The Foot Shapes Of Youth Track Man Under Different Weight-bearing Conditions

The purpose of this study was to quantify the character of three-dimensional foot shape under different weight-bearing conditions. 97 youth track man in Beijing Sport University and 60 undergraduate students without histories of foot disease or injury in Isinghua University were selected in the experiment.A non-contacted foot 3-D laser scanner was used to obtained foot morphological data under four increasing loads:non-weight bearing,semi-weight bearing,full-weight bearing and full-weight-plus-20kg bearing.This research designed and captured 18 indexes,including length,width,circumference of foot, height of first metatarsophalangeal articulations,height of the arch of foot,height of instep,length of instep,height of internal malleolus, height of external malleolus,area of heel,etc.After statistics analysis of these indexes in different loading situation,foot morphological characteristics at different work loads were collected, which could provide both data and experiment practices support to the database establishment of foot morphological indexes of Chinese track man.By analyzing the foot indexes variances of athletes at different loads, some useful conclusions have been discovered.Firstly,different weight-bearing has influence on the foot shapes of youth track man. Secondly,there is marked difference on the foot shapes between youth track man and common undergraduates.Then,Sensitive and non-sensitive indexes were discovered.Length,width of foot,height of internal malleolus,height of external malleolus,height of medial longitudinal arch,etc.varied significantly with the increasing work load.For length of instep,width of heel,toe angles,no differences were identified between sets.While for some indexes,such as length of medial longitudinal arch,length of lateral longitudinal arch,height of first metatarsophalangeal articulations,there is no longer changing with increasing load after adapting to a relatively lighter load.There is marked difference on the foot shapes between different items youth track man,especially for the throwers.Finally,five dimensions of foot morphological characteristics were found to establish the foot-shape-index-system,which are respectively metatarsophalangeal index,heel index,ankle index,arch of foot index and length of foot index,including 15 items.