Wavelet Transform Based Quantification of Pivot-Shift Testing Using Inertial and Magnetic Composite MEMS Sensor

Anterior cruciate ligament (ACL) injury and knee osteoarthritis are well-known injuries of the knee joint, and pivot shift is a symptom of the ACL injury. Today, to diagnose the pivot shift phenomenon, the manual testing is examined for the early diagnosis, however, it should be affected by inter- and intra observer variability. This article proposes a novel system for detecting and quantifying the pivot shift phenomenon during pivot-shift testing using inertial and magnetic composite micro electro mechanical systems (MEMS) sensor. The system estimated 3-D acceleration vector caused by the pivot shift phenomenon using wavelet transform. The experimental results indicated that the pivot shift phenomenon was detected and quantified. And, there are correlation between the maximum acceleration of the knee movement at the pivot shift and the conventional evaluation by assessors.