Kim Allison

Hip abductor muscle weakness in individuals with gluteal tendinopathy

PURPOSE This study aimed to compare hip abductor muscle strength between individuals with symptomatic, unilateral gluteal tendinopathy (GT), and asymptomatic controls. METHODS Fifty individuals with GT age between 35 and 70 yr and 50 sex- and age-comparable controls were recruited from the community. Maximal isometric strength (torque normalized to body mass) of the hip abductors was recorded in the supine position using an instrumented manual muscle tester. A two-way mixed ANCOVA, with covariates of self-reported pain during testing and pain limiting maximum effort, was used to compare hip abductor strength of the symptomatic and asymptomatic hip between GT and control individuals. Data were expressed as mean and SD, with the pairwise comparisons expressed as mean differences and 95% confidence intervals. RESULTS Individuals with GT demonstrated significantly lower hip abductor torque of both their symptomatic and asymptomatic hip than healthy controls (both P < 0.05), with mean strength deficits of 0.35 N·m·kg (32%) on the symptomatic hip and 0.25 N·m·kg (23%) on the asymptomatic hip. In individuals with GT, the symptomatic hip was significantly weaker than the asymptomatic hip with a mean strength deficit of 0.09 N·m·kg (11%) (P < 0.05). CONCLUSIONS People with unilateral GT demonstrate significant weakness of the hip abductor muscles bilaterally when compared with healthy controls. Although it is not clear whether hip weakness precedes GT or is a consequence of the condition, the findings provide a basis to consider hip abductor muscle weakness in the treatment plan for management of GT.

Kinematics and kinetics during walking in individuals with gluteal tendinopathy.

BACKGROUND Lateral hip pain during walking is a feature of gluteal tendinopathy but little is known how walking biomechanics differ in individuals with gluteal tendinopathy. This study aimed to compare walking kinematics and kinetics between individuals with and without gluteal tendinopathy. METHODS Three-dimensional walking-gait analysis was conducted on 40 individuals aged 35 to 70 years with unilateral gluteal tendinopathy and 40 pain-free controls. An analysis of covariance was used to compare kinematic and kinetic variables between groups. Linear regression was performed to investigate the relationship between kinematics and external hip adduction moment in the gluteal tendinopathy group. FINDINGS Individuals with gluteal tendinopathy demonstrated a greater hip adduction moment throughout stance than controls (standardized mean difference ranging from 0.60 (first peak moment) to 0.90 (second peak moment)). Contralateral trunk lean at the time of the first peak hip adduction moment was 1.2 degrees greater (P=0.04), and pelvic drop at the second peak hip adduction moment 1.4 degrees greater (P=0.04), in individuals with gluteal tendinopathy. Two opposite trunk and pelvic strategies were also identified within the gluteal tendinopathy group. Contralateral pelvic drop was significantly correlated with the first (R=0.35) and second peak (R=0.57) hip adduction moment, and hip adduction angle with the second peak hip adduction moment (R=-0.36) in those with gluteal tendinopathy. INTERPRETATION Individuals with gluteal tendinopathy exhibit greater hip adduction moments and alterations in trunk and pelvic kinematics during walking. Findings provide a basis to consider frontal plane pelvic control in the management of gluteal tendinopathy.

Longitudinal changes in knee kinematics and moments following knee arthroplasty: A systematic review

