Differences in quality of movements made with body-powered and myoelectric prostheses during activities of daily living.

BACKGROUND

Upper limb prostheses likely do not enable movements having the same kinematic characteristics as anatomical limbs. The quality of movements made using body-powered and myoelectric prostheses may further differ based on the availability of sensory feedback and method of terminal device actuation. The purpose of this work was to compare the quality of movements made with body-powered and myoelectric prostheses during activities of daily living.

METHODS

Nine transradial body-powered and/or myoelectric prosthesis users and nine controls without limb loss performed six activities of daily living. Movement quality, defined as duration, straightness, and smoothness, for the reaching and manipulation phases was compared between prostheses, as well as prostheses and anatomical limbs.

FINDINGS: The quality of reaching movements were generally similar between prostheses. However, movements with body-powered prostheses were slower (P = 0.007) and less smooth (P < 0.001) when reaching to a deodorant stick and movements with myoelectric prostheses were slower when reaching to place a pin on a corkboard (P = 0.023). Movements with myoelectric prostheses were slower (P ≤ 0.021) and less smooth (P ≤ 0.012) than those with body-powered prostheses during object manipulation, but these differences were not present for all tasks. Movements with prostheses were slower, more curved, and less smooth compared to those with anatomical limbs.

INTERPRETATION: Differences in the quality of movements made with body-powered and myoelectric prostheses primarily occur during object manipulation, rather than reaching. These differences do not exist for all tasks, suggesting that neither prosthesis type offers an absolute advantage in terms of movement quality.