The influence of transtibial prosthesis type on gait adaptation: a case study

ABSTRACT Purpose Gait parameters are altered and asymmetrical in individual with transtibial amputation. The purpose of this study was to evaluate and compare the effect of four different prosthetic feet on lower-limb biomechanics during gait. Methods One young adult with transtibial ampution performed four gait analysis sessions with four foot-ankle prosthesis (Variflex, Meridium, Echelon, Kinterra). Kinematic, kinetic parameters and gait symmetry were analyzed during different prosthesis conditions. Results The type of prosthesis had little effect on amputee’ spatiotemporal parameters. Throughout the stance phase, an increase hip angle and a reduced knee flexion and ankle dorsiflexion were observed in the amputated leg. For kinetic parameters, a reduced propulsive force (SI=0.42–0.65), reduced knee extension moment (mainly during Echelon and Kinterra conditions, SI=0.17 and 0.32, respectively) and an increased knee abduction moment (mainly during the Variflex and Meridium, SI=5.74 and 8.93, respectively) in the amputated leg. Lower support moments were observed in the amputated leg compared to the unaffected leg, regardless of the type of prosthesis (SI=0.61–0.80). Conclusions The prostheses tested induced different lower-limb mechanical adaptations. If better gait symmetry between lower limbs is one of the clinical goals, an objective gait analysis could help clinicians to prescribe prosthetic feet based on quantitative measurement indicators.