Uphill and downhill walking in unilateral lower limb amputees

Objective To study adjustment strategies in unilateral amputees in uphill and downhill walking. Design Observational cohort study. Subjects Seven transfemoral, 12 transtibial unilateral amputees and 10 able-bodied subjects. Methods In a motion analysis laboratory the subjects walked over a level surface and an uphill and downhill slope. Gait velocity and lower limb joint angles were measured. Results In uphill walking hip and knee flexion at initial contact and hip flexion in swing were increased in the prosthetic limb of transtibial amputees. In downhill walking transtibial amputees showed more knee flexion on the prosthetic side in late stance and swing. Transfemoral amputees were not able to increase prosthetic knee flexion in uphill and downhill walking. An important adjustment strategy in both amputee groups was a smaller hip extension in late stance in uphill and downhill walking, probably related with a shorter step length. In addition, amputees increased knee flexion in early stance in the non-affected limb in uphill walking to compensate for the shorter prosthetic limb length. In downhill walking fewer adjustments were necessary, since the shorter prosthetic limb already resulted in lowering of the body. Conclusion Uphill and downhill walking can be trained in rehabilitation, which may improve safety and confidence of amputees. Prosthetic design should focus on better control of prosthetic knee flexion abilities without reducing stability.