Relationship between level of amputation and compensatory gait strategy

Objective Gait biomechanics changes after lower limb amputation. This study aims to determine how amputation level may impact gait biomechanics and compensatory behaviour in people with unilateral amputation. Study design Observational study. Setting Laboratory. Participants This study included eight participants with unilateral transtibial amputation, 10 individuals with unilateral transfemoral amputation, and 11 older persons with no history of amputation. Main outcome metrics Gait kinetics and kinematics. Results The transfemoral group significantly walked slower compared to the older persons (p-value = 0.005). Knee adduction moment on intact side was greater during midstance in the transfemoral group compared to the transtibial (0.16 ± 0.16 Nm/kg). The older persons showed greater hip adduction moment on the amputated side during initial midstance compared to those in the transfemoral (0.28 ± 0.18 Nm/kg) and transtibial (0.21 ± 0.16 Nm/kg) groups. The transtibial group demonstrated greater lateral trunk flexion towards the intact side during initial contact (4.08 ± 4.05°) and swing phase (4.36 ± 3.66°) compared to older persons. The transfemoral group also had greater lateral flexion towards the intact side during early swing (2.78 ± 2.70°) compared to older persons. Conclusions Both groups of transtibial and transfemoral used trunk lateral flexion toward their intact side as a compensatory behaviour to enhance stability and minimize activation of the hip abductors, which can contribute to lower back pain. The increased knee adduction moment in the transfemoral group indicates a higher risk of knee osteoarthritis. Rehabilitation and physical therapy may prove beneficial in improving muscle strength, which can lead to better gait mechanics.