Agreement Between Wrist Worn And Shoe Mounted Wearable Sensors On Spatiotemporal Outcomes Across Running Distances

Wearable sensors are popular for monitoring activity, especially spatiotemporal metrics in runners. Understanding the level of agreement for spatiotemporal outcomes between devices, and across different distances and environments, can help individuals when selecting wearables for their needs. PURPOSE: Assess agreement between wrist worn (WW) and shoe mounted (SM) wearable sensors on spatiotemporal outcomes during runs of different distances and environments. METHODS: 65 participants (age: 40 ± 14 yrs; BMI: 24.1 ± 4.4 kg/m2) completed three visits at self-selected effort: outdoor GPS measured 5 km run; indoor treadmill 5 km run; third visit varied by distance (2.5 km, 10 km, 20 km) and environment (indoor or outdoor). Participants wore a consumer smart watch on the left wrist and bilateral shoelace mounted inertial measurement units. Stride length (SL), average cadence (AC), peak cadence (PC), and ground contact time (GCT) measures were extracted from each device. Corrected SL (CSL) was calculated for WW to account for 1 vs 2 step counting difference between devices. Intraclass correlation coefficients (ICC) with absolute agreement were used to assess agreement between device outcomes. Paired t-tests assessed mean differences between devices. RESULTS: SL and CSL agreement were poor across trials (ICC range: .01 - .43), except CSL for 2.5 km (.77 - .72) and outdoor 20 km (.98) trials. Devices demonstrated excellent agreement for AC for all indoor trials (0.91-0.99) but varied for outdoor trials (.32 - .98) regardless of distance. Device agreement was poor-to-moderate for PC (.10 - .61) and GCT (.26 - .76) regardless of distance or environment. WW reported significantly lower SL, CSL, AC, PC, and GCT compared to SM (Figure). CONCLUSION: WW reports significantly lower spatiotemporal outcomes compared to SM. Runners should be aware of device discrepancies when selecting wearables for recreational use. Supported by: This study received funding from Samsung Electronics Co., Ltd.