Transhumeral prosthesis use and disuse affects whole-body angular momentum.

BACKGROUND

Individuals with transhumeral limb loss have an increased risk of falling, potentially resulting from altered upper-body kinematics during gait. The purpose of this study was to investigate whole-body angular momentum as a measure of movement control, to gain an understanding of how these upper-body kinematics contribute to dynamic balance.

METHODS

Eight participants with transhumeral limb loss and eight able-bodied control participants completed three gait trials at self-selected speeds. The participants with transhumeral limb loss performed trials with and without their prosthesis. Coefficient of cancellation and whole-body angular momentum about all anatomical axes of rotation were calculated. Means and variance were compared across the conditions over the gait cycle via statistical parametric mapping, and ranges were compared using a one-way ANOVA.

FINDINGS

Coefficient of cancellation was decreased between the upper/lower extremities in the transverse plane and between the upper extremities/trunk in the sagittal plane for both transhumeral walking conditions compared to the control group. Whole-body angular momentum was statistically different in the sagittal plane and decreased in the transverse plane when walking with the prosthesis compared to the control group. Walking without the prosthesis resulted in increased variability of whole-body angular momentum.

INTERPRETATION

Individuals with transhumeral limb loss had dysregulated whole-body angular momentum compared to the control group. This dysregulation was related to decreased segment-to-segment cancellation from the upper extremities and increased variance throughout the gait cycle. Based on these findings, individuals should be encouraged to wear their transhumeral prosthesis while walking as it may reduce fall risk and fatigue.