The modified drawing test for assessment of arm movement quality

Abstract

The cerebrovascular accident often results in motor impairment of one of the upper limbs, hence, compromising the quality of life of stroke survivors. Rehabilitation aims to restore the movement abilities of the paralyzed/paretic upper limb. An important element in rehabilitation is to apply a quantified measure of the quality of movement, in order to follow the recovery and select the most appropriate therapeutic modality. We developed a method that uses data recorded during planar movements and outputs an objective measure that relates to the smoothness, velocity and precision of the movement. This method is universal, in a sense that hand position can be recorded by any available means (e.g., robot assistant, digitizing board, motion tracking systems, etc). The method follows the Drawing Test, but generates results that show the ability of the patient to make point to point movements and track the presented trajectory. The method is based on measurements of hand position during movement along a target path in form of a 2 cm wide rectangle. The patient?s task is to move the hand along the target path as quickly as possible, with as few contacts (collisions) with the sides of the path. This paper addresses the aspects of automatic detection of parameters that quantify the quality of movement (speed, smoothness and precision). The use of this method is presented with 10 patients.