2013 Volume 4 Pages 17-21
Yoshikawa T, Shimada Y, Miyakoshi N, Matsunaga T, Hatakeyama K, Iwami T. Motion analysis of anterior inclination of the trunk while standing using a new three-dimensional musculoskeletal model combining the trunk and lower limbs. Jpn J Compr Rehabil Sci 2013; 4: 17-21.
Purpose: We developed a three-dimensional musculoskeletal model and used this model for motion analysis of the change in posture from standing upright to maximum anterior inclination of the trunk.
Methods: A new three-dimensional musculoskeletal model combining the trunk and lower limbs was constructed from a healthy volunteer. For motion analysis using this model, five healthy volunteers participated in this study. A three-dimensional motion analysis system was used to analyze the flexion phase from standing upright to maximum anterior inclination of the trunk, and the return phase from maximum anterior inclination of the trunk to standing upright. The muscle activities of the erector spinae, the rectus abdominis and the gluteus maximus were calculated from the motion analysis. The ratio of muscle activity at standing upright phase to the peak muscle activity was analyzed statistically for each muscle.
Result: The mean ratios of muscle activity at standing upright phase to peak muscle activity were 1: 3.94 ± 0.65 (mean ± SD) for the erector spinae, 1:1.75 ± 0.22 for the erector spinae, and 1: 4.07 ± 0.68 for the gluteus maximus. The muscle activity at standing upright phase and the peak muscle activity were significantly different in all muscles (paired t-test ; p < 0.0001).
Conclusion: A new three-dimensional musculoskeletal model combining the trunk and lower limbs is useful for simultaneous analysis of muscle activities of the trunk and lower extremities.
