Abstract: As a bionic therapy, hand-foot crawling has been reported to be used for the rehabilitation of low back pain. However, there have been few relevant biomechanical studies about this type of exercise. The purpose of this study was to calculate muscle activation and lumbar spinal load based on the examined limb kinematics and kinetics, which associated with hand-foot crawling at the different Centre of Mass (CoM) heights. A total of 14 men performed hand-foot crawling at three CoM heights. The kinematics and kinetics data were collected. One-way repeated measure analysis of variance was used to analyze the effect of the CoM height on crawling parameters. The crawling data from one subject at the three heights were used to calculate the muscle activation and compressive lumbar load with an OpenSim musculoskeletal model. The CoM heights had no significant effect on kinematics, kinetics or muscle activation. The spinal load was larger at higher heights. Hand-foot crawling was associated with lower trunk muscle activity. This study helps us to understand hand-foot crawling from the perspective of biomechanics. The findings from this study may help physical therapists choose hand-foot crawling as an appropriate exercise for patients with low back pain during early rehabilitation.

Key words: biomechanics, crawling, OpenSim, muscle activity, spinal load