title: Dual-tasking interferes with obstacle avoidance reactions in healthy seniors.
abstract: Dual-tasking can lead to falls, as does a deterioration of obstacle avoidance (OA) skills. Hence, it is expected that a combination of both would be even more detrimental, especially when OA is time-critical. Previous studies confirmed this expectation, however, due to several limitations in their design it is yet too early to draw any definitive conclusions on the allocation of attentional resources in OA under dual-task conditions. Therefore, attentionally demanding primary and secondary tasks were used with the instruction to perform as well as possible on both tasks. Nineteen healthy senior individuals (60±4.7 years, 8 females) performed an OA task on a treadmill while walking at 3 km/h as a single task and combined with an auditory Stroop task. Biceps femoris (BF) muscle response times, OA failure rates and composite scores were used to evaluate the data. Increased OA failure rates (3%, p=0.03) and delayed BF response times (21 ms, p<0.001) were found under dual-task conditions. Composite scores were reduced during (p<0.001) and just after obstacle crossing (p=0.003). In conclusion, dual-tasking during time-critical OA affects the motor as well as the cognitive task when subjects are instructed to keep up performance on both tasks. This adds to the evidence indicating an increased risk of tripping or falling when attention is divided during walking in the presence of unexpected obstacles.
authors.affiliation: Department of Research, Development & Education, Sint Maartenskliniek, Nijmegen, The Netherlands. judith.hegeman@gmail.com
authors.forename: Judith
authors.initials: J
authors.lastname: Hegeman
authors.forename: Vivian
authors.initials: V
authors.lastname: Weerdesteyn
authors.forename: Bart
authors.initials: B
authors.lastname: van den Bemt
authors.forename: Bart
authors.initials: B
authors.lastname: Nienhuis
authors.forename: Jacques
authors.initials: J
authors.lastname: van Limbeek
authors.forename: Jacques
authors.initials: J
authors.lastname: Duysens
mesh_terms: D000058:Accidental Falls; D000161:Acoustic Stimulation; D001288:Attention / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D011597:Psychomotor Performance; D057190:Stroop Test; D016138:Walking / Q000502:physiology*