Filmed at 15 km of an elite-level half marathon (283 runners analysed): 74.9% rearfoot, 23.7% midfoot and 1.4% forefoot strikers; in the fastest group of 50 the split was 62.0 / 36.0 / 2.0%, so midfoot striking became more common with speed, and rearfoot contact time was longer than midfoot + forefoot (200.0 vs 183.0 ms)
Four hundred fifteen runners were filmed at the 15.0-km point of an elite-level half marathon with two 120-Hz cameras 0.15 m off the ground; sagittal landing and take-off images were usable for 283. Runners were ranked and grouped in 50s by order at 15 km.
Participants
n=283 analysed of four hundred fifteen filmed; elite international field including Olympians. Sex split not given in the abstract.
Protocol
Video at 15.0 km; foot strike classified rearfoot (RFS), midfoot (MFS) or forefoot (FFS); contact time (CT) and apparent foot inversion (INV) at strike.
Key Results
RFS 74.9%, MFS 23.7%, FFS 1.4% of all runners; in the top 50 (up to the 69th runner, through 15 km in 45:53, 5.45 m/s or 15:17 per 5 km) RFS 62.0%, MFS 36.0%, FFS 2.0%.
The share of MFS was higher in the faster groups of 50.
CT rose with placement order (r = 0.71, p ≤ 0.05); CT for RFS was longer than for MFS + FFS (200.0 ± 21.3 vs 183.0 ± 16 ms).
Apparent inversion at strike in 42% of runners: 62.5% of MFS, 32.0% of RFS, 50% of FFS; CT with inversion for MFS + FFS was shorter than RFS CT with or without inversion.
Authors' speculation (economy was not measured): shorter contact and more inversion might contribute to better running economy.
Practical Application
Rearfoot striking is the norm even among elite half marathoners; a midfoot landing was more common in the fastest runners, but most of them still landed on the heel. Inference: no reason here to coach a runner off the heel.
Inference: shorter contact in faster runners is expected from speed itself; the race video cannot separate landing style from pace.
Limitations
One camera point (15 km) in one race; only 283 of the four hundred fifteen filmed runners could be analysed.
No statistics given in the abstract for the MFS-by-speed trend; running economy not measured.
Classification from 120-Hz video; sex and footwear not reported in the abstract.
How this entry was checked and changed
Why this level
cross-sectional race video; one point in one race, association only