Development of the Myoelectric Control Resolution Assessment: A Rapid and Device-Agnostic Outcome Measure for Upper-Limb Prostheses

Myoelectric prosthetic hands and terminal devices are a standard of care for individuals with upper limb loss or congenital limb difference, typically controlled using surface electromyography electrodes. While numerous outcome measures exist to assess user performance with a myoelectric prosthesis, many are time-consuming and impractical for clinical settings. This paper introduces the Myoelectric Control Resolution Assessment (MCRA), a rapid and device-agnostic outcome measure requiring only a caliper, making it accessible even in low-resource settings. The MCRA evaluates the smallest volitional movements a user can generate with their myoelectric prosthesis, normalizing measurements to account for mechanical variability of the terminal device. Simulation results demonstrate the MCRA's ability to provide accurate, consistent, and unbiased control resolution estimates in as few as five measurements. The MCRA's simplicity and efficiency make it accessible to both prosthetic clinics and research organizations. It holds potential for clinical evaluation, myoelectric control algorithm comparison, training, and longitudinal studies, representing a novel advancement in the evaluation of myoelectric control fidelity and highlighting its potential for widespread clinical and research applications.