Quantification of tibiofemoral shear and compressive loads using a MRI-based EMG-driven knee model

• Published in: Journal of applied biomechanics Vol. 29; no. 2; p. 229
• Main Authors: Tsai, Liang-Ching, Scher, Irving S, Powers, Christopher M
• Format: Journal Article
• Language: English
• Published: United States 01.04.2013
• Subjects: Adult; Biomechanical Phenomena; Compressive Strength; Electromyography; Female; Humans; Knee Joint - physiology; Lower Extremity - physiology; Magnetic Resonance Imaging - methods; Muscle Contraction - physiology; Muscle, Skeletal - physiology; Patellar Ligament - physiology; Pressure; Shear Strength
• ISSN: 1543-2688
• DOI: 10.1123/jab.29.2.229

The purpose of this study is to describe an MRI-based EMG-driven knee model to quantify tibiofemoral compressive and shear forces. Twelve healthy females participated. Subjects underwent 2 phases of data collection: (1) MRI assessment of the lower extremity to quantify muscle volumes and patella tendon orientation and (2) biomechanical evaluation of a drop-jump task. A subject-specific EMG-driven knee model that incorporated lower extremity kinematics, EMG, and muscle volumes and patella tendon orientation estimated from MRI was developed to quantify tibiofemoral shear and compressive forces. A resultant anterior tibial shear force generated from the ground reaction force (GRF) and muscle forces was observed during the first 30% of the stance phase of the drop-jump task. All of the muscle forces and GRF resulted in tibiofemoral compression, with the quadriceps force being the primary contributor. Acquiring subject-specific muscle volumes and patella tendon orientation for use in an EMG-driven knee model may be useful to quantify tibiofemoral forces in persons with altered patella position or muscle atrophy following knee injury or pathology.