Phase plane tracking: a new method for shaping movements.

Study of the relation between muscular activation patterns and movements has largely been based on the control of discrete movement parameters as amplitude, duration and maximum velocity. A new method is described for shaping voluntary limb movements in order to reliably obtain movements of different dynamic characteristics. A template of the desired movement is calculated with a micro-computer. This template is displayed on a storage oscilloscope as a phase plane (velocity vs. position during movement). By moving an instrumented handle the subject reproduces the template movement. Subjects readily adapt to this display and reliably make movements of different dynamic characteristics.