Surface strain on the dorsomedial metacarpus of yearling Thoroughbreds at different speeds and gaits on a treadmill

Abstract

Stacked rectangular rosette strain gauges were used to measure surface bone strain on the dorsomedial cortex of the third metacarpal bones in 6 yearling (16 to 19 months old) Thoroughbred horses during exercise on a treadmill. The peak principal compressive and tensile strains, angle of the peak strains and strain rate during loading were calculated and compared with speed and gait. At speeds ranging from 4 to 16.5 m/s there was compression of the dorsomedial cortex of the metacarpus and the magnitude of compression and rate of compression were proportional to the speed of exercise. At the walk (2 m/s) tension was recorded in some strides. The mean maximum compressive strains in the 6 horses..