A Marker Set-independent Approach to Joint Translation Measurement of the Knee during Walking

Skin marker-based motion analysis has been widely used for understanding in vivo locomotion and pathological disorders of human musculoskeletal system in biomechanics research and clinical application. Since the knee joint translation is expressed as the displacement of pre-selected reference point on the femur relative to the tibia local coordinate system (LCS), the translation measurement is highly dependent on the selections of the reference point. In conventional motion analysis, they are often determined based on the marker set, which results in the marker dependent knee translation measurement (MDKT). Unfortunately, the location of bony landmarks which mostly are determined by palpation has limited accuracy and consistency which propagate to poor prediction of knee translation. In this study, we studied the sensitivity of knee translation measurement in response to the selection of different reference points. A marker set-independent approach (MIKT) was developed for the purpose of finding the optimal reference point for much smaller variances in knee joint translation measurements.