Changes in Knee and Trunk Alignment in People With Hip Pain and Healthy Controls When Using a Decline Board During Single-Leg Squat.

CONTEXT: Hip pain is associated with reduced hip muscle strength, range of movement (ROM), and decreased postural stability. Single-leg squat is a reliable and valid method to measure dynamic balance. OBJECTIVE: To evaluate the influence of physical characteristics and use of a decline board on squat performance in a hip pain population. DESIGN: Cross-sectional study setting. Clinical Patients: In total, 33 individuals scheduled for arthroscopic hip surgery were matched with 33 healthy controls. INTERVENTIONS: Hip and ankle ROM, hip strength, and trunk endurance were assessed, along with knee and trunk kinematics during squat on flat and 25° decline surfaces. MAIN OUTCOME MEASURES: Between-group and surface differences in alignment, between-group strength and ROM, and associations between alignment and physical characteristics were assessed and determined using mixed model analysis of variance and Pearson R. RESULTS: The hip pain group had significantly less strength and ROM for all directions except abduction strength and ankle dorsiflexion (P > .02). No differences existed between the 2 groups for trunk (P < .70) or knee displacement (P < .46) during squat on either surface. When the 2 groups were combined (n = 66), decline squat significantly reduced knee medial displacement in both limbs by approximately 1 cm (P < .01). Decline squat reduced trunk lateral movement on 1 side only (P = .03). Reduced knee displacement during decline squat showed fair association with less hip-extension strength (r = -.29), hip-flexion strength (r = -.25), and less dorsiflexion (r = -.24). Strength and range were not associated with trunk displacement. CONCLUSIONS: Decline squat reduced medial knee and lateral trunk displacement regardless of hip pain. Reductions may be greater in those with lesser hip muscle strength and dorsiflexion. Use of a decline board during squat for improving knee and trunk alignment should be considered as a goal of exercise intervention.

Associations between type and severity of hip pathology with pre-operative patient reported outcome measures.

BACKGROUND: The relationship between hip pathology and patient reported outcome responses following hip surgery has been previously investigated. No studies have investigated the relationship between pathology and patient reported outcome responses prior to surgery. OBJECTIVES: (1) Determine the prevalence of chondral and labral pathology identified during hip arthroscopy. (2) Determine the association between intra-articular findings and patient reported outcome scores in a pre-arthroscopy hip pain population. METHODS: Sixty-seven (22 female) participants scheduled for hip arthroscopy after clinical examination and radiographic assessment completed a series of patient reported outcomes (Hip Disability and Osteoarthritis Outcome Score; International Hip Outcome Tool; Pain on Activity; Visual Analogue Scale). Pathology discovered/addressed during arthroscopy was classified. Univariable and multivariable linear regression models were used to assess the relationship between demographics, pathology and patient reported outcome responses. RESULTS: Ninety-one percent of participants had labral pathology; 76% had acetabular chondropathy and 31% had femoral head chondropathy. Across the ten patient reported outcome subscales, severe femoral head chondropathy and large labral tears had the greatest number of significant associations with patient reported outcome scores. The strongest association was with 'Hip Disability and Osteoarthritis Outcome Score symptoms and stiffness' subscale, where severe femoral head chondropathy explained 22% of variability in symptoms and stiffness, when adjusted for Body Mass Index and presence of pincer morphology (p=0.002). CONCLUSION: Severe femoral head chondropathy and large labral tears along with a high prevalence of labral pathology and acetabular chondropathy were relatively common findings during hip arthroscopy. Severe femoral head chondropathy and large labral tears are most associated with patient reported outcome's, however, at best only explain 22% of the variability.

Greater understanding of normal hip physical function may guide clinicians in providing targeted rehabilitation programmes.

OBJECTIVES: This study investigated tests of hip muscle strength and functional performance. The specific objectives were to: (i) establish intra- and inter-rater reliability; (ii) compare differences between dominant and non-dominant limbs; (iii) compare agonist and antagonist muscle strength ratios; (iv) compare differences between genders; and (v) examine relationships between hip muscle strength, baseline measures and functional performance. DESIGN: Reliability study and cross-sectional analysis of hip strength and functional performance. METHODS: In healthy adults aged 18-50years, normalised hip muscle peak torque and functional performance were evaluated to: (i) establish intra-rater and inter-rater reliability; (ii) analyse differences between limbs, between antagonistic muscle groups and genders; and (iii) associations between strength and functional performance. RESULTS: Excellent reliability (intra-rater ICC=0.77-0.96; inter-rater ICC=0.82-0.95) was observed. No difference existed between dominant and non-dominant limbs. Differences in strength existed between antagonistic pairs of muscles: hip abduction was greater than adduction (p<0.001) and hip ER was greater than IR (p<0.001). Men had greater ER strength (p=0.006) and hop for distance (p<0.001) than women. Strong associations were observed between measures of hip muscle strength (except hip flexion) and age, height, and functional performance. CONCLUSIONS: Deficits in hip muscle strength or functional performance may influence hip pain. In order to provide targeted rehabilitation programmes to address patient-specific impairments, and determine when individuals are ready to return to physical activity, clinicians are increasingly utilising tests of hip strength and functional performance. This study provides a battery of reliable, clinically applicable tests which can be used for these purposes.