Purpose/Hypothesis: 1) To describe feasibility of three tests of dual-task performance during walking for individuals with ABI. 2) To compare dual-task performance on the most feasible measure between subjects with ABI and a group of young adults.
umber of Subjects: 18 ambulatory adults (5 women) with ABI (age range 24–58); independently ambulatory for a distance of at least 40 feet (3 subjects used a cane or walker). Two subjects undergoing day treatment with recent onset were limited household ambulators. 16 subjects with chronic cognitive impairments required support for independent living; 14 were community ambulators. Comparison group subjects were 25 young adults (7 male) without brain injury (age range 22–35).
Materials/Methods: ABI subjects performed 1-‘Stops walking while talking test’(SWWT); 2-Walking While Talking Test (WWTT) that requires walking while repeating the alphabet and alternate letters of the alphabet; and 3-Walking and Remembering Test (WART) that tests speeded walking on a 12 inch narrow path while performing a working memory task. Dual-task costs on the WART were compared for the ABI and young adult sample.
Results: Task feasibility and difficulty for ABI subjects: The SWWT test was negative for all subjects. The alphabet WWTT task was easy for 89%, but the alternate alphabet task was too difficult for the majority (66%). The WART cognitive task was completed by all subjects, even those with severe declarative memory deficits. The WART walking task was not feasible for one subject who was legallyABI and young adult dual-task cost comparisons: WART median relative dual-task costs for walking speed were greater for ABI subjects [.18, 95% C.I. (.01, .24)] than young adults [.002, 95% C.I. −.02, .05)]. Mean reductions in digit span accuracy were similar [ABI subjects .87, 95% C.I. (.79, 95); young adults .92, 95% C.I.88, .95)]. Subjects with ABI had more difficulty with step accuracy on average, but the median dual-task steps off the path was zero for both groups.
Conclusions: Task difficulty is important when assessing dual-task perfor-mance. The SWWT and WWTT have limitations for ambulatory individuals with ABI, as the cognitive tasks are either too simple (SWWT) or too difficult (WWTT alternate alphabet cognitive task). Measures that allow for adjustment of task difficulty (WART) are feasible for individuals with cognitive impairment. The use of a working memory task revealed similar dual-task costs for cognitive task performance between the ABI and young.
Clinical Relevance: The diverse nature of deficits following ABI necessitates flexibility in outcome measures. Dual-task measures that record performance of both tasks and allow some adjustment of task difficulty may provide better insight into the effects of dual-task conditions and inform plans for intervention.