Impacts of Sensation, Perception, and Motor Abilities of the Ipsilesional Upper Limb on Hand Functions in Unilateral Stroke: Quantifications From Biomechanical and Functional Perspectives

Background: The presence of subtle losses in hand dexterity after stroke affects the regaining of independence with regard to activities of daily living. Therefore, awareness of ipsilesional upper extremity (UE) function may be of importance when developing a comprehensive rehabilitation program. However, current hand function tests seem to be unable to identify asymptomatic UE impairments. Objectives: To assess the motor coordination as well as the sensory perception of an ipsilesional UE using biomechanical analysis of performance-oriented tasks and conducting a Manual Tactile Test (MTT). Design: Case-controlled study. Setting: A university hospital. Participants: A total of 21 patients with unilateral stroke, along with 21 matched healthy control subjects, were recruited. Methods: Each participant was requested to perform a pinch−holding-up activity (PHUA) test, object-transport task, and reach-to-grasp task via motion capture, as well as the MTT. Main Outcome Measurements: The kinetic data of the PHUA test, kinematics analysis of functional movements, and time requirement of MTT were analyzed. Results: Patients with ipsilesional UE had an inferior ability to scale and produce pinch force precisely when conducting the PHUA test compared to the healthy controls (P <.05). The movement time was statistically longer and peak velocity was significantly lower (P <.05) in the performance-oriented tasks for the ipsilesional UE patients. The longer time requirement in 3 MTT subtests showed that the ipsilesional UE patients experienced degradation in sensory perception (P <.001). Conclusion: Comprehensive sensorimotor assessments based on functional perspectives are valid tools to determine deficits in the sensation-perception-motor system in the ipsilesional UE. Integration of sensorimotor training programs for ipsilesional UE in future neuro-rehabilitation strategies may provide more beneficial effects to regain patients’ motor recovery and to promote daily living activity independence than focusing on paretic arm motor training alone.