Ivory Towers: Walking back to happiness

A FAT and jovial fellow I once knew used to win money by challenging athletic types to sprint races. First he would suggest that his fitter opponent should run twice as far as he, but then he offered to compromise by running backwards. Apparently any fat fellow can bound along backwards for 50metres more quickly than a great sprinter can manage 100.

This is not covered in Changes in Sprint Stride Kinematics With Age in Master's Athletes, a study by Nancy Hamilton in the February 1993 Journal of Applied Biomechanics. From videotapes of 162 sprinters, aged 30 to 94, calculations were made of velocity, stride length, stride period, support time, swing time, flight time and hip, knee, and trunk range of motion.

'Stride length divided by stride period produces the kinematic measure sprint velocity. Any alteration in stride velocity must be a direct result of a change in stride length, stride period, or both.' Earlier studies had shown a decline in sprint velocity with age, but this one aimed to find out whether it was due to a shorter strides or an increase in stride period.

The main result was 'that the primary alteration in stride velocity that takes place with ageing is a decrease in the length of the stride rather than in the amount of time used for each stride . . . The feet strike the ground with the same frequency. The loss in velocity occurs because less ground is covered in each stride.'

Any relevance to sprinting backwards must be inferred from Backward Walking: A Simple Reversal of Forward Walking? by D Winter and N Pluck (Journal of Motor Behaviour, 1989). Their biomechanical analyses of the joint and muscle movements of six subjects walking forwards and backwards reached the conclusion that 'backward walking is almost a simple reversal of forward walking'.

So race on, Falstaff, but only against people of your own age.