Frontal-plane knee displacement index as a screening tool for risk of anterior cruciate ligament injury

Abstract

The aim of this study is to examine the potential of the two-dimensional posture evaluation method as a screening tool for detecting the high-risk population for anterior cruciate ligament injury. Eleven healthy adults participated in this study. They jumped from a 31 cm-high box and landed on their dominant leg. Three-dimensional knee flexion/extension, knee valgus/varus and hip adduction/abduction angle during single-legged landing were calculated. At the same time, the Frontal-plane Knee Displacement index (FKD)-the knee joint position relative to the line between the hip and ankle joint-was measured. FKD reflects the time variation of three-dimensional knee valgus and hip adduction angle very well. Our results suggest that FKD has potential as a screening tool particularly for movement occurring primarily in the frontal-plane.