Reduced Sway During Dual Task Balance Performance Among People With Stroke at 6 and 12 Months After Discharge From Hospital

Background. Cognitive motor interference has been linked to poor recovery and falls. Little is known about recovery of dual-task balance ability poststroke. Methods. In this experimental study, postural sway was examined while standing on a force plate in preferred stance, with feet together, and with eyes closed, at 6 and 12 months postdischarge from hospital. Sway was assessed in isolation and while participants performed a cognitive (shopping list) task. Results . Seventy-six people with stroke (mean age 67 years; range, 21-91 years) took part. Fifty-four completed both assessments. When compared with the single task, sway during the dual-task condition was significantly lower in both the medial lateral (ML) and anterior posterior (AP) directions (both P < .0001). Sway in both directions was influenced by the difficulty of the balance task (both P < .0001). There was a trend of reduced sway at the 12-month assessment compared with the 6-month assessment: significant only in the ML direction (P = .0056). Repeat fallers swayed more than non—repeat fallers, with increases of 48% and 44% in the ML (P = .0262) and AP (P = .0134) directions, respectively. No significant variation in the dual-task reduction in sway was found: the dual-task effect was remarkably consistent over all the conditions tested, particularly in the AP direction. Conclusions. Sway decreased under dual-task conditions and changed as the difficulty of the balance task changed. Stroke fallers swayed more than nonfallers and there was evidence of a reduction in sway over time, particularly in the ML direction.