Biomechanical analysis of lower limb and trunk movements when lifting loads-investigation into differences in load weight

Abstract

[Purpose] In this study, human body movement when lifting loads of different weights was recorded, and the characteristics were investigated. [Subjects] The subjects were 13 healthy males. [Method] Human body movement when lifting loads was recorded using a three-dimensional motion analyzer. There were 3 types of load: no-load, 10 kg, and 15 kg. [Result] The vertical movement range of the physical center of gravity, the knee joint flexion angle, the hip flexion angle, the hip joint extension moment, and the ankle joint plantar flexion moment were significantly increased by lifting heavy loads. The acceleration of the physical center of gravity upward was significantly decreased when lifting heavy loads. There were no significant differences in the ankle joint dorsiflexion angle, the anteversion angle of the body trunk, the knee joint extension moment, and the velocity of the physical center of gravity among the different loads. [Conclusion] The knee joint flexion angle, the hip joint flexion angle, the hip joint extension moment, and the ankle joint plantar flexion moment increased in line with increasing load.