Knee function assessment of anterior cruciate ligament injury with a Kirigami buckling‐resistant stretchable sensor

Continuous and quantitative monitoring of knee joint function has clinical value in rehabilitation assessment and the timing of return to play for anterior cruciate ligament injury patients. However, the existing approaches, including clinical examination, arthrometry and inertial solutions, can only be used for qualitative, off‐line and low‐quality evaluations, respectively. Burgeoning Kirigami stretchable sensors could be a disruptive candidate solution, but they usually suffer from structural buckling issues when used for large strain applications, such as knee joint motion capture where the buckling degrades sensor reliability and repeatability. Here, we propose a buckling‐resistant stretchable and wearable sensor for knee joint motion capture. It enables continuous and precise motion signal capture of the knee joint and provides high wearing comfort and reliability. Clinical tests were conducted on 30 patients in the field, tracking data provided by the sensor from their initial hospitalization to later surgery. And the full rehabilitation of one subject was recorded and analyzed. The test results show that our sensor can dynamically assess knee function in real time and recommend the best timing for return to play, which paves the way for personalized and telerehabilitation.