Objectives: To investigate differences between hip abductor muscle strength, hip and knee adduction moments and knee joint alignment in people with moderate/severe and mild medial compartment knee osteoarthritis (OA), and people without OA, and identify variables explaining variance in knee adduction moment in participants with OA. Background: It has been suggested that weakness of hip abductor muscles may lead to displacement of the centre of mass of body away from the stance limb during gait, resulting in increased knee adduction moment, a predictor of disease progression. Methods: Participants with medial compartment knee OA were divided into moderate/severe (n=23) and mild OA groups (n=15) based on radiographic grading. Control subjects were recruited to match participants in the moderate/severe group for age and gender (n=23). Hip abductor and adductor muscle isometric strength was measured using the Biodex dynamometer. Gait speed and hip and knee peak adduction moments and percentage of the stance phase where these occurred were obtained using a three dimensional motion analysis system and two force platforms. Knee alignment and severity of OA were measured from radiographs. Statistics: Univariate analysis of variance (ANOVA) was performed to determine group differences. Stepwise linear regression analysis was performed to identify the variables which contribute to variation in knee adduction moment. Results: Moderate/severe OA group participants had higher body mass index (BMI) than the mild OA and control group (p=0.01) and greater varus alignment compared to the control group (p<0.01). There was no difference between the mean hip abductor and adductor muscle strength and hip and knee adduction moments among the three groups. Peak hip (p=0.02) and knee adduction moments (p<0.05) occurred later in stance phase of gait in the moderate/severe OA group as compared to control group. Knee joint alignment (26%), hip abductor muscle isometric strength (20%), gait speed (16%) and hip adduction moment (11%) explained 73% of variance in the knee adduction moment in the participants with OA. Conclusion: Findings from this study do not support the theory that weakness of the hip abductor muscles contributes to higher knee adduction moments. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2008-03-03 21:47:07.309

This thesis focused on the proximal factors associated with PFP, particularly, on hip muscle function. The overall purpose of this thesis was to elaborate a test, reliable and valid, for evaluating hip muscle function in females with PFP and that could be easily be used in the clinic. To reach this purpose, three sections have been considered:• Section 1 presented the results of a systematic review with meta-analysis entitled “Strength and endurance in females with patellofemoral pain”. This systematic review provided strong evidence that females with PFP have significant isometric strength deficit in hip abduction, extension, and external rotation when compared with healthy controls. Moderate evidence was obtained concerning isometric strength deficit in flexion. There was no evidence that females with PFP have strength deficits in adduction and internal rotation. Moderate evidence was found for isokinetic deficit in abduction and conflicting evidence for a deficit in rotation and extension. When compared with the uninjured limb, moderate evidence was found for a strength deficit in abduction, conflicting evidence for deficiencies in extension and external rotation strength and no evidence for internal rotation, adduction and flexion strength deficiencies. Finally, conflicting evidence was found for a decrease in hip muscular endurance.• Section 2 elaborated two clinical tests for the assessment of hip abductor endurance. After a preliminary phase, the hip abductor isometric endurance test was selected. The test-retest reliability and the validity were determined in healthy females and we concluded that the test could be recommended for clinicians.• Section 3 determined the applicability of the hip abductor isometric endurance test in females with PFP. We assessed the test-retest reliability of the hip abductor isometric endurance test in females with PFP and we compared holding time during the test between females with and without PFP. In this chapter, we chose also to use two others clinical tests, evaluating trunk extensor and ankle plantar flexor endurance, to compare females with and without PFP. We reported that females with PFP exhibited significantly lower hip abductor, trunk extensor and ankle plantar flexor endurance than healthy controls and we concluded that the hip abductor isometric endurance test could be recommended for the examination of patients with PFP. / Doctorat en Sciences de la motricité / info:eu-repo/semantics/nonPublished

The Gluteus Medius and the Tensor Fascia Lata are two of the main muscles involved in the action of hip abduction. This action is important for both dynamic movements in athletic pursuits and in every day ambulation. Weakness in these muscles has been connected to multiple injuries in the lower limb, but the question of the casual relationship between gait change, hip abductor weakness, and lower limb injury is still up for debate. As presented by the current research, younger populations tend to have overuse injuries with females having a greater susceptibility for injuries connected to hip abductor weakness, and older populations tend to have injures related to atrophy and degeneration of either the hip abductor muscles or the joint surrounding the hip. Research in this field has increasingly focused on sub-sets of the populations, such as just females or just males, trying to pinpoint the role that hip abductor weakness plays in these injuries. By trying to minimize or even eliminate the confounding variables that have previously made it difficult to determine the role hip abductor weakness plays in these gait changes and injuries, these studies have been able to make more clear conclusions at the expense of making a broader generalization. Similarities and differences between how the sub-groups present with hip abductor weakness are discussed, as well as discrepancies observed within the research done on similar cohorts. Future directions for research in this field are discussed, as well as implications for clinical implementation of targeted rehabilitation programs to ensure the best possible outcomes.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal