Dual-Tasking for Individuals with Lower Limb Amputation: Exploring the Relationship to Falls and Instrumental Activities of Daily Living

Veterans with lower limb amputation (LLA), particularly those due to vascular etiology, are at high risk to fall. Part of this high fall risk could be due to their reported need to focus on each individual step when walking, which makes adding a concurrent task (e.g., carrying an object) highly demanding. Everyday activities typically

require dual-tasking; therefore, problems with dual-task performance during daily life could account for the high number of falls for individuals with dysvascular LLA. In the older adult population, dual-task training (i.e., practicing two simultaneous tasks) improves simulated dual-task performance. Improving dual-task

performance could reduce fall risk during every day activities (e.g., getting dressed, moving while washing dishes, talking on the phone, or folding laundry). Veterans with dysvascular LLA need programs to improve daily activity performance, as they often experience a myriad of comorbidities and medical complexities

impacting participation in everyday life. Before a dual-task training program can be developed, preliminary relationships to dual-task performance need to be examined in this population. The long-term goal of this line of research is to implement novel dual-task interventions in the context of functionally relevant and ecologically

valid tasks for Veterans with dysvascular LLA. The initial steps toward the long-term goal are proposed with this study, in three aims, using an observational cohort and concurrent parallel mixed-methods design: (1) compare the proportion of participants experiencing mutual interference during dual-task walking between

fall groups (Non-fall vs. Recurrent Fall), (2) identify the relationships dual-task effects have with self-reported participation in activities of daily living, and (3) qualitatively explore the effects of dual-tasking on self-reported fall or near-fall dual-task scenarios. The quantitative phase (Aims 1 + 2) will identify how dual-task

performance relates to falls and participation in activities of daily living (n=30 Veterans with dysvascular LLA); dual-tasking will be measured with basic walking gait and cognitive tasks, as typically measured with other older adult populations. Dual-task performance will be measured using dual-task effects, a calculation of the

difference in gait and cognitive performance changes between the single and dual-task conditions. Gait speed (meters/second) will be measured and cognition will be quantified based on serial subtractions (corrected response ratio considering total responses and mistakes). The qualitative phase (Aim 3) will engage Veterans

with LLA (n=up to 30) to explore underlying cognitive and behavioral mechanisms that contribute to increased risk for falls. This CDA1 proposal is supported by infrastructure and resources from a parent Merit trial that is led by the primary mentor. The data gathered from this study will inform the development of a dual-task training

intervention trial (future CDA2 study) for Veterans with dysvascular LLA. During the award period, the candidate will capitalize on dedicated research time to develop clinical, research, and professional skills essential for a future role as a VA independent investigator. Specifically the candidate will develop greater

expertise in: research design and analysis (quantitative and qualitative), clinical training for Veterans with LLA, behavioral interventions, and scientific presentation (written and oral).