Effect of Dynamic Tightening Force by Active Corset on Joint Stiffness and Lumbar Assisting

Abstract

In this paper, we experimentally verify the relationship between the change in the stiffness of joints around the lumbar due to dynamic tightening control of the Active Corset and the reduction of the lumbar load. The bending angle of joints around the lumbar in lifting movement were measured, and the elasticity of the joints were calculated. As the result of the measurement on 21 subjects, tightening of Active Corset reduced the lumbar load with substituting the lumbar joint flexion by the hip joint flexion in all subjects. In addition, the we confirmed that the ratio of the lumbar elasticity to the hip joint elasticity increase with tightening around the pelvis on the four subjects. We conclude that the decrease of the lumbar load with tightening caused by increasing the ratio of the lumbar joint elasticity to the hip joint elasticity.