Grant: Discovery Grants Program - Individual

Human joints are expected to withstand mechanical loads over the lifespan without suffering damage; however mechanics are clearly implicated in joint tissue degradation. Little in vivo work has explored the complex interactions of knee mechanics and joint tissues to distinguish between loading scenarios that promote versus degrade joint tissue composition. Even in healthy knees, a small amount of swelling in cartilage and a small volume of fatty infiltration of muscle can compromise mechanical properties of these tissues.My long-term research goal is to identify the ideal range of loading mechanics that promote the integrity of cartilage and muscle of the human knee. My short-term objective (next 5 y) is to systematically investigate the interactions of biomechanical strategies for mobility with muscle capacity and knee tissue composition in three inter-related streams. Specifically, I will:A) Reveal the mechanisms by which musculoskeletal capacity influences the biomechanical strategies used by healthy adults during practiced (walking) and unpracticed (bicycling) tasks. The role of load magnitude, load frequency and their statistical interaction on the proportion of muscle capacity used, as well as tibiofemoral contact forces, will be explored.B) Reveal the impact of intramuscular fat on muscle architecture and muscle capacity in healthy adults. The role of intramuscular fat volume on (i) the arrangement of muscle fibres, (ii) muscle torque and power outputs, and (iii) hip, knee and ankle kinetics during gait and bicycling will be explored.C) Define how biomechanical factors influence cartilage composition and adaptation in healthy young and healthy old adults. The role of load magnitude, load frequency and their statistical interaction on cartilage change will be explored.Trainees will develop critical skills in acquiring, interpreting and disseminating scientific data using state-of-the-art biomechanical and imaging instrumentation, as well as collaboration and leadership. Graduates will find these skills essential in careers in academia, research and industry.This work will produce highly innovative data revealing the mechanisms by which biomechanical strategies for mobility interact with muscle and cartilage composition of the human knee in vivo. A brand new approach to interpreting knee biomechanics will be featured: presenting joint kinetics relative to maximum musculoskeletal capacity. This approach will yield novel insights on how the capacity of the musculoskeletal system can influence joint biomechanics and joint tissues. This work will have an important and meaningful impact on future advances in the detection, management and treatment of musculoskeletal disorders such as osteoarthritis for Canadians.