Changes in foot progression angle during gait reduce the knee adduction moment and do not increase hip moments in individuals with knee osteoarthritis

People with knee osteoarthritis who adopt a modified foot progression angle (FPA) during gait often benefit from a reduction in the knee adduction moment and knee pain. It is unknown, however, whether changes in the FPA increase hip moments, a surrogate measure of hip loading, which may increase the risk of hip pain or osteoarthritis. This study examined how altering the FPA affects hip moments. Individuals with knee osteoarthritis walked on an instrumented treadmill with their baseline gait, 10° toe-in gait, and 10° toe-out gait. A musculoskeletal modeling package was used to compute joint moments from the experimental data. Fifty participants were selected from a larger study who reduced their peak knee adduction moment with a modified FPA. In this group, participants reduced the first peak of the knee adduction moment by 7.6% with 10° toe-in gait and reduced the second peak by 11.0% with 10 ° toe-out gait. Modifying the FPA reduced the early-stance hip abduction moment, at the time of peak hip contact force, by 4.3% ± 1.3% for 10° toe-in gait (p=0.005) and by 4.6% ± 1.1% for 10° toe-out gait (p<0.001) without increasing the flexion and internal rotation moments (p>0.15). In summary, when adopting a FPA modification that reduced the knee adduction moment, participants did not increase surrogate measures of hip loading.

Reliability of hip joint position sense tests using a clinically applicable measurement tool in elderly participants with unilateral hip osteoarthritis

Hip joint proprioception is vital in maintaining posture and stability in elderly individuals. Examining hip joint position sense (JPS) using reliable tools is important in contemporary clinical practice. The objective of this study is to evaluate the intra-rater and inter-rater reliability of hip JPS tests using a clinically applicable measurement tool in elderly individuals with unilateral hip osteoarthritis (OA). Sixty-two individuals (mean age = 67.5 years) diagnosed with unilateral hip OA participated in this study. The JPS tests were evaluated using a digital inclinometer in hip flexion and abduction directions. The absolute difference between target and reproduced angle (repositioning error) in degrees was taken to measure JPS accuracy. The intraclass correlation coefficient (ICC (2.k), was used to assess the reliability. The Intra rater-reliability for hip JPS tests showed very good agreement in the lying position (hip flexion-ICC = 0.88–0.92; standard error of measurement (SEM) = 0.06–0.07, hip abduction-ICC = 0.89–0.91; SEM = 0.06–0.07) and good agreement in the standing position (hip flexion-ICC = 0.69–0.72; SEM = 0.07, hip abduction-ICC = 0.66–0.69; SEM = 0.06–0.08). Likewise, inter-rater reliability for hip JPS tests demonstrated very good agreement in the lying position (hip flexion-ICC = 0.87–0.89; SEM = 0.06–0.07, hip abduction-ICC = 0.87–0.91; SEM = 0.07) and good agreement in the standing position (hip flexion-ICC = 0.64–0.66; SEM = 0.08, hip abduction-ICC = 0.60–0.72; SEM = 0.06–0.09). The results support the use of hip JPS tests in clinical practice and should be incorporated in assessing and managing elderly participants with hip OA.

Efficacy of Exercise-Based Rehabilitation Programs for Improving Muscle Function and Size in People with Hip Osteoarthritis: A Systematic Review with Meta-Analysis

Objective: To determine the effect of exercise-based rehabilitation programs on hip and knee muscle function and size in people with hip osteoarthritis. Methods: Seven databases were systematically searched in order to identify studies that assessed muscle function (strength or power) and size in people with hip osteoarthritis after exercise-based rehabilitation programs. Studies were screened for eligibility and assessed for quality of evidence using the GRADE approach. Data were pooled, and meta-analyses was completed on 7 of the 11 included studies. Results: Six studies reported hip and/or knee function outcomes, and two reported muscle volumes that could be included in meta-analyses. Meta-analyses were conducted for four strength measures (hip abduction, hip extension, hip flexion, and knee extension) and muscle size (quadriceps femoris volume). For hip abduction, there was a low certainty of evidence with a small important effect (effect size = 0.28, 95% CI = 0.01, 0.54) favouring high-intensity resistance interventions compared to control. There were no other comparisons or overall meta-analyses that identified benefits for hip or knee muscle function or size. Conclusion: High-intensity resistance programs may increase hip abduction strength slightly when compared with a control group. No differences were identified in muscle function or size when comparing a high versus a low intensity group. It is unclear whether strength improvements identified in this review are associated with hypertrophy or other neuromuscular factors.

