Doctor of Philosophy
Health and Rehabilitation Sciences
Dr. Trevor Birmingham
Biomechanical factors during locomotion are important contributors to knee osteoarthritis (OA). A better understanding of their potential role in intervention strategies is required. The overall purpose of this thesis was to examine the interaction between lower limb alignment and body mass on dynamic knee joint loading, and to examine the effects of knee and foot orthoses, in patients with knee OA. The thesis included three studies. Chapter 2 was a cross-sectional study using three-dimensional gait analysis and full limb radiographs in 487 patients. Using sequential (hierarchical) linear regression, results indicated a statistical interaction between lower limb alignment and body mass on the external knee adduction moment, a proxy for the load distribution across the knee and a strong risk factor for OA progression. The relationship between alignment and the knee adduction moment depended on mass, with a higher association observed in patients with higher mass. Chapter 3 was a systematic review with meta-analysis of the biomechanical and clinical effects of valgus knee braces. Data were extracted from 38 articles. When pooling data, standardized mean differences suggested that braces provided a statistically significant decrease in the knee adduction moment during walking, and in patient-reported measures of pain and function, with overall moderate effect sizes. Substantial issues related to appropriate dosage, patient comfort and compliance were also identified. Chapter 4 was a proof of concept study that tested the combined effects of knee and foot orthoses. Sixteen patients with varus alignment and medial compartment knee OA underwent repeated three-dimensional gait analyses with and without wearing a custom-fit valgus knee brace, custom-fit lateral wedge foot orthotic, and both. Results indicated that the combined use of the knee brace and foot orthotic provided greatest reductions in the knee adduction moment. Overall, the results of this thesis emphasize the importance of considering alignment and the distribution of loads across the knee during walking when developing intervention strategies for knee OA. The present findings provide rationale for future research examining the combined use of different interventions that target biomechanics, including orthoses tailored to maximize biomechanical effects while maintaining patient comfort.
Moyer, Rebecca, "Alignment, Mass and Orthoses in Medial Compartment Knee Osteoarthritis" (2013). Electronic Thesis and Dissertation Repository. 1515.