BACKGROUND Knee arthroplasty (KA) is recognized as an effective treatment of knee joint osteoarthritis and up to 90% of patients experience substantial pain relief. There has been no systematic review synthesizing the longitudinal changes in gait following KA. The aims of this systematic review were to determine the effects of KA on (i) frontal plane and (ii) sagittal plane kinematic and kinetic parameters during the stance phase of gait. METHODS MEDLINE (PubMed), CINAHL, SPORTdiscus (EBSCO), and Cochrane Library (Wiley) were searched until April 10th, 2014. 1,765 articles were identified, of which 19 studies describing 3-dimensional gait analysis pre- and post-KA were included. Study quality was evaluated by two reviewers independently using the Downs and Black checklist. FINDINGS Following KA, in the frontal plane, the maximum knee adduction angle and external knee adduction moment (KAM) tended to decrease. In the sagittal plane, findings suggest that the maximum knee flexion moment is increased. From the ten studies that included a healthy reference group, it was unclear whether gait variables returned to normal following KA. INTERPRETATION Overall, it appears that KA results in a decreased peak KAM and maximum knee adduction angles, an increased peak knee flexion moment and inconsistent changes in the peak knee flexion angle. Knowledge gaps remain due to methodological inconsistencies across studies, limited statistical analysis, and largely heterogeneous sample populations. More research is needed to determine whether KA restores gait patterns to normal, or if additional rehabilitation may be needed to optimize gait following surgery for osteoarthritis.

Single leg stance control in individuals with symptomatic gluteal tendinopathy

BACKGROUND Lateral hip pain during single leg loading, and hip abductor muscle weakness, are associated with gluteal tendinopathy, but it has not been shown how or whether kinematics in single leg stance differ in those with gluteal tendinopathy. PURPOSE To compare kinematics in preparation for, and during, single leg stance between individuals with and without gluteal tendinopathy, and the effect of hip abductor muscle strength on kinematics. METHODS Twenty individuals with gluteal tendinopathy and 20 age-matched pain-free controls underwent three-dimensional kinematic analysis of single leg stance and maximum isometric hip abductor strength testing. Maximum values of hip adduction, pelvic obliquity (contralateral pelvis rise/drop), lateral pelvic translation (ipsilateral/contralateral shift) and ipsilateral trunk lean during preparation for leg lift and average values in steady single leg stance, were compared between groups using an analysis of covariance, with and without anthropometric characteristics and strength as covariates. RESULTS Individuals with gluteal tendinopathy demonstrated greater hip adduction (standardized mean difference (SMD)=0.70, P=0.04) and ipsilateral pelvic shift (SMD=1.1, P=0.002) in preparation for leg lift, and greater hip adduction (SMD=1.2, P=0.002) and less contralateral pelvic rise (SMD=0.86, P=0.02) in steady single leg stance than controls. When including strength as a covariate, only between-group differences in lateral pelvic shift persisted (SMD=1.7, P=0.01). CONCLUSION Individuals with gluteal tendinopathy use different frontal plane kinematics of the hip and pelvis during single leg stance than pain-free controls. This finding is not influenced by pelvic dimension or the potentially modifiable factor of body mass index, but is by hip abductor muscle weakness.

Kinematics and kinetics during stair ascent in individuals with Gluteal Tendinopathy

BACKGROUND Individuals with gluteal tendinopathy commonly report lateral hip pain and disability during stair ascent. This study aimed to compare kinematics and kinetics between individuals with and without gluteal tendinopathy during a step up task. METHODS 35 individuals with unilateral gluteal tendinopathy and 35 pain-free controls underwent three-dimensional motion analysis of stance phase during stair ascent. An analysis of covariance was performed to compare hip, pelvis and trunk kinematic and kinetic variables between groups. A K-means cluster analysis was performed to identify subgroups from the entire group (n=70) based on the characteristics of the external hip adduction moment. Finally, a Newcombe-Wilson test was performed to evaluate the relationship between group and cluster codes and a 3×2 ANOVA to investigate the differences in kinematics between groups and cluster codes. FINDINGS Individuals with gluteal tendinopathy exhibited a greater hip adduction moment impulse during stair ascent (ES=0.83), greater internal rotation impulse during the first 50% stance phase (ES=0.63) and greater contralateral trunk lean throughout stance than controls (ranging from ES=0.67-0.93). Three subgroups based on hip adduction moment characteristics were identified. Individuals with GT were 4.5 times more likely to have a hip adduction moment characteristic of a large impulse and greater lateral pelvic translation at heel strike than the subgroup most likely to contain controls. INTERPRETATION Individuals with GT exhibit greater hip adduction moment impulse and alterations in trunk and pelvic kinematics during stair ascent. Findings provide a basis to consider frontal plane trunk and pelvic control in the management of gluteal tendinopathy.

Hip abductor muscle activity during walking in individuals with gluteal tendinopathy

The external hip adduction moment during walking is greater in individuals with gluteal tendinopathy (GT) than pain‐free controls. Although this likely represents a greater demand on the hip abductor muscles implicated in GT, no study has investigated activation of these muscles in GT. For this purpose, fine wire electrodes were inserted into the segments of the gluteus minimus and medius muscles, and surface electrodes placed on the tensor fascia lata, upper gluteus maximus, and vastus lateralis muscles of eight individuals with, and eight without, GT. Participants underwent six walking trials. Individual muscle patterns were compared between groups using a wavelet‐based linear effects model and muscle synergy analysis performed using non‐negative matrix factorization to evaluate muscle activation patterns, within‐ and between‐participant variability. Compared to controls, individuals with GT exhibited a more sustained initial burst of the posterior gluteus minimus and middle gluteus medius muscle segments. Two muscle synergies were identified; Synergy‐1 activated in early‐mid stance and Synergy‐2 in early stance. In GT participants, posterior gluteus minimus and posterior gluteus medius and tensor fascia lata contributed more to Synergy‐1 active during the period of single leg support. Participants with GT exhibited reduced within‐participant variability of posterior gluteus medius and reduced between‐participant variability of anterior gluteus minimus and medius and upper gluteus maximus. In conclusion, individuals with GT exhibit modified muscle activation patterns of the hip abductor muscles during walking, with potential relevance for gluteal tendon loading.

Frontal plane hip joint loading according to pain severity in people with hip osteoarthritis: HIP JOINT LOAD BY PAIN SEVERITY

The primary objective was to examine the hip adduction moment during walking in people with hip osteoarthritis (OA) according to pain severity. Sixty‐eight participants with unilateral symptomatic hip OA were included. Pain during walking was assessed on a 5‐point Likert item within the Western Ontario and McMaster Universities Index (no pain = 12; mild pain n = 37; moderate pain n = 19). Measures of the external hip adduction moment (peaks, Nm/BW × BH (%) and impulse, Nm.s/BW × BH (%)) were determined. Other measures included frontal plane hip, pelvis and trunk kinematics, walking speed and peak isometric hip abductor strength. Variables were compared according to pain severity using linear models and biomechanical variables were examined. Participants with moderate pain had a significantly higher second peak hip adduction moment and impulse compared to those with less pain. There was no difference in any measure of hip adduction moment between those with mild pain and no pain. There were no differences in kinematics across pain severity categories. Participants with moderate pain had a significantly slower walking speed compared to participants with mild and no pain. Participants with moderate pain had weaker peak isometric hip abductor strength compared to those with mild pain and no pain. The hip adduction moment during walking, hip abduction strength and walking speed differs according to pain severity during walking in people with hip OA.

Gluteal tendinopathy and hip osteoarthritis: different pathologies, different hip biomechanics

BACKGROUND Gluteal tendinopathy (GT) and hip osteoarthritis (OA) are the most common causes of hip pain and associated disability in older adults. Pain and altered walking biomechanics are common to both conditions. This study aimed to compare three-dimensional walking biomechanics between individuals with unilateral, symptomatic GT and HOA. METHODS Sixty individuals with symptomatic unilateral GT confirmed by magnetic-resonance-imaging and 73 individuals with symptomatic unilateral HOA (Kellgren-Lawrence Grade ≥ 2) underwent three-dimensional gait analysis. Maximum and minimum values of the external sagittal hip moment, the first peak, second peak and mid-stance minimum of the hip adduction moment (HAM), sagittal plane hip excursion and hip joint angles, pelvic obliquity and trunk lean, at the three HAM time points during stance phase of walking were compared between groups. RESULTS Compared to individuals with HOA, those with GT exhibited a greater hip peak extension moment (P < 0.001) and greater HAM throughout the stance phase of walking (P = 0.01-P < 0.001), greater hip adduction (P < 0.001) and internal rotation (P < 0.01-P < 0.001) angles and lower hip flexion angles and excursion (P = 0.02 - P < 0.001). Individuals with HOA exhibited a greater forward trunk lean (P ≤ 0.001) throughout stance, and greater ipsilateral trunk lean in the frontal plane (P < 0.001) than those with GT. CONCLUSION Despite presence of pain in both conditions, hip kinematics and kinetics differ between individuals with symptomatic unilateral GT and those with symptomatic unilateral HOA. These condition-specific impairments may be targets for optimization of management of HOA and GT.

