Pivot shift evaluation in the knee joint using inertial and magnetic sensors

The pivot shift test has been performed to assess the instability of the knee caused by anterior cruciate ligament (ACL) injuries. However, the test depends on the clinician´s subjective feeling. In this study, inertial and magnetic sensors have been introduced into quantitative evaluation of the pivot shift test. The analysis method extracts the knee movement of the pivot shift by using wavelet transformation. In the result of applying the proposed method to the ACL injured subject, pivot shift phenomenon was detected correctly in comparison with reference video images taken simultaneously, the mean of the maximum accelerations of the pivot shift was 2.19 ± 0.69 m/s², and the maximum accelerations were correlated with grade scores based on the clinician´s subjective feeling.