Abstract
[Purpose] The present study was designed to examine the effects of movement speed on tracking accuracy of patients with stroke. [Subjects] Thirty stroke patients (16 patients with right hemiparesis and 14 patients with left hemiparesis, mean age = 56.2 yrs, mean period after stroke = 19.2 months) volunteered to participate in the study. [Subjects and Methods] Participants were required to track a continuous sinusoidal signal with rhythmic 3rd metacarpophalangeal (MCP) joint flexion-extension movements. The oscillation frequency of the signal was set at 0.2 Hz or 0.4 Hz with a total of 12 cycles per trial. The sinusoidal tracking signal and the participant's MCP motion signal were displayed overlapping together on a computer monitor. Participants performed 3 trials at each, 0.2 Hz and 0.4 Hz, frequency condition. [Result] Tracking accuracy was significantly less accurate under the slower 0.2 Hz condition when tracking the tracking signal with the paretic finger. [Conclusion] Participants were unable to efficiently track the external signal with the paretic side, suggesting that motor execution on the paretic side was significantly impaired. Moreover, the decline in the execution of the tracking movement with decreasing movement frequency might result from a failure of the feedback system to frequently update the impaired finger's movements.
