Reconstruction of walking motion without flight phase by using computer simulation of the world elite 20km race walkers during official races

Abstract

BACKGROUNDS: Article 230 of competition rules of athletics specify
that race walking should be judged by human eye of the race walking
judges, but during races even highly skilled race walking judges may
sometimes not recognise a brief flight time as “Loss of Contact” time.
Electric or visual devices for race walking judge will be innovated and
applied to the race walking event. Then, the training methods to
avoid flight phase should be established. AIMS: The purpose of this
study is to obtain basic findings of the walking motion without flight
phase. From three- dimensional coordinate data of athlete in the
real official competition, virtual three-dimensional coordinate will be
calculated and the joint kinetics will be obtained by using inversed
dynamics. METHODS: Two kinds of computer simulation were
conducted on the three-dimensional whole body coordinates data of
sixteen world elite male walkers collected in the elite official race
(Olympic games held in 2004 and World championships in Athletics
held in 2005) for Men’s 20kmW. In most of elite race walkers, their
recovery phase time was larger than the support phase time. One
simulation directed to diminish the flight phase by setting the
recovery phase same as the support phase of contralateral leg.
Another simulation directed to diminish the flight phase by setting the
start of the support phase as the start of the recovery phase of
contralateral leg. RESULTS and CONCLUSION: In the simulation,
which directed to reduce the recovery phase time, the walking speed
was reduced because of the short step length. However, the larger
joint torque at hip and knee exerted rather than the real data. In the
simulation, which directed to expand the support phase time, the
walking speed was same as the real data. Although the large joint
torque at hip and knee exerted rather than the real data, the hip
abductors’ torque which was large in the walkers without flight phase
in the official race and experiment was reduced in the simulated
data. From these results, it is important large flexors’ and extensors’
torque at knee and hip were important to walk without flight phase.
However, the simulation in the frontal plane should be conducted in
the future.