Gait Evaluation of a New Electromechanical Stance-Control Knee-Ankle-Foot Orthosis

Abstract

Commercial versions of a stance-control knee-ankle-foot orthosis (SCKAFO) have emerged to improve gait over conventional knee-ankle-foot orthoses (KAFOs), which lock the knee in full extension in individuals with quadriceps muscle weakness. A new electromechanical SCKAFO was recently designed to address the functional, structural, and cost limitations of these commercial SCKAFOs. This paper presents an evaluation of the new SCKAFO conducted to determine its functional and clinical effectiveness during gait. Three healthy adults (100% male; age, 35.3 +/- 19.7y) and three KAFO users with knee extensor weakness in at least one limb (100% male; mean age, 56.3 +/- 4.0y) participated in the study. The SCKAFO had a minimal effect, as desired, on the kinematics of the able-bodied subjects. KAFO users had a mean increase in knee flexion of 21.1 degrees (sd=8.2) during swing, and a greater total knee range of motion when walking with the new SCKAFO compared to their prescribed KAFO. Two KAFO users experienced a reduction in pelvic obliquity and hip abduction angle abnormalities when walking with the SCKAFO compared to their prescribed KAFO.