Abstract
STUDY DESIGN: Retrospective analysis. BACKGROUND: The gait characteristics of transtibial amputees (TTs) have been described many times. In general, the literature reported nearly consistent results for the kinematic and kinetic parameters of the prosthetic side. However, the literature revealed inconsistent findings on kinetic parameters for determining the risk of developing knee osteoarthritis, such as the peak knee adduction moment, knee flexion moment and vertical ground reaction forces. OBJECTIVES: The objective of our study was to describe the sagittal kinetic and kinematic gait characteristics of the ankle and residual knee joint of the prosthetic limb and the knee loading parameters of the sound side of unilateral TTs. This specific consideration may contribute to resolving the controversy of these parameters in the literature. METHODS: We analysed our database containing gait analyses from 53 unilateral TTs and compared data to a control group (CG), also taken from our database. The sagittal kinetic and kinematic gait characteristics of the ankle and residual knee joint of the prosthetic limb, and selected knee loading parameters of the sound side (the peak knee adduction moment, knee flexion moment and vertical ground reaction forces) were evaluated. Beside these parameters we reported typical spatiotemporal gait parameters as gait velocity, step length, step length asymmetry, stance phase duration and asymmetry of stance phase duration. RESULTS: The TTs walked slower and more asymmetrically than the CG. The kinematic pattern of the prosthetic ankle differed from that found in the CG. The largest difference was observed for the range of motion of the plantarflexion at push-off, which was significantly reduced for the prosthetic foot. The residual knee joint was generally affected with respect to decreased moments and reduced knee flexion during stance phase. The peaks of the vertical ground reaction forces and knee adduction moments showed no differences between the sound side of amputees and the CG. The peak knee flexion moment at midstance was significantly reduced for the sound side of amputees in comparison with the CG. CONCLUSION: The biomechanical data measured for the prosthetic side in a cohort of 53 unilateral TT amputees conformed with the literature. The parameters determining the risk of developing knee osteoarthritis investigated in our retrospective analysis were not increased on the sound side in comparison with non-amputees. We deem it reasonable to assume that an appropriate prosthesis will reduce the likelihood of overloading the knee on the sound side during normal walking.