Effects of targets on reaching performance and postural balance during standing in persons with left cerebral vascular accidents

Purpose: The aim of this study is to investigate the effects of concrete vs. abstract tasks on reaching and postural performance during standing.—Methods: Twenty subjects with left cerebral vascular accidents (LCVA) and 15 age-matched healthy subjects performed the tasks under the target present vs. the target absent conditions with their less affected arm during standing. The condition of target present required the patients to push the glass forward as far as possible whereas the object absent condition involved reaching forward along the track as far as possible. The reaching performance was measured by forward reaching distance, and the postural control by derivatives of center of pressure (CoP) including forward displacement (FD), medial-lateral (M-L) shift, and average velocity (AV) of CoP.—Results: The LCVA group showed significant effects on reaching distance and AV of CoP. The control group demonstrated significant effects on AV of CoP.—Conclusion: The findings of this study partially support the notion that target present task optimized task performance. Beneficial effects were found on reaching distance and AV of CoP in healthy adults and on AV of CoP in LCVA patients, indicating LCVA patients demonstrated deficits in response to task target. These finding have implications for postural trainings in patients with stroke.