The Influence Of Footwear And Running Surface On Foot-strike Pattern And Intuitive Running Speed

Studies comparing foot-strike patterns between shod and barefoot running often use a common intensity and/or surface. To the best of our knowledge, no study has observed runners’ intuitive running speed and foot-strike patterns across different intensities and surfaces while shod and barefoot. PURPOSE: To measure runners’ intuitive speed and foot-strike patterns when running at a variety of intensities (Rate of Perceived Exertion; RPE) on 2 different surfaces (Firm: track; Soft: grass) while shod and barefoot. METHODS: 40 recreational long-distance runners (24 males/16 females: 45.6 yrs ± 12.1; 171.4 m ± 7.7; 73.15 kg ± 11.18) were recruited. Each participant completed 4 sessions with a 1-week washout period between. In each session, participants began with a 6-minute warm-up (RPE 11) shod running on a tartan track, followed by a 3-minute rest. Participants then completed 4 conditions in a randomized order to mitigate order effect: shod on track, barefoot on track, shod on grass, and barefoot on grass. Each condition lasted 3 minutes with a 3-minute rest in between. Participants self-paced their speed to match the given RPE (Day 1: RPE 11; Day 2: RPE 13; Day 3: RPE 15; Day 4: RPE 17). Distance covered and foot-strike pattern were recorded in each trial. Speed was calculated as distance covered divided by three minutes (Speed = Distance ÷ Time). RESULTS: Runners covered the greatest distance when running shod on track across all intensities (Table 1). Foot-strike preference is correlated with footwear, F (2, 623) = 70.40, p < 0.001, η2 = 0.184, rather than speed or surface. While running shod, there was a higher prevalence of rearfoot strike (~93%) regardless of the surface or intensity used. Conversely, barefoot running showed an increased midfoot strike tendency (~33%). CONCLUSION: This study reports greater variability in foot-strike patterns while barefoot. This may be due to greater sensitivity to sensory stimuli as surface and/or intensity changes in the barefoot condition. Supported by: This research project is funded by the President's Fellowship Award from SETU Carlow.