Precision Haptics in Gait Retraining for Knee Osteoarthritis (PhD Thesis Defense)

Gait retraining, or teaching patients to walk in ways that reduce joint loading, shows promise as a conservative intervention for knee osteoarthritis. However, its use in clinical settings remains limited by challenges in prescribing optimal gait patterns and delivering precise, real-time biofeedback. This thesis presents four interconnected studies that aim to address these barriers to clinical adoption: First, a regression model was developed to predict patient-specific biomechanical responses to a gait modification using only simple clinical measures, reducing the need for instrumented gait analysis. Second, we identified how inertial sensor accuracy fundamentally impacts motor learning outcomes during gait retraining, demonstrating the importance of reliable kinematic tracking. Third, we designed and validated an open-source wearable haptic platform called ARIADNE, which delivers precise vibrotactile motion guidance and enables rigorous comparison of feedback strategies for gait retraining. This platform's integrated sensing revealed how anatomical placement and tissue properties influence vibration transmission and perception. Finally, a gait retraining study demonstrated that vibrotactile feedback significantly improves both learning and retention of therapeutic gait patterns compared to verbal instruction alone, highlighting the critical role of precise biofeedback systems in rehabilitation. These contributions help advance the field's understanding of the sensorimotor principles underlying gait retraining while providing practical tools to support future clinical implementation.