Biomechanical analysis of users of multi-articulating externally powered prostheses with and without their device

Abstract

Background: Loss of the hand results in significant functional deficits and requires adaptation of movement patterns which may result in overuse injuries. An externally powered prosthesis may improve function of the affected limb and reduce the overreliance on the intact side; however, little research has been done in this area. Objective: Investigate changes in upper limb function and kinematics in individuals with partial-hand amputations performing a functional assessment by comparing results with and without a multi-articulating hand prosthesis. Study design: Cross-sectional. Methods: Three-dimensional kinematics of four- and five-digit limb loss participants were collected as they performed the Southampton Hand Assessment Procedure with and without a prothesis. Results: Ten males completed the protocol: five with four-digit loss (thumb intact) and five with five-digit loss. Significantly larger joint motions were seen without the prosthesis than with for all participants, which may be an indicator of higher risk for overuse injury. Significant improvement was seen in Southampton Hand Assessment Procedure scores in the five-digit limb loss participants using the prosthesis compared with not using the device (p < 0.05 for 6/7 Southampton Hand Assessment Procedure score categories). Conclusion: The prosthesis reduced functional deficits and decreased joint range of motion in individuals with partial hand loss. Results showed reduced compensatory motions throughout the upper limb and torso which may reduce the risk of overuse injury. Clinical relevance Results of this study indicate that externally powered partial hand prostheses can be effective in improving function and reducing compensation in individuals with partial hand loss.