Estimation of Human Lower Extremity Musculoskeletal Conditions During Backpack Load Carrying

Abstract

Abstract. This paper focuses on the biomechanical aspects of the human lower extremity loading condition during backpack load carrying. A biomechanical framework was generated with the aim of employing a block-oriented structure of Simulink integrated with the Virtual Reality Toolbox of MATLAB software to provide a simulation study of the musculoskeletal system in a virtual environment. In this case, a ten-degrees-of-freedom musculoskeletal model actuated with sixteen muscles in each leg was utilized to simulate movement in the sagittal plane. An inverse dynamics based optimization approach was employed to estimate the excitation level of the muscles. In addition, distributions of the mechanical power analysis for lower extremity muscles were carried out to enhance the understanding of human leg morphology and control mechanism to provide load support. Simulation results provide a biomechanical framework to identify the muscles and joints, which are critically subjected to musculoskeletal injuries during the activity under investigation. Analysis of the muscle activation patterns and their distribution of the mechanical powers revealed the important role of the plantar exors of the ankle and the extensors of the knee and hip joints in supporting the body during backpack load carrying.