Sensor embedded knee sleeve for post-operative ACL patients

Abstract

This paper describes a sensor-embedded knee sleeve designed to emulate the eye and coaching ability of a physical therapist by 1) taking accurate kinematic knee measurements and 2) incorporating the expertise of a physical therapist into feedback for the wearer. Patients recovering from ACL ruptures undergo a long rehabilitation process during which they work with a physical therapist to recover their normal gait pattern. However, research has shown that unnoticed gait irregularities can contribute to osteoarthritis later in life. Thus, these patients would likely benefit from gait observation and feedback outside of the therapist's office. The team developed a prototype of the knee sleeve using inertial measurement units (IMUs) placed above and below the knee to measure flexion angle. The team validated this method through testing with clinical-grade motion-capture technology. In the pursuit of providing feedback, the team developed a data processing script that is capable of recognizing gait and calculating metrics such as stride length, step count, flexion and extension angles, and others. Working with local experts in physical therapy, future efforts will focus on understanding how these metrics can be used to inform gait retraining.