title: Community-dwelling people with chronic stroke need disproportionate attention while walking and negotiating obstacles.
abstract: The objective of the present study was to examine the attentional demands of gait adaptations required to walk over irregular terrain in community-dwelling people with chronic stroke. Eight community ambulators (>6 months post-stroke, aged 57 ± 15 years) and eight age-matched healthy controls participated in the study. As the primary motor task, participants walked on a treadmill while they quickly reacted to a sudden obstacle in front of the affected (in the stroke group) or left (in healthy controls) leg. The secondary, cognitive task was an auditory Stroop task. Outcomes were avoidance success rate and muscle reaction times of the biceps and rectus femoris (motor task), and a composite score of accuracy and verbal reaction time (cognitive task). Success rates did not differ between single- and dual-task conditions in either group, while muscle reaction times deteriorated equally during the dual task in both groups. However, compared with the Stroop scores just before and after obstacle crossing, the scores while crossing the obstacle deteriorated more in the stroke group than in the controls (p=0.012). The higher dual-task costs on the Stroop task reflect greater attentional demands during walking and crossing obstacles. The absence of dual-task effects on obstacle avoidance performance suggests that the people with stroke used a "posture-first strategy". The results imply that common daily life tasks such as obstacle crossing while walking require disproportionate attention even in well-recovered people with stroke.
authors.affiliation: Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Neurology, Nijmegen, The Netherlands.
authors.forename: Katrijn
authors.initials: K
authors.lastname: Smulders
authors.forename: Roos
authors.initials: R
authors.lastname: van Swigchem
authors.forename: Bert J M
authors.initials: BJ
authors.lastname: de Swart
authors.forename: Alexander C H
authors.initials: AC
authors.lastname: Geurts
authors.forename: Vivian
authors.initials: V
authors.lastname: Weerdesteyn
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001288:Attention / Q000502:physiology*; D016022:Case-Control Studies; D002908:Chronic Disease; D005080:Exercise Test / Q000379:methods; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology; D010775:Photic Stimulation; D004856:Postural Balance / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D012016:Reference Values; D012111:Residence Characteristics; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications* / Q000175:diagnosis; D000071939:Stroke Rehabilitation; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology*