KinetiClip - Wearable Gait Analysis System

KinetiClip is a wearable motion tracking system developed during the USC ASBME Makeathon to monitor gait asymmetry and toe-out angles in post-ACL reconstruction patients. ACL injuries account for 20.5% of all knee injuries, with 76% requiring surgical reconstruction and 18% of athletes experiencing reinjury, often caused by gait abnormalities lasting 6-12 months post-surgery. Our solution consists of three 3D-printed housing clips that mount to the user’s hips and affected heel, each containing a 9-axis IMU (including LPY503 analog gyroscope) connected to an Arduino microcontroller. These housings were designed in SOLIDWORKS for secure attachment to clothing and footwear to allow natural movement during natural analysis.

The sensor fusion algorithm was implemented in C++, sampling gyroscope and IMU data at 20Hz and processing it through a signal processing pipeline: zero-voltage calibration via 100-sample averaging at startup, 5-sample moving average filtering to reduce noise, and deadband thresholding (±0.5°/s) to eliminate gyroscope drift during stationary periods. Toe-out angles were calculated by the differential angular velocity between heel-mounted and pelvis-mounted gyroscopes, with numerical integration using overflow-protected calculations to track the foot’s rotational position relative to the pelvis. For gait asymmetry quantification, the IMU’s pitch rate was used to detect stride periods by identifying sign changes in hip joint rotation direction, calculating a symmetry index according to industry standards to provide PTs with quantitative metrics.

See our full presentation (including code) here