Recently Hasegawa et al (2007) investigated the foot strike patterns and ground contact times during a half marathon. They found that foot strike patterns were related to running speed with forefoot and midfoot strikers exhibiting shorter ground contact times and faster running speeds. The purpose of this study was to conduct a similar analysis in male 800m runners. Two seeded sub-elite female 1500 m races were filmed on one evening at a British Milers Club meeting. Twenty four runners were filmed by a 100-Hz video camera at a height of 15 cm placed 15 m from the start / finish line. All runners completed their race and were captured on all four laps of the race. Average race time showed a range of 46.21 s from 254.66 to 300.87 s with a mean 272.04 +/- 10.63 s and coefficient of variation of 3.9%. The mean contact time for laps 1 - 4 was 172 +/- 12 ms, 178 +/- 16 ms, 186 +/- 16 ms and 185 +/- 20 ms. On lap 1 20.8, 50.0 and 29.2% of runners made initial ground contact with the forefoot, midfoot and heel respectively. For lap 4 these values were 25.0, 41.7 and 33.3%. A two way ANOVA comparing ground contact time across the different races for each lap revealed significant main effects for lap (F3,66 = 12.367; P < 0.000) but not race (F1,22 = 2.151; P = 0.151). Those runners who displayed the same foot strike pattern on both laps (N = 18) were entered in to a 4x2 ANOVA comparing ground contact times by lap and foot strike position. This showed significant main effects for each lap (F3,45 = 7.014; P < 0.001) and foot strike position (F2,15= 4.372; P < 0.032). Post-hoc analysis revealed significant differences between the heel and midfoot contact points. The shortest ground contact times were for the midfoot (174 ms) followed by forefoot (179 ms) and heel (196 ms). Lap 1 had shorter ground contact times than any of the other three laps. Linear regression revealed a significant relationship between average running speed and average ground contact time however only a moderate portion of average running speed was accounted for (23.8%). This study found that foot strike patterns were related to average running speed. The relationship between ground contact time and running speed supports the notion of a spring-mass model of locomotion. Over the course of a 1500m race ground contact time increased irrespective of foot strike position. This implies an element of fatigue, with runners presumably requiring longer to generate the same impulse. Alternatively, this may have been a reflection of the pacing strategy during the races, with all races adopting a first lap that was quicker than average race velocity.
© Copyright 2009 14th annual Congress of the European College of Sport Science, Oslo/Norway, June 24-27, 2009, Book of Abstracts. Veröffentlicht von The Norwegian School of Sport Sciences. Alle Rechte vorbehalten.