. Adjustments for the scoring method of the lumbopelvic position-reposition test are warranted to improve reliability.

Modifiable Factors Associated with Knee Abduction During Weight-Bearing Activities: A Systematic Review and Meta-Analysis

BACKGROUND

Increased knee abduction angle during activity is suggested to be a risk factor for sustaining an anterior cruciate ligament (ACL) injury or developing patellofemoral pain syndrome (PFPS). Knowledge of the modifiable mechanisms that are associated with increased knee abduction will aid in the appropriate design of preventive and rehabilitative strategies for these injuries.

OBJECTIVE

Our objective was to systematically review modifiable mechanisms contributing to increased knee abduction in healthy people and in individuals with an ACL injury or PFPS.

METHODS

We performed a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the databases MEDLINE, CINAHL, and Embase until September 2015. Inclusion criteria were studies in healthy individuals and/or those with ACL injury or PFPS reporting (1) muscle strength, muscle activation, proprioception, and/or range of motion (ROM) and (2) knee abduction angle assessed with either motion analysis or visual observation during weight-bearing activity.

RESULTS

In total, 33 articles were included. Reduced trunk strength, reduced gluteus maximus amplitude, decreased ankle ROM, and increased hip external rotation ROM were moderately associated with increased knee abduction angle (r -0.34 or higher, standardized difference in means (SDM) greater than -0.39, p < 0.05, articles n = 3, total sample size n = 101-114) in healthy individuals. Decreased strength of hip abductors, external rotators, and extensors and knee flexors were at most weakly associated with increased knee abduction angle (r ≤ 0.21, p = 0.013-0.426, articles n = 2-9, total sample size n = 80-311). Too few articles included patients with knee injury to be included in any meta-analysis.

CONCLUSION

The associations identified in this review indicate that investigation of strengthening of the trunk muscles, and improvement of gluteus maximus activation and ankle ROM to change knee kinematics is merited. Studies on modifiable factors associated with increased knee abduction angle in people with knee injury are needed.

The association of visually-assessed quality of movement during jump-landing with ankle dorsiflexion range-of-motion and hip abductor muscle strength among healthy female athletes

OBJECTIVE

To explore the association between ankle dorsiflexion (DF) range of motion (ROM), and hip abductor muscle strength, to visually-assessed quality of movement during jump-landing.

DESIGN

Cross-sectional.

SETTING

Gymnasium of participating teams.

PARTICIPANTS

37 female volleyball players.

MAIN OUTCOME MEASURES

Quality of movement in the frontal-plane, sagittal-plane, and overall (both planes) was visually rated as "good/moderate" or "poor". Weight-bearing Ankle DF ROM and hip abductor muscle strength were compared between participants with differing quality of movement.

RESULTS

Weight-bearing DF ROM on both sides was decreased among participants with "poor" sagittal-plane quality of movement (dominant side: 50.8° versus 43.6°, P = .02; non-dominant side: 54.6° versus 45.9°, P = .01), as well as among participants with an overall "poor" quality of movement (dominant side: 51.8° versus 44.0°, P < .01; non-dominant side: 56.5° versus 45.1°, P < .01). Weight-bearing ankle DF on the non-dominant side was decreased among participants with a "poor" frontal-plane quality of movement (53.9° versus 46.0°, P = .02). No differences in hip abductor muscle strength were noted between participants with differing quality of movement.

CONCLUSIONS

Visual assessment of jump-landing can detect differences in quality of movement that are associated with ankle DF ROM. Clinicians observing a poor quality of movement may wish to assess ankle DF ROM.

Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut

Background:

The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD).

Hypothesis:

Females with greater hip abduction and extension RTD would exhibit lesser frontal plane hip and knee motion during a single-leg jump-cutting task.

Study Design:

Descriptive laboratory study.

Methods:

Forty recreationally active females performed maximal isometric contractions and single-leg jump-cuts. From recorded torque data, hip extension and abduction RTD was calculated from torque onset to 200 ms after onset. Three-dimensional motion analysis was used to quantify frontal plane hip and knee kinematics during the movement task. For each RTD measure, jump-cut biomechanics were compared between participants in the highest (high) and lowest (low) RTD tertiles.

Results:

No differences in frontal plane hip and knee kinematics were identified between high and low hip abduction RTD groups. However, those in the high hip extension RTD group exhibited lower hip adduction (high, 3.8° ± 3.0°; low, 6.5° ± 3.0°; P = .019) and knee valgus (high, –2.5° ± 2.3°; low, –4.4° ± 3.2°; P = .046) displacements during the jump-cut.

Conclusion:

In movements such as cutting that are performed with the hip in a relatively abducted and flexed position, the ability of the gluteus medius to control hip adduction may be compromised. However, the gluteus maximus, functioning as a hip abductor, may take on a pivotal role in controlling hip adduction and knee valgus motion during these types of tasks.

Clinical Relevance:

Training with a specific emphasis on increasing explosive strength of the hip extensors may be a means through which to improve frontal plane hip and knee control during high-risk maneuvers such as cutting.

