The effects of cognitive versus motor concurrent task on gait in individuals with transtibial amputation, transfemoral amputation and in a healthy control group.

Background: Lower limb amputation causes difficulties in mobility together with motor and sensory loss. Challenging situations such as concurrent tasks cause gait parameters to deteriorate. Understanding the effect of concurrent tasks on gait is important for the rehabilitation of amputees.

Research Question: Are the effects of concurrent cognitive and motor tasks on gait parameters at fixed speed different in individuals with transtibial amputation, or transfemoral amputation compared to healthy individuals?

Methods: The gait parameters were evaluated of 20 individuals with transtibial amputation, 13 individuals with transfemoral amputation and 20 healthy individuals while walking on a motorized treadmill under single task (ST), cognitive dual task (CDT) and motor dual task (MDT) conditions. The self-selected comfortable velocity, which was determined in the single-task gait, was used in all three walking tests.

Results: ST, CDT and MDT gait parameters of individuals with transtibial amputation, transfemoral amputation and healthy individuals were significantly different (p < 0.01). Covariance of step length variability increased in amputees when walking under MDT (p < 0.05). The dual task cost (DTC) for all the gait parameters was similar in all three groups (p > 0.05). The motor DTC of covariance of step length was greater than cognitive DTC (p < 0.05).

Significance: Individuals with lower limb amputation have the capacity to walk with cognitive and motor tasks without changing velocity on the treadmill, but concurrent motor tasks cause an increase in gait variability. The results of this study suggest that there is an increase in gait variability especially with motor tasks, which may cause a higher risk of falling. Trial number: NCT04392466 (clinicaltrials.gov).