“…Similar work has used sensors on the distal shank or multiple sensors, 11,14,17,18,26 whereas this system is designed for all of the hip rehabilitation exercises to work with an IMU placed on the thigh, as currently many users may be prevented from reaching below the knee, particularly after total hip replacement. 38 The knee rehabilitation exercises have an IMU located at the midpoint of the shin, ensuring that users are able to place the sensor easily and maintain the same position for all exercises, although in both cases, further 'real-world' validation is required to ensure that IMU placement by untrained patients does not detract from accuracy.…”