Method for Qualitative and Quantitative Assessment of Proprioceptive Perception of Single-joint Arm Movements

The phenomenon of reproduction of the series of passive single-joint movements in the tested arm by the contralateral arm just in the course of passive movements with no visual control was studied in 35 healthy subjects and 13 post-stroke patients in order to develop a new method for objective assessment of sense of the arm motion for the detection of proprioceptive deficit and for monitoring of the changes in proprioception during rehabilitation. We examined the reproduction of flexion–extension at the elbow and wrist joints, abduction–adduction at the wrist joint and the forearm pronation–supination in both right and left arms in healthy subjects and in the affected arm in post-stroke patients. Displacements of the angles in the tested joint and a homonymous joint of the other arm were acquired by means of video recording system, goniometers, or 9-DoF inertional-magnetometric sensors. Qualitative and quantitative indicators were evaluated to assess the similarity of the passive and active movements. It has been found that the healthy subjects are able to actively reproduce the repeated passive movements at different joints of either the left or right tested arm almost simultaneously and with quite accurate reproduction of an amplitude and shape of movement. At the same time, most of post-stroke patients reproduce movements either with qualitative errors demonstrating incorrect location or wrong estimation of direction or number of repeated test movements, or with significant reduction of accuracy (increased latency or shape distortion). We proposed a method for the assessment of movement proprioception at individual joints. The procedure is easy and convenient for both physicians and patients. It does not require special heavy equipment and can easily be performed under different conditions in a wide range of patients.