Motor coordination during body rotation while standing in healthy participants

[Purpose] To describe the nature of multi-joint motor coordination during body rotation while in the standing position. [Participants and Methods] The participants were 22 healthy adults with no visual problems or history of diseases that could compromise their ability to execute body rotation. The position facing forward in an upright standing position was defined as 0°, and targets were placed at the following five points on concentric circles: 30°, 60°, 90°, 120°, and 150°. The participants always turned to the right. A three-dimensional motion analyzer consisting of six infrared cameras was used to measure the spatial coordinates of the infrared reflective markers. [Results] A main effect was found for all body segments. For all the target angles, the start of movement was approximately equal, and the angular change of the craniocervical joint was the largest. A nonlinear relationship was observed between the craniocervical and thoracolumbar joints for all target angles. However, a linear relationship was found between the thoracolumbar and pelvic joints. [Conclusion] The results of this study demonstrate that various regions such as the craniocervical and thoracolumbar junctions and the pelvis coordinate during such move to achieve optimal locomotive patterns.