Analysis of normal and spastic upper extremity movement utilizing a deceleration time constant

An engineering analysis technique, known as a phase-plane plot, is utilized to evaluate upper extremity motor performance of normal subjects and subjects with spastic activity. The bioengineering analysis technique is extended to analyze skeletal muscle performance during a manual tracking task. Specifically, we examine a redefinition of "time constant" with respect to its ability to distinguish between rapid commanded motor movement (C) from a rapid uncommanded motor movement (U) or "spasm".