Validation of Microsoft Kinect for Use in Detecting Balance Impairment in ACL Repaired Patients

The anterior cruciate ligament (ACL) is a critical part of normal knee function. With as many as 250,000 injuries every year, most of which occur through little or no contact, ACL reconstruction and rehabilitation are extremely important and relevant topics. One way to test a patient’s rehabilitation from ACL reconstruction is through the Star Excursion Balance Test (SEBT). A subject’s reach distance in the SEBT can be determined using motion capture systems. However, state of the art motion capture systems present some difficulties, such as cost and complexity of use. The Microsoft Kinect©, an inexpensive, markerless motion capture system, was predicted to solve the issues facing modern motion capture systems, while portraying acceptable levels of accuracy. It was also predicted that subjects who had undergone ACL reconstruction within the previous three months would not perform as well as controls in the SEBT. It was concluded that in most directions of the SEBT, the Kinect© performed within an acceptable range for use by clinicians in determining a patient’s advancement through rehabilitation. It was also concluded that the pathological subjects did not perform as well as controls. Future directions for this study include testing more pathological subjects and controls, as well as determining ways to capture more difficult directions of the SEBT