Sex-specific walking kinematics and kinetics in individuals with unilateral, symptomatic hip osteoarthritis: A cross sectional study

BACKGROUND Hip osteoarthritis (OA) is a significant cause of disability, with hip pain and reduced external hip moments during walking being key features of the condition. The external hip adduction moment is greater in healthy women than men, however these between-sex differences are not evident in those with end-stage hip OA. Whether sex-specific hip kinetics are associated with early-midstage hip OA has not been investigated and may be a potential target for directed treatment. METHODS Thirty-eight women and twenty-eight men with a diagnosis of symptomatic, unilateral, mild-to-moderate hip OA (Kellegren-Lawrence Grade 2 or 3) underwent three-dimensional gait analysis of normal walking gait using Vicon motion capture. Hip joint, trunk and pelvic angles and hip moments were calculated using the Plug-in-Gait model. The external peak flexion moment, and the first peak, second peak and mid-stance minimum of the hip adduction moment during the stance phase of walking as well as hip, trunk and pelvic kinematics occurring at the three moment time points were compared between groups using an analysis of covariance. RESULTS Women with hip OA exhibited a greater external hip adduction moment (mean difference 0.8-1.3 N m/BW.Ht(%), P < 0.05) and greater hip adduction angles (mean difference 2.8-4.9 degrees, P < 0.05) throughout stance than men. Men walked with a greater forward trunk lean than women during early to midstance (mean difference 2.9-3.5 degrees, P < 0.05) than women. SIGNIFICANCE In contrastto late stage hip OA, between-sex difference in hip joint kinematics and kinetics are preserved in early-midstage hip OA.BACKGROUND Hip osteoarthritis (OA) is a significant cause of disability, with hip pain and reduced external hip moments during walking being key features of the condition. The external hip adduction moment is greater in healthy women than men, however these between-sex differences are not evident in those with end-stage hip OA. Whether sex-specific hip kinetics are associated with early-midstage hip OA has not been investigated and may be a potential target for directed treatment. METHODS Thirty-eight women and twenty-eight men with a diagnosis of symptomatic, unilateral, mild-to-moderate hip OA (Kellegren-Lawrence Grade 2 or 3) underwent three-dimensional gait analysis of normal walking gait using Vicon motion capture. Hip joint, trunk and pelvic angles and hip moments were calculated using the Plug-in-Gait model. The external peak flexion moment, and the first peak, second peak and mid-stance minimum of the hip adduction moment during the stance phase of walking as well as hip, trunk and pelvic kinematics occurring at the three moment time points were compared between groups using an analysis of covariance. RESULTS Women with hip OA exhibited a greater external hip adduction moment (mean difference 0.8-1.3 N m/BW.Ht(%), P < 0.05) and greater hip adduction angles (mean difference 2.8-4.9 degrees, P < 0.05) throughout stance than men. Men walked with a greater forward trunk lean than women during early to midstance (mean difference 2.9-3.5 degrees, P < 0.05) than women. SIGNIFICANCE In contrastto late stage hip OA, between-sex difference in hip joint kinematics and kinetics are preserved in early-midstage hip OA.

