Quantitative assessment of motor-proprioceptive deficits in nonparetic arm after stroke via a two-DOF passive manipulandum

Stroke is the leading cause of motor-proprioceptive in stroke survivors. The stroke rehabilitation is primarily focused on the paretic arm to achieve functional tasks. Only handful studies have targeted the non-paretic arm to understand its impact on the stroke rehabilitation. Hence, to further the literature, we attempted to quantify and compare the proprioceptive loss and motor pattern in both non-paretic and paretic arms after stroke. Here, we first present two degrees of freedom (DOF) manipulandum to quantify motor-proprioceptive deficits and next we present the motor behavior of both paretic and non-paretic arms after stroke as compared to healthy individuals. Ten healthy participants and seven stroke patients joined the study. Results showed that for healthy participants there was no statistically significant difference of the final position accuracy between the two arms in reaching different targets. On contrary, for stroke patients, there was a statistically significant difference between the two arms performance and in reaching different targets by either paretic arms (non-dominant) and non-paretic arms (dominant) in the workspace. Interestingly, stroke patients' non-paretic dominant arms did not follow the same motor pattern as for healthy participants. Altogether, we report significant loss of motor-proprioception in non-paretic arm in addition to paretic arm deficits after stroke. Therefore, we suggest that clinicians should consider non-paretic arm during rehabilitation to gain maximal recovery after stroke. Future investigations should be performed to consolidate these findings with a larger population size.