Lower Extremity Flexibility Profile in Basketball Players: Gender Differences and Injury Risk Identification

Analysis of the flexibility profile of basketball players (BPs) can reveal differences in range of motion (ROM) by gender and also identify those players who are at higher risk for sports injuries. A descriptive observational study was conducted to determine the lower extremity flexibility profile of sixty-four basketball players and gender differences to identify players at higher risk of injury due to limited and asymmetric ROM in one or more movements. Participants: Sixty-four (33 male and 31 female) competitive athletes from the national leagues of the Spanish basketball league system participated in the present study (power of sample size ≥0.99). The eight passive ROM tests of the hip, knee and ankle were assessed using the ROM-SPORT battery. Each player completed a questionnaire on age, basic anthropometric data, dominant extremities, and training and sport-related variables. The lower extremity flexibility profile was established at 15° and 10° hip extension (HE), 39° and 38° ankle dorsiflexion with knee extended (ADF-KE), 40° and 39° ankle dorsiflexion with knee flexed (ADF-KF), 43° and 43° hip abduction (HAB), 75° and 61° hip abduction with the hip flexed (HAB-HF), 78° and 83° hip flexion with the knee extended (HF-KE), 134° and 120° knee flexion (KF), and 145° and 144° hip flexion (HF) by male and female basketball players, respectively. Sex differences in HE, HAB-HF, and KF were observed in BPs (p ≤ 0.01; Hedges’ g ≥ 1.04). Players reported limited ROM in ADF-KF, HE, HAB-HF, HF-KE, and KF; and asymmetric ROM mainly in HE, ADF-KE, KF, ADF-KF, and HF-KE. In conclusion, this study provides gender-specific lower extremity flexibility profile scores in BPs that can help athletic trainers and athletic and conditioning trainers to identify those players who are at higher risk of injury due to abnormal ROM scores.

Effect of side-sling plank exercise on trunk and hip muscle activation in subjects with gluteus medius weakness

BACKGROUND: The effectiveness of side-sling plank (SSP) exercises on trunk and hip muscle activation in subjects with gluteus medius (Gmed) weakness is unclear. OBJECTIVE: To quantify muscle activation of the rectus abdominis (RA), external oblique (EO), erector spinae (ES), lumbar multifidus (LM), Gmed, gluteus maximus (Gmax), and tensor fasciae latae (TFL) during SSP with three different hip rotations compared to side-lying hip abduction (SHA) exercise in subjects with Gmed weakness. METHODS: Twenty-two subjects with Gmed weakness were recruited. SHA and three types of SSP exercises were performed: SSP with neutral hip (SSP-N), hip lateral rotation (SSP-L), and hip medial rotation (SSP-M). Surface electromyography was used to measure the activation of the trunk and hip muscles. RESULTS: The trunk and hip muscles activations were generally significantly higher level during three SSP than SHA. SSP-M showed significantly lower EO activation while significantly higher ES and LM activation than SSP-L. Gmed activation was significantly higher during SSP-M than during SSP-L. TFL activation was significantly lower during SSP-M than during SSP-N and SSP-L. CONCLUSIONS: SSP could be prescribed for patients who have reduced Gmed strength after injuries. Especially, SSP-M could be applied for patients who have Gmed weakness with dominant TFL.

The prevention of injuries among youth basketballers according to the “Sequence of Prevention’’: a systematic review

Background: Basketball is played by the youth worldwide, and various injuries occur in youth basketball. There is currently no overview of the incidence, the risk factors and preventive measures of musculoskeletal injuries among youth basketball players. Objective: This systematic review describes the most common injuries among youth basketball players. The most common risk factors and various preventive measures and interventions have also been reported and discussed. Methods: Search strategies were built based on groups of keywords, namely ‘injury’, ‘youth basketball’, and ‘cohort’. Search strategies were entered into Medline and SPORTDiscus. Titles, abstracts and full text articles were screened by two researchers. Data from the included articles were extracted by one researcher and checked by another researcher. Results: Twenty-seven studies showed that the overall injury rate ranged from 2.64 to 3.83 per 1 000 hours of exposure. Ankle- (22%-37%) and knee injuries (5%-41%) were the most common injuries. Risk factors for knee injuries included ankle dorsiflexion with a range less than 36.5 degrees and female athletes with greater hip abduction strength. High variations of postural sway corresponded to occurrences of ankle injuries (p=0.01, OR =1.22; p<0.001, OR =1.22). A core intervention (rate = 4.99/1 000 athlete exposure (AEs)) focused on the trunk and lower extremity led to a reduction in injuries compared to a sham intervention (rate =7.72/1 000 AEs) (p=0.02). Wearing a McDavid Ultralight 195 brace reduced ankle injuries compared to the controls (HR 0.30; 95 % CI 0.17 0.90; p=0.03). Conclusion: Ankle and knee injuries are the most common injuries among youth basketball players. Poor postural control, reduced ankle dorsiflexion and high hip abduction strength are the main risk factors. A neuromuscular warm-up, in combination with strength and stability exercises, seems to be the best training method to prevent injuries. Ankle injuries can be reduced by wearing a lace-up ankle brace.

