Infants and toddlers with amputations who require a prosthetic knee joint present a unique rehabilitation challenges to clinicians. Historicaly, infants and young toddlers with lower extremity loss at or proximal to the knee disarticulation level have been prescribed with a prosthesis with no prosthetic knee or a prosthetic knee unit locked in full extension. Two factors have contributed to acceptance of this treatment protocol: assumption that young children lack the strength and neural control to prevent the prosthetic knee from buckling, and lack of appropriately-sized pediatric prosthetic knee components. Most recently, pediatric prosthetic knees have been developed appropriate for infants and young toddlers and some centers have revised treatment protocols in order to fit very young children with a passively flexing prosthetic knee component. A gap remains in the evidence concerning the appropriate age for the introduction of an articulated knee in infants and toddlers. In addition, motor control research have identified mobility adaptations in crawling infants when their movements were restricted and when their environment was changed. The purpose of this study was to demontrate the kinematic and functional advantages of providing knee components in the first prosthesis of infants and toddlers with high level lower limb amputations. The working hypothesis is that infants and toddlers with knee disarticulation or trans-femoral amputation levels will demonstrate knee flexion functions paralleling their non amputee peers if provided with a free flexing prosthetic knee at first prosthetic fitting compared to diminished knee flexion functions if fitted with a non-articulating knee unit. In addition, the subject’s parents will report greater satisfaction in fit, function, and appearance of their child’s prosthesis in the unlocked condition.
