Numerical study on biomechanical analysis of human lumbar spine in daily activities

The aim of this study was to establish and apply a framework that combines musculoskeletal modeling with motion capture data to investigate the biomechanics of the human lumbar musculoskeletal system during daily activities. By combining musculoskeletal modeling with motion capture data and performing inverse dynamics analysis, we quantified the compressive and shear forces on the lumbar intervertebral disc (IVD), total muscle force, muscle activation, and ligament forces during six daily activities (slow walking, walking, fast walking, sweeping the floor, washing windows, and standing on one foot). Our results showed that the mechanical loading on the lumbar IVD, muscles and ligaments increased with the increase of walking speed, and the mechanical loading on most lumbar tissues during sweeping the floor and washing windows was greater than that during walking. The mechanical loading within each tissue (including the lumbar IVD, muscles and ligaments) showed consistent distribution characteristics across different activities. Our study showed that sweeping the floor, washing windows, and increased walking speed resulted in higher mechanical loading on the lumbar IVDs, muscles, and ligaments. Our findings are important for understanding the biomechanics of the lumbar spine during daily activities.