Neuromechanics Projects
Neuromechanics
Investigation of the role of joint sensory information in motor control of the joint, specifically in relation to joint stability. Experimental quantification of the neurophysiological function of the periarticular tissue afferents would elucidate their relationship to the mechanical stability of the joint. Such measures can be used to determine how training influences the contributions of mechanical and neurological components to joint stability. This information will be clinically relevant to interventions limiting the progression of osteoarthritis. The ability of the knee muscles to produce varus/valgus moments strongly indicates a need for neural control mechanisms to maintain stability in this joint direction (publication in progress; see Figure 1) Future experiments will be focused on the development of input/output models of the joints periarticular tissue afferents. Utilizing the source localization technique that my colleagues and I developed (Ricamato et. al., 2000), a further investigation on the neurphysiological source of these afferents will be conducted.
A comprehensive neuro-musculoskeletal knee model was also developed to serve as a theoretical framework for the experimental data (Dhaher et. al. 2000; Dhaher & Kahn, 2000). Further development of the knee musculoskeletal model has led to the determination of the feasible varus/valgus control space of the quadriceps muscle at the knee (publication in progress). Elaboration of the model will incorporate feedback elements (muscle and periarticular tissue afferents) in addition to the traditional biomechanical components.
Orthopaedic Biomechanics
Development of predictive musculoskeletal models for multi-degrees-of-freedom dynamic simulations.
Design of artificial joints: The growth of the high tech orthopedic implant industry has increased the need for high precision, accurate and inclusive musculoskeletal models of the human joints. However, the dynamic performance of currently employed joint implants is hindered by several insufficiencies in the joint design: poor representation of the contact surface topologies, inadequate muscle models and inaccurate representations of the wrapping of musculoskeletal tissues over the underlying morphology. My future focus will be on the improvement of joint musculoskeletal models that can be used in simulation and design of artificial joint mechanics.
A comprehensive biomechanical model of natural joints: the primary mission here is to study normal and pathological joint function, which can be ultimately applied to the improved evaluation and treatment of musculoskeletal joint disease and injury. For example, our model based simulations pointed to the intricate role of the combined VML and VMO muscles in reducing the lateral contact forces, factors contributing to patello-femoral pain (Dhaher & Kahn, 2000; see Figure 2) My future research will focus on the development of a complete subject-specific analytical study that defines the optimal combinations of VML/VMO, and possible other quadriceps muscles, that minimized lateral contact patello-femoral contact forces.