Single-Arm Torque Perceptual Deficits in Individuals with Chronic Hemiparetic Stroke

Abstract

Single-Arm Torque Perceptual Deficits in Individuals with Chronic Hemiparetic Stroke BACKGROUND: To perform activities of daily living safely and efficiently, an individual with hemiparetic stroke needs to accurately perceive how much force is generated about their joints, i.e., torque perception. We know that individuals with moderate to severe motor impairments post hemiparetic stroke have between-arms torque perceptual impairments. However, a question that has yet to be addressed is whether these individuals have a torque perceptual impairment within their paretic arm and/or non-paretic arm. OBJECTIVE: To compare single-arm torque perception between individuals with chronic hemiparetic stroke and individuals without neurological impairments (i.e., controls). METHODS: Nine individuals with chronic hemiparetic stroke and five similarly-aged individuals without neurological impairments (i.e., controls) partook in the study. By following automated audiovisual cues, each participant generated 25% of their maximum voluntary elbow extension torque for three seconds, relaxed for two seconds, and then matched the remembered torque for one second without receiving feedback on their torque-matching ability. This torque-matching task was performed in each arm. RESULTS: The mean ± standard deviation of the normalized absolute torque matching error was 26.5±18.3% and 28.2±23.3% for the participants with chronic hemiparetic stroke in their paretic and non-paretic arm, respectively, and 19.8±7.1% and 20.1±11.3% for the controls in their dominant and non-dominant arm, respectively. Absolute error was not found to significantly differ depending on the arm tested (p=0.53). CONCLUSIONS: Our participants with chronic hemiparetic stroke and controls matched torques similarly in each arm. This result supports the notion that unilateral torque perceptual deficits may not occur in individuals with chronic hemiparetic stroke who exhibit motor impairments during unimanual activities.