Dual-task related gait changes in individuals with trans-tibial lower extremity amputation

Background: The improvement of gait and mobility are major rehabilitation goals following lower extremity amputations. However, when living in the community many daily activities require the multitasking of motor and cognitive tasks. The dual-task paradigm can be used to evaluate the concurrent performance of mobility and cognitive tasks. Research question: The purpose of this study was to evaluate the effects of dual-task gait testing in older adults with trans-tibial amputations. Methods: Twenty-four people (15 men, mean age +/- SD, 62.72 +/- 8.59) with trans-tibial amputation walked on an electronic walkway at i) self-selected comfortable pace and ii) self-selected comfortable pace while counting backwards by threes from a number randomly selected between 100 and 150. Cognitive performance, in the form of corrected response rate, was also evaluated as a single-task. Results: The dual-task testing produced poorer performance in velocity (single-task=58.15 +/- 23.16 cm/s, dual-task = 50.92 +/- 21.16 cm/s, p = 0.008), cadence (single-task = 76.65 +/- 15.84 steps/min, dual-task = 67.85 +/- 15.76 steps/min, p = 0.002) and stride time (single-task = 1094 +/- 458.28 ms, dual-task = 1241.44 +/- 513.73 ms, p = 0.005). Step length, stance time and single limb support time symmetry were also affected, such that less time was spent on the amputated limb during the dual-task testing. Significance: Dual-task testing demonstrated interference resulting in a poor performance in both gait and cognitive performance in trans- tibial amputees. Further research is suggested to evaluate the change in cognition-mobility effects over time and the relationship of this value to future adverse events such as falls and successful outcomes such as community ambulation and reintegration.