Repeatability of a 3D multi-segment foot model during anterior and lateral step down tests

The aim of the present study was to analyse the reproducibility of the Oxford Foot Model (OFM) when used with healthy adults during two clinical tests, i.e., the Anterior Step Down Test (SDA) and the Lateral Step Down Test (SDL). Five healthy participants (one male and four females, 10 limbs in total) with a mean age of 22.2 (19-30) years were assessed in four sessions of tests conducted at intervals of one week. Two independent examiners performed two of the sessions of each of the tests. For each session (intra-day), nine repetitions of each clinical test (SDA and SDL) were performed. After an interval of three hours, the data were collected again. The tests were conducted again after an interval of one week using the same experimental conditions. The intra- and inter-session repeatabilities of the ranges of motion of the feet were determined according to the standard error of measurement (SEM) for each examiner and for the differences between the examiners. The repeatabilities of the results were high for both of the conducted tests. The SEM results were as follows: 0.47-1.94° for the intra-examiner assessment (SDA), 0.55-2.01° for the inter-examiner comparison (SDA), 0.44-2.43° for the intra-examiner assessment (SDL), and 0.54-1.89° for the inter-examiner comparison (SDL). The OFM model was shown to be reproducible in terms of assessing the range of motion of healthy adults during functional tests (SDA and SDL).

Factors associated with visually assessed quality of movement during a lateral step-down test among individuals with patellofemoral pain

STUDY DESIGN

Cross-sectional.

OBJECTIVE

To determine what physical measures are associated with visually assessed quality of movement among patients with patellofemoral pain (PFP).

BACKGROUND

An altered movement pattern has been implicated as a risk factor for PFP. An understanding of physical measures associated with an altered movement pattern could potentially help guide prevention and management efforts in patients with PFP.

METHODS

Seventy-nine (40 women) Israel Defense Forces soldiers referred to physical therapy with a diagnosis of PFP were included. Movement pattern was assessed visually during a lateral step-down test and rated as "good" or "moderate," based on previously established criteria. Weight-bearing and non-weight-bearing ankle dorsiflexion (DF) range of motion (ROM); hip internal and external rotation ROM; and hip abduction, hip external rotation, and knee extension strength were also assessed. Differences in physical measures between those with good versus moderate quality of movement were assessed.

RESULTS

Weight-bearing DF ROM was more limited among participants with a moderate quality of movement compared to those with a good quality of movement (P<.01). Among men, non-weight-bearing DF ROM was more limited in those with a moderate quality of movement as well (P<.01). In addition, quality of movement was associated with weight-bearing DF ROM for both women (r = -0.39, P = .01) and men (r = -0.46, P<.01), and with non-weight-bearing DF ROM for men (r = -0.66, P<.01). When the subgroup of participants who exhibited more than 25° of non-weight-bearing DF ROM was assessed, those with a good quality of movement displayed greater hip external rotator and knee extensor muscle strength compared with those with a moderate quality of movement (P<.01).

CONCLUSION

Ankle DF ROM should be assessed when patients with PFP demonstrate a lower quality of movement during a lateral step-down test. Lower hip muscle strength may be associated with lower quality of movement among patients with relatively greater ankle DF ROM.

Two- and 3-dimensional knee valgus are reduced after an exercise intervention in young adults with demonstrable valgus during squatting

CONTEXT

Two-dimensional (or medial knee displacement [MKD]) and 3-dimensional (3D) knee valgus are theorized to contribute to anterior cruciate ligament injuries. However, whether these displacements can be improved in the double-legged squat (DLS) after an exercise intervention is unclear.

OBJECTIVE

To determine if MKD and 3D knee valgus are improved in a DLS after an exercise intervention.

DESIGN

Randomized controlled clinical trial.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 32 participants were enrolled in this study and were randomly assigned to the control (n = 16) or intervention (n = 16) group. During a DLS, all participants demonstrated knee valgus that was corrected with a heel lift.

INTERVENTION(S)

The intervention group completed 10 sessions of directed exercise that focused on hip and ankle strength and flexibility over a 2- to 3-week period.

MAIN OUTCOME MEASURE(S)

We assessed MKD and 3D knee valgus during the DLS using an electromagnetic tracking system. Hip strength and ankle-dorsiflexion range of motion were measured. Change scores were calculated for MKD and 3D valgus at 0%, 10%, 20%, 30%, 40%, and 50% phases, and group (2 levels)-by phase (6 levels) repeated-measures analyses of variance were conducted. Independent t tests were used to compare change scores in other variables (α < .05).

RESULTS

The MKD decreased from 20% to 50% of the DLS (P = .02) and 3D knee valgus improved from 30% to 50% of the squat phase (P = .001). Ankle-dorsiflexion range of motion (knee extended) increased in the intervention group (P = .009). No other significant findings were observed (P > .05).

CONCLUSIONS

The intervention reduced MKD and 3D knee valgus during a DLS. The intervention also increased ankle range of motion. Our inclusion criteria might have limited our ability to observe changes in hip strength.