Comparison Of Running Gait Variability During Treadmill Versus Overground Running Using Lace-mounted Wearable Sensors

Instrumented laboratory running analyses are the gold standard for gait assessment but may not accurately capture the variability of overground running. Consumer-grade wearable sensors enable running gait analyses during indoor and outdoor training and allow for comparisons of biomechanical variability across environments. PURPOSE: Assess variability and limb differences in spatiotemporal, kinetic, and kinematic running biomechanics between- and within- treadmill and overground running over a 5 km distance. METHODS: 51 recreational runners (22F, 29 M; age: 37 ± 11 years; BMI: 22.9 ± 3.6 kg/m2) completed an outdoor 5 km run on a level standardized route followed by a 5 km treadmill run 13.7 ± 4.7 days apart. Participants ran at self-selected moderate training paces (3.5 ± 1.0 m/s) with bilateral lace-mounted wearable sensors. Sensor-derived metrics included spatiotemporal, kinetic, and kinematic measures. Runs were filtered to remove walking data (flight ratio < 10%) and segmented into thirds by time. Coefficients of Variation (CV) were calculated for all metrics to determine variability ([Standard Deviation/Mean] *100). General linear models were used to compare average biomechanics and CV between run environments and limbs, and changes across three equal run segments, covarying for pace. RESULTS: Spatiotemporal, kinetic, and kinematic mean outcomes differed significantly between environments (p < 0.001; Table). Stride length was significantly longer in the first versus other run segments (Mean Difference [MD] range: 2.7-3.4 m; p < 0.001). CVs were significantly higher for most metrics during indoor running (MD range: 0.26-3.78, p-range: < 0.001-0.02; Table). No significant interlimb differences were noted. CONCLUSIONS: Increased running gait variability during indoor running may be a result of adaptations to fit the physical constraints of a treadmill system compared to overground level running. This study was funded by Samsung Electronics Co., LTD.This study was funded by Samsung Electronics Co., LTD.