Individuals with Chronic Hemiparetic Stroke Correctly Match Forearm Position Within a Single Arm: Preliminary Findings

According to between arms position matching assessments, more than 50 % of individuals with stroke may have moderate to severe proprioceptive deficits. This study is the first of a series of studies designed to investigate the reason for observed between arms position matching deficits. In this work, we quantified the ability of five participants with chronic hemiparetic stroke (participants with stroke) and five age-matched participants without neurological impairments (controls) to match forearm positions within a single arm. According to the revised Nottingham Sensory Assessment, the participants with stroke all had impaired forearm position sense and unimpaired forearm movement direction sense, while the controls had unimpaired forearm position and movement direction sense. A custom robotic device was used to quantify each participant’s task performance during active movements when performing a single arm memory matching task. Participants were asked to match the location of the forearm with a remembered target location. Results show that the participants with stroke identified the target location just as well as the controls. Based on our findings, we suggest that our participants with chronic hemiparetic stroke, who have deficits in matching forearm positions across both arms, may not have impaired forearm position sense within a single arm, and we suggest that the position matching deficits may arise for non-sensory related reasons. Future work will continue to use such behavioral studies to investigate possible central neural mechanisms that may be contributing to the observed between arms position matching deficits.