COUPLING AND CROSSTALK CHALLENGES FOR GARMENT-BASED SENSOR CHARACTERIZATION: SENSING KNEE VALGUS USING A STITCHED STRAIN SENSOR WITH ANCHORING

Valgus angles during knee movements are a measure of interest both for rehabilitation and injury prevention applications. Soft, garment-like movement-sensing devices can improve patient experience with enhanced donning and comfort while supporting rehabilitation regimens and collecting valuable recovery metrics. However, textile-based sensing is generally less accurate than traditional methods for measuring joint angles. This study (n=3 participants) tested medial knee sensor responses during optical motion capture with prototype variants with and without circumferential anchors. Test participants performed non-valgus and valgus-induced squats. Correlation coefficients and regression were used to understand the relationships between knee valgus and sensor responses. Findings included mixed effects from anchoring, affected by participant and type of squat. Crosstalk from large flexion angles could be a primary contributor to the variability in medial sensor response. The ability to effectively sense and disambiguate these out-of-plane rotational effects remains a primary challenge for sensing complex movements with garment-integrated textile sensors.