How Does Dual Tasking Effect Gait In Individuals Who Use Prosthetics?

Prosthetic use alters gait and creates asymmetry, which leads to compensatory movements, impaired balance control, and increased fall risk. Common gait changes associated with prosthetic use are decreased gait speed, decreased stance time on the prosthetic limb, and decreased base of support (BoS). Dual-tasking (DT) during gait has been shown to have a negative effect on gait speed during forward walking (FW). Previously, individuals with mild cognitive impairments demonstrated greater gait variability and higher fall risk associated with DT. The impact of DT and backward walking (BW) on individuals with lower extremity amputations has not been studied. PURPOSE: To investigate the effects of DT and BW on the gait patterns of individuals that use unilateral (ULE) and bilateral lower extremity (BLE) prosthetics. METHODS: Six individuals with ULE or BLE amputation, at least six months experience using prosthetic(s), well-fitting prosthetic(s), and ability to walk and navigate curbs or stairs with or without using an assistive device walked the length of an instrumented walkway in forward and backward directions five times, each at a comfortable speed under single task (ST) and DT. For DT, participants counted backwards in increments, recited months in reverse order, or spelled a 5-lettered word backwards. Mean and coefficient of variability for stance time variability, step width, gait speed, single support center of pressure distance were analyzed using a 2-way repeated measures ANOVA. RESULTS: Gait speed was significantly lower while BW(p = 0.003) and DT(p = 0.015). Stride width was found to be significantly greater while DT(p = 0.01). Single support center of pressure distance was significantly smaller in BW(p = 0.001). Stance time variability was not found to be significant or have an interaction between FW and BW, and ST and DT. CONCLUSION: DT and BW significantly affected the participant’s gait speed, stride width, and single support center of pressure during gait. - Forward Walking Backward Walking Single Task Dual Task Single Task Dual Task Gait Speed (cm/s) 118.5 (14.8) 109.5 (19.0) 83.9 (16.2) 67.6 (21.1) Stride Width (cm) 19.8(4.5) 21.8 (4.8) 15.3 (4.1) 16.9 (2.7) Single Support Center of Pressure Distance (cm) 13.0 (1.1) 12.0 (1.8) 7.9 (1.4) 6.7 (3.0) Stance Time Variability (%) 4.1 (1.1) 4.3 (1.6) 7.2 (2.0) 8.9 (5.5)