Changes in scapular and trunk angles and postural control during right-left hand-behind-back movement.

[Purpose] This study aimed to clarify the changes in the scapulothoracic joint and upper trunk angles and postural control during right-left hand-behind-back (HBB) movement. [Participants and Methods] The participants were 20 healthy right-handed men. We measured the HBB movement while standing using a three-dimensional motion capture system. Changes in the internal rotation angle of the scapulothoracic joint, upper trunk rotation angle, and center of pressure (COP) were examined to assess potential right-left differences between the analyzed positions. [Results] As the thumb touched the buttocks, upper trunk contralateral and scapulothoracic joint internal rotations were observed and the COP on the non-HBB side was significantly displaced laterally. There were no right-left differences in the changes between the analyzed positions for all measures. [Conclusion] Upper trunk contralateral rotation and postural control were conducted without right-left differences during HBB movement. These results suggest that upper trunk movement and standing postural control are involved in HBB movement. Therefore, it is useful to focus on the scapulothoracic joint angle, upper trunk rotation angle, and standing postural control during physical therapy evaluation and treatment with HBB movement.

Ankle, knee, and hip joint contribution to body support during gait.

[Purpose] Support moment was defined as the sum of ankle plantar flexion, knee and hip extension moments. There are some mechanical relationships among the 3 joints. If these relationships were understood, it might be possible to determine which joint should be strengthened to improve gait. The aims of this study were to examine the mutual relationship among kinetic variables of the 3 joints during different phases. [Subjects and Methods] Twenty-five healthy subjects volunteered for this study. They were asked to walk on a platform at a self-selected speed. Correlation coefficients between support moment and vertical ground reaction force were calculated for each subject. Pearson correlation analysis was performed among the 3 joint moments and between each joint moment and vertical ground reaction force. [Results] Knee and hip extension moments showed negative correlation throughout the stance. Ankle moment had a positive with hip but a negative correlation with knee moment except in the initial contact and pre-swing. Hip moment in the initial contact, knee moment in the loading response, and ankle moment from the terminal stance to pre-swing had a high correlation with vertical ground reaction force. [Conclusion] The results may indicate which joint should be strengthened to improve gait pattern.