Fast cyclical movements of the forearm: a method to compute a novel preprogramming index

Evaluating the ability of movement preprogramming in elderly and in Parkinsonian subjects is known to be important for clinical diagnosis and for rehabilitation purposes. Employing cyclical two-target reaching tasks (Fitt’s tasks) a new cinematic analysis of forearm movements is performed [1]. We extract a new Index of Preprogramming (IP) which relates to the standardization of cinematic patterns. Another index (R2) quantifies nonlinearities [2] that on-line control introduces in the patterns due to corrective strokes. Present indexes can be employed together with known preprogramming indexes based on counts of corrective strokes [3] and they allow for a more accurate evaluation of the motor control strategies used by the subject.