Effect of upper extremity load on pelvic movements during wheeled upright walker use

[Purpose] This study aimed to elucidate the effects of upper extremity loading on pelvic movements during wheeled upright walker use. [Participants and Methods] Thirteen healthy male adults participated in this intervention study. Participants walked under five conditions with targeted loads on their upper extremities of 0%, 10%, 20%, 30%, and 40% of their body weights using a wheeled upright walker with armrests. Measured items included gait velocity and stride length; the angle of the maximum trunk anterior tilt; the range of motion of the trunk and pelvis in the movements of obliquity, tilt, and rotation; and the amplitude of the center of mass in the vertical and lateral directions captured and calculated using a three-dimensional motion analysis system. [Results] Increasing the load on the upper extremities did not shorten the stride or restrict pelvic movement during gait using upright walker use. The range of pelvic rotation with walker use increased versus that of the standard gait. [Conclusion] The pelvis showed quantitative movements during gait using the wheeled upright walker with armrests. These results could be helpful in the development of robotic assistive devices.