Abstract
[Purpose] The purpose of the present study was to investigate arm selection behavior of stroke patients in a wide range workspace when they reached for an object. [Subjects] Twenty-three patients with stroke were recruited. The participants consisted of 10 right hemiplegic patients and 13 left hemiplegic patients. All participants were self-reported right-handed persons who were able to understand and respond to directions given by the experimenter. [Methods] Participants were instructed to reach to a target with the preferred hand at comfortable reaching speeds when nine targets randomly appeared on a table. The nine targets were located at the body midline (labeled 0 degrees), -10 degrees, -20 degrees, -30 degrees and -40 degrees to the left of midline, and 10 degrees, 20 degrees, 30 degrees, 40 degrees to the right of the body midline. Each participant's upper-extremity sensorimotor, somatosensory, cognitive, and ADL functions were also attained. [Result] We found three distinct arm selection patterns. Sixteen patients who had relative good muscular strength and sensorimotor functions were characterized by a "normal-like" arm selection pattern. Five participants mostly used their non-paretic arm to reach to all targets, and three participants were characterized as having no pattern in arm selection behavior. [Conclusion] The most important factor that determines normal-like arm selection behavior of stroke patients in reaching is the integration of cortical sensory function and muscular strength. Purposeful use of the affected limb through with sufficient muscular strength will play a crucial role in achieving normal-like arm selection behavior.