Assessment of Performance Using an Advanced Upper Extremity Prosthesis: A Case Report - Abstract
Background: As upper extremity prosthetic devices continue to advance, it is unclear if traditional outcome measures accurately assess their impact on function and quality of life. This case report describes the experiences of a military veteran with a transhumeral amputation utilizing the advanced DEKA prosthetic arm system.
Objective: Observe the performance of the DEKA Arm over one year; assess its impact on function using traditional outcome measures and subjective feedback from the subject.
Methods: Three previously validated assessment procedures on prosthetic hand control – viz., Box and Blocks Test (BBT), Southampton Hand Assessment Procedure (SHAP), and Assessment of Capacity for Myoelectric Control (ACMC) – were used as endpoints to compare the performance of the novel DEKA Arm System with that of the subject’s body-powered prosthesis. First, with the body-powered prosthesis that the subject had used for over four decades, a baseline occasion of assessment was observed. Next, the subject was fitted and trained with the DEKA Arm System and repeated the tests at eight occasions over one year. Then, the longitudinal trends of the indexed scores for each of the three functional assessments were estimated using ordinary least squares linear regression. Finally, a qualitative assessment was conducted to understand the overall impact that the DEKA Arm System had on the subject’s quality of life.
Results: Linear estimates of each of the three functional assessments suggested a gradual longitudinal improvement; however, the estimated effects were neither statistically nor clinically significant. Moreover, the subject’s performance with the DEKA Arm system at the exit assessment did not surpass that with the body-powered prosthesis at baseline. In the qualitative assessment, the subject held that the DEKA Arm system simplified many of his routine tasks and improved his quality of life when compared to the body-powered
prosthesis he had used for several decades.
Conclusion: This case report illustrates the likely disconnect between current upper-extremity prosthetic assessment tests and their ability to substantively capture a prosthetic’s impact on quality of life, functional performance, and body mechanics.