IMU-Integrated 'Smart' Knee Brace Validation Using Optoelectronic Motion Capture During Treadmill Walking

Optoelectronic motion capture systems are the gold standard for collecting kinematic data. However, these systems are expensive, occupy a large volume of space, and require training to operate. Inertial measurement units (IMUs) are small, portable devices that measure linear acceleration, angular velocity, and magnetic field and have been proven to be valid in measuring joint angles. A ‘smart’ brace was implemented with two IMUs and the knee joint angles calculated using data from the ’smart’ brace were compared to a gold standard motion capture system to assess the agreement and reliability of the brace. Ten participants visited the lab for two sessions, during which three 2-minute treadmill walking trials were conducted each session. The ‘smart’ brace had moderate to excellent reliability in measuring axial plane range of motion, and sagittal and frontal plane knee angles, but had poor agreement when measuring sagittal plane angles and frontal plane range of motion.