Article

Transradial body-powered prostheses are extensively used by
upper-limb amputees. This prosthesis requires large muscle forces and great
concentration by the patient, often leading to discomfort, muscle fatigue, and
skin breakdown, limiting the capacity of the amputee to conduct daily activities.
Since body-powered prostheses are commonplace, understanding their optimal
operation to mitigate these drawbacks would be clinically meaningful. OBJECTIVES:
To find the optimal operation of the prosthesis where the activation force is
minimized and the grip force is maximized. STUDY DESIGN: Experimental design.
METHODS: A computer-controlled robotic amputee simulator capable of rapidly
testing multiple elbow, shoulder, and scapular combinations of the residual human
arm was constructed. It was fitted with a transradial prosthesis and used to
systematically test multiple configurations. RESULTS: We found that increased
shoulder flexion, scapular abduction, elbow extension, and the placement of the
ring harness near the vertebra C7 correlate with higher gripper operation
efficiency, defined as the ratio of grip force to cable tension. CONCLUSION: We
conclude that force transmission efficiency is closely related to body posture
configuration. These results could help guide practitioners in clinical practice
as well as motivate future studies in optimizing the operation of a body-powered
prosthesis. Clinical relevance The results from this study suggest that
clinicians ought to place the ring harness inferior and to the sound side of the
vertebra prominens in order to maximize grip efficiency.
The results will also
help clinicians better instruct patients in body posture during prosthesis
operation to minimize strain.

Langue : ANGLAIS