Motion Analysis Evaluation of Knee Braces During Level Walking

Abstract

The purpose of this study is to evaluate the influence of two currently available rehabilitative knee braces on knee motion and their ability to protect against the knee displacement. Using the Eulerian angle, finite helical axis and three-dimensional motion analysis system, we measured all six degrees of freedom (DOF) of knee motion during level walking. The experimental group consisted of seven left anterior cruciate ligament deficient patients. Six normal subjects comprised the control group. Four test conditions were investigated: 1) injured limb; 2) injured limb with a range of motion (ROM) splint; 3) injured limb with 4-Point brace; and 4) control limb. Among the three knee joint angles, the maximal change induced by the brace occurred in flexion/extension, whereas the minimum occurred in abduction / adduction. Among the three translations, the maximal change appeared in the anterior / posterior displacement, whereas the minimum appeared in the medial / lateral displacement. Both knee braces were shown to significantly reduce three rotations and three translations of knee motion. The ROM splint restricted more knee motion than 4-Point brace, but no noticeable changes in the kinematic patterns, walking speed, and the percentage of left or right stance phase in the gait cycle could be demonstrated between two designs. In vivo measurements of translation of knee joint gave important information in the study of cruciate ligament injury problems or knee brace design.