Shaping synergistic pinching patterns with feedback distortion in a virtual rehabilitation environment.

Individuals with chronic disabilities often use compensatory coordination patterns learned during the recovery phase, even after their individual muscular control returns. Although these compensatory movements limit their ability to complete tasks, these individuals are not able to relearn the correct synergistic coordination patterns because doing so would temporarily compromise task performance. Following our previous work using feedback distortion in a virtual rehabilitation environment to increase the strength and range of motion of disabled individuals, we address the use of this same feedback distortion environment to alter movement coordination patterns. In this paper, we present the methodology and preliminary results showing that (1) able-bodied individuals could be trained to use a different coordination pattern to produce pinching movements, and (2) feedback distortion can alter movements for individual fingers separately during a coordinated movement. These results indicate that our distorted virtual environment may be a powerful rehabilitation tool to convert compensatory movements into movements that utilize all muscles in the normal synergistic patterns.