10 Hip Abductor Strength In Individuals With Gluteal Tendinopathy: A Cross-sectional Study

Introduction Gluteal tendinopathy (GT) is a prevalent, debilitating musculoskeletal disease characterised by lateral hip pain at or around the region of the greater trochanter. The condition involves tendinopathic change of the gluteus medius and/or gluteus minimus tendons [Lesquene 2008]. The gluteus medius and minimus muscles act as abductors of the hip. In GT, it is proposed that altered muscle activation patterns and excessive hip adduction in function can result in compression of the gluteal tendons against the greater trochanter, resulting in pathological tendon changes [Cook 2012]. Despite this widely held conviction and the derivation of conservative treatment programs based on this premise addressing hip abductor strength, there have been no studies to date investigating hip abductor strength in this population compared to controls. The aim of this study was to evaluate maximal isometric hip abductor strength in individuals with GT compared to healthy asymptomatic controls (AC). Methods A cross-sectional study: 23 individuals (5 males, 18 females) with unilateral MRI confirmed GT and 23 age- (within 2 years) and gender-matched AC’s were recruited. Control symptomatic’ and ‘asymptomatic’ hips were designated by matching sides (left or right) to that of their GT pair. Leg dominance (defined as the leg used to kick a ball) was noted. Isometric hip abduction strength was measured on both sides in supine (gravity-eliminated), in a position of ten degrees hip abduction. Measurement of maximal force was recorded in Newtons using a dynamometer placed above the lateral malleoli; the distance from the dynamometer to the greater trochanter (D) was recorded in metres. Three maximal attempts of a three second isometric abduction contraction were recorded, with a 60 second rest between efforts. The highest recorded value was used (with the value D) to calculate maximal isometric abduction torque, normalised to body mass (Nm/kg). Levels of lateral hip pain were self-reported using a numeric rating scale (0–10 with 10 being maximal pain) during strength testing, as well as day-to-day average pain, worst pain and duration of symptoms. Participants reported whether pain prevented them from pushing as hard as they could (pain inhibition). Data were analysed using a one-way ANOVA, and subsequently using an ANCOVA with covariates of pain levels, pain inhibition and leg dominance. Correlation analysis was performed using Spearman’s Rho to assess the relationship between abduction strength and duration of symptoms and average pain. Results The average duration of symptoms in the GT group was 31.2 (37.5) months. The GT group reported their day-to-day average lateral hip pain as 4.8 (0.8), worst pain experienced as 7.5 (1.3), and pain during testing as 3.0 (2.0). Eighteen of the 23 GT participants experienced pain during testing and 7 reported pain inhibition. When using pain inhibition, pain during testing and leg dominance as covariates, the GT group demonstrated significantly reduced hip abductor torque of both their symptomatic leg (p < 0.001) and of their asymptomatic leg (p = 0.024) when compared to the control group (Table 1). There was no significant correlation between symptomatic hip abductor strength and duration of symptoms (r =-0.32, p = 0.13) or symptomatic hip abductor strength and average pain (r = 0.13, p = 0.55). Abstract 10 Table 1 Maximal isometric hip abductor strength GTn = 23 ACn = 23 Mean Difference1 (CI 95%) p value2 Symptomatic Limb 0.82 (0.25) 1.12 (0.19) 0.30(0.17–0.44) 0.00 Asymptomatic Limb 0.90 (0.30) 1.09 (0.18) 0.19(0.04–0.33) 0.02 Values in Nm/kg reported Mean (Standard Deviation) 1 Asymptomatic Control minus Gluteal Tendinopathy 2 Adjusted for pain inhibition, pain during testing and leg dominance Discussion Individuals with GT demonstrated significantly reduced hip abductor strength bilaterally when compared to ACs. Patients in the GT group experienced only low levels of pain during isometric hip abduction, consistent with the rationale for isometric exercise prescription in tendinopathy. Electromyographic and biomechanical investigation in this population will provide further information regarding the potential relationship of hip abductor strength on functional hip adduction control and abductor muscle recruitment. References Lesquene et al. Arth Rheumatism 2008;59:241–246 Cook et al. Br J Sports Med 2012;46:163–168