In the United States, thousands of patients are admitted into emergency departments due to work-related musculoskeletal knee injuries, many caused by overexertion from extended period of squatting, heavy lifting, and climbing. Significant structural injuries of the knee often require multiple surgeries and long rehabilitation periods. The postoperative progress made by patients during rehabilitation is largely self-reported, as is the extent of physical strain a worker experiences. Overexertion and inattentive rehabilitation may be prevented through continuous quantitative monitoring of patients’ physical activity and rehabilitation progress. However, systems to actively monitor the biomechanics of a knee throughout the rehabilitation process or workday in a continuous manner are not currently available.
We have developed a device of textile strain sensors integrated into a knee brace to provide this continuous monitoring. Mechanical and electronic characterization of resistive and piezoelectric textile sensors developed for this application will be presented. Prototype devices including biomechanical data and design considerations for comfort and performance will also be presented. Preliminary correlations between strain data and rigorous knee flexion movements will also be discussed with implications for knee injury prevention and recovery monitoring. These developments, while targeted for knee flexion monitoring, can be translated to many common physical ailments including ankles, wrists, elbows, shoulders, and backs.