A team of researchers from the Netherlands examined the use of external lateral stabilization in people with lower-limb amputations. Their aim was to determine whether impaired balance control is partly responsible for the increased energy cost of walking for people in this group. The study was published online July 21 in the journal Gait and Posture.
The study cohort was composed of three groups:15 individuals with transtibial amputations, 12 individuals with transfemoral amputations, and 15 able-bodied controls. Each walked with and without external lateral stabilization that was provided through spring-like cords attached at the waist. Energy cost, step parameters, and pelvic motion were evaluated between groups. The researchers determined that participants with transtibial amputations and in the able-bodied group showed a small decrease in energy cost (by 5 percent and 3 percent, respectively, on average) when walking with stabilization; however, those with transfemoral amputations exhibited a 6.5 percent increase in energy cost. Step width, step width variability, and mediolateral pelvic displacement decreased significantly with stabilization in all groups, especially in group with transtibial amputations.
The study’s authors noted that, contrary to their expectations, external lateral stabilization did not result in a large decrease in the energy cost of walking among people with lower-limb amputations when compared to able-bodied controls, suggesting that balance control is not a major factor in the increased cost of walking in that population. Additionally, the increased energy cost for individuals with transfemoral amputations using stabilization suggests that restraining mediolateral pelvic motion impeded their necessary gait adaptations and thus negated the postulated beneficial effects of stabilization on the energy cost of walking.