###### Abstract  
Postoperative home-based rehabilitation programs are essential for facilitating functional recovery after total knee replacement (TKA). This study aimed to verify the feasibility of applying a wearable motion sensor device (MSD) to assist patients in performing home-based exercises after TKA. The interrater reliability of the measurement for knee mobility and the time spent completing the 5-times sit-to-stand test (STSST) by two experienced physicians and using the MSD in 12 healthy participants was first assessed. A prospective control trial was then conducted, in which 12 patients following TKA were allocated to two groups: the home-based exercise group and the MSD-assisted rehabilitation group. Changes in knee range of motion, pain, functional score, performance, and exercise completion rates were compared between the groups over two months of follow-up. MSD-measured knee mobility and STSST exhibited excellent reliability compared with the physician measurements. Furthermore, patients in the MSD-assisted rehabilitation group reported higher training compliance than participants in the home-based exercise group, which led to better outcomes in the knee extension angle and maximal and average angular velocity in STSST. MSD-assisted home-based rehabilitation following TKA is a feasible treatment model for telerehabilitation because it enhances patients' compliance to training, which improves functional recovery. k 202  
postoperative discomfort and accelerating functional recovery in patients after TKA [8; 9]. Protocols to improve post-surgical recovery have led to a decrease in the length of hospital stay among patients after arthroplasty [10]. The time for inpatient rehabilitation after TKA is thus decreased, highlighting the need for guidance on home-based rehabilitation for patients. However, the provision of post-hospital rehabilitative care is highly variable, and the barriers to accessing therapists and the financial burden of rehabilitation services should be considered, given the demand for high-quality rehabilitation services following TKA [11]. In-home exercise programs are easily accessible self-training programs that can be performed by patients, and they have similar effectiveness to inpatient rehabilitation programs following TKA [12]. However, the success of functional recovery depends on the patients' training compliance and in-home exercise correctness. Research has demonstrated that physical activity does not increase in patients following joint replacement [13], and only a quarter of patients with OA comply with their exercise program [14]. Developing more reliable methods to maximize the effectiveness of home-based physiotherapy remains challenging. Techniques for detecting body motions could be employed to monitor and rehabilitate disabled patients, offering independent training that has advantages over traditional rehabilitation services [15]. Inertial measurement units (IMUs), including accelerometers and gyroscopes, have been extensively used in technology-assisted rehabilitation with sufficient accuracy [16; 17; 18]. The IMU-based motion tracking systems, which can be used to reconstruct the position or the orientation of the body they are attached to, have the advantage of cost-effectiveness and wearability, allowing for long-lasting tracking of the user motion in situated environments [19]. In our previous study, we developed a wearable motion sensor device (MSD) utilizing the wearable IMU-based sensors to trace the shoulder's angular motion to assist with in-home shoulder exercises for patients with adhesive capsulitis [20]. In addition, the design of the MSD was integrated with interactive mobile apps through wireless telecommunication technology to increase patient-provider interaction, thereby supporting the feasibility of image- and sensor-based telerehabilitation in the treatment of adhesive capsulitis. Our results demonstrated preliminary success in increasing patients' adherence to daily rehabilitation programs, which facilitated shoulder functional recovery.