Effects of task and hip-abductor fatigue on lower limb alignment and muscle activation

Purpose Fatigue-induced hip-abductor weakness may exacerbate lower-limb misalignments during different dynamic single-leg tasks. We sought to evaluate the effects of fatigue and task on lower limb kinematics and muscle activation and to find associations between measurements obtained in two tasks. Methods One-group pretest–posttest design. Seventeen healthy adults (9 W) performed the single-leg squat (SLSQUAT) and the single-leg hop (SLHOP) before and after a hip-abduction fatigue protocol. Hip adduction, knee frontal plane projection angle (knee FPPA) and heel inversion displacement were measured during the eccentric phase of the SLSQUAT and the SLHOP, as well as activation of the gluteus medius (GMed), tensor fascia latae (TFL), peroneus longus (PER) and tibialis anterior (TA). Moments and tasks were compared using a repeated-measures two-way ANOVA. Correlation between tasks was evaluated using Spearman’s correlation. Results No differences in kinematics or activation were found between moments. Hip-adduction displacement (P = 0.005), GMed (P = 0.008) and PER (P = 0.037) activation were higher during SLSQUAT, while TA activation was higher during SLHOP (P < 0.001). No differences were found between tasks in knee FPPA and heel inversion. Hip-adduction and knee FPPA were not correlated between tasks, while ankle inversion displacement was positively correlated (rs = 0.524–0.746). Conclusion Different characteristics of SLSQUAT (slower and deeper) seem to have led to increased hip adduction displacement, GMed, and PER activation and decreased TA activation, likely due to higher balance requirements. However, hip-abductor fatigue didn’t influence lower-limb alignment during the tasks. Finally, evaluations should be performed with different single-leg tasks since they don’t give the same lower-limb alignment information.

Hip Abductor and Adductor Rate of Torque Development and Muscle Activation, but Not Muscle Size, Are Associated With Functional Performance

Understanding the physiological variables that contribute to a functional task provides important information for trainers and clinicians to improve functional performance. The hip abductors and adductors muscles appear to be important in determining the performance of some functional tasks; however, little is known about the relationship of the hip abductor/adductors muscle strength, activation, and size with functional performance. This study aimed to investigate the relationship of maximum torque, rate of torque development (RTD), rate of activation (RoA), and muscle thickness of the hip abductors [tensor fascia latae (TFL) and gluteus medius (GM)] and adductor magnus muscle with the Four Square Step Test (FSST) and the two-leg hop test in healthy young adults. Twenty participants (five males) attended one testing session that involved ultrasound image acquisition, maximal isometric voluntary contractions (hip abduction and hip adduction) while surface electromyography (EMG) was recorded, and two functional tests (FSST and two-leg side hop test). Bivariate correlations were performed between maximum voluntary torque (MVT), RTD at 50, 100, 200, and 300ms, RoA at 0–50, 0–100, 0–200, and 0–300, and muscle thickness with the dynamic stability tests. For the hip abduction, MVT (r=−0.455, p=0.044) and RTD300 (r=−0.494, p=0.027) was correlated with the FSST. GM RoA50 (r=−0.481, p=0.032) and RoA100 (r=−0.459, p=0.042) were significantly correlated with the two-leg side hop test. For the hip adduction, there was a significant correlation between the FSST and RTD300 (r=−0.500, p=0.025), while the two-leg side hop test was correlated with RTD200 (r=0.446, p=0.049) and RTD300 (r=0.594, p=0.006). Overall, the ability of the hip abductor and adductor muscles to produce torque quickly, GM rapid activation, and hip abductor MVT is important for better performance on the FSST and two-leg hop tests. However, muscle size appears not to influence the same tests.