InterACTION TM : Motion Tracking Device and Web-based Software for Rehabilitation of Knee Joint

By: Mirrah Almira - CMI Fellow  

Introduction: Adequate rehabilitation is the key for a successful recovery after total knee replacement surgery. Realizing its importance, a team of bioengineers, a surgeon, a physical therapist, and a business student at the University of Pittsburgh have worked together to create InterACTION TM , a new system to monitor and evaluate the patient's performance during rehabilitation.

[Pittsburgh, January 29, 2015] One of the challenges following total knee replacement surgery is ensuring patient compliance with a physical-therapy program during the period of rehabilitation. Since the clinical in-patient rehabilitation program often raises transportation issues to the patient, remote rehabilitation or home exercise for rehabilitation becomes the option that is more convenient for patients. In addition, physicians are unable to give enough patient motivation and patient-therapist communication. All of these problems hinder clinicians from creating personalized treatment plans for their patients.

Current approaches include the use of log books, mobile apps, or activity monitors in order to track the progress of the patients throughout the rehabilitation program. These approaches are insufficient because none of them can measure the quantity and quality of the joint-motion during exercise, while also provide corrective feedback for the patients.

InterACTION TM , on the other hand, provides all the things that are unavailable with current tools. InterACTION consists of a portable motion capture device and a web-based software application for recording and transmitting joint data. The motion capture device has sensors that enable the device to collect joint motion and position data. These data will be stored and analyzed by the software application, and then the results will be displayed in a customizable and joint-specific manner, on the mobile device such as tablet or smart phone. In this way, patients would be able to get visual feedback for the exercise they performed. Moreover, a web-accessible, password-protected portal will allow physical therapists to track their patients' progress over time, even remotely. Therapists will have easy access to the data to analyze patient progress and compliance, review computer-generated alerts, and also update the exercise if needed.

InterACTION allows therapists to be more efficient in providing care and improving patient outcomes. As for the patients, by getting quick and constant feedback, they will be more compliant with their prescribed exercise program and have a greater chance of recovery.

Collaborative work among bioengineers, scientists, and physical therapists has made InterACTION successful. Talented people behind InterACTION are:


A $25,000 grant from CMI throughout 2013 and 2014 has supported the team. By using this grant, the team has developed the platform for the mobile app, selected the appropriate sensor and software for the motion-tracking function, and performed studies to calibrate, optimize and validate the function of the InterACTION system.

Moving forward, the next goal for the InterACTION team is integration of the validated hardware with the software framework in order to produce a fully functional mobile prototype that is ready for clinical evaluation. (MA)