A Longitudinal Study of Foot Strike Pattern in Children

Abstract

Foot strike pattern (FSP) is the distinction of how to contact foot on the ground during running, and it is distinguished for three patterns, fore-foot strike (FFS), mid-foot strike (MFS) and rear-foot strike (RFS). This has been one of topics of human movement researches in this several years. For example, RFS strike has a possibility to decrease running performance, and/or increase running related injury, because of its higher impact at the foot contact (Lieberman et al, 2010). FSP had been reported to differ from person to person, and was also reported to be influenced by running speed, that is, RFS strike at the lower running speed changes to FFS along with increasing running speed (Nigg et al, 1987). It was backed up by the fact that almost all the top-level sprinters in the world class contact with the fore part of foot (Krell & Stefanyshyn, 2006). On the other hand, it was reported that most of school children apt to strike with rear part of foot from the cross sectional study investigating FSP of children in elementary school (Tanaka et al, 2016). Then, this study aimed to investigate the relationship of FSP and spatial temporal parameters in relation to longitudinal changes in anthropometric parameters. Subjects were 20 school children consisted of 7 boys and 13 girls in this investigation. Measurements were longitudinally conducted from 2014 to 2017, in Chiba prefecture, Japan. Mean age, height and weight had changed from 7.4 to 10.4 years old, from 1.24 to 1.44 m, from 23.75 to 34.66 kg, respectively. They run for 50 meters in all their effort in time trials. Their running motion in sagittal plane was video captured with high-speed camera (120 fps) from left side of the runway. The section of video capture was from 32 m to 38 m of the runway. The captured movies were analyzed thereafter using computer software. FSP were distinguished from left legs of the subjects for 3 types of strike pattern, FFS, MFS and RFS. Running speed, step frequency, step length, contact time and flight time were calculated from the frame of the movies. Table-1 represents FSPs and mean±SD values of spatial temporal parameters. Differences in mean values of each parameter were compared with t-test. As results of statistical analysis, significant differences were shown in running speed and stride length, not only height and weight between 2014 and 2017. Contrary, no significant differences were seen in FSP, step frequency, contact time and flight time.