Fractures sustained by racehorses in Japan during flat racing with special reference to track condition and racing time

We found significant effects of track condition on injury incidence. The incidence of fractures decreased as track conditions on turf became softer and increased as track conditions on dirt became muddier. Because of the general trend for the incidence of fractures to vary with track condition, we examined the relationship between track conditions and racing times for winning horses in 4117 races and for 50,564 overall runners for the period 1990-1994 on two tracks. For turf courses, racing times became longer as track conditions became softer. In contrast, for dirt courses, racing time tended to become shorter in muddier conditions. The variation in the incidence of fracture with track condition might be due to the corresponding difference in racing time.