Training mature racehorses produces a decrease in the protraction (extension) time of the forelimb and might reduce the risk of training-induced injuries, according to Marta Ferrari, DrMedVet, PhD, MRCVS, of Park Veterinary Centre in Watford, UK, and colleagues at London's Royal Veterinary College in a new study.

The researchers aimed to investigate the effect of training on stride parameters. For one week, they measured the speed, stride frequency, stance time (the period during a stride when two legs are on the ground), and protraction time of eight racing Thoroughbreds six months into training.

"In our study, a significant average decrease in protraction time and a corresponding significant increase in stride frequency were found after training," she said. "The decrease in protraction time observed in our study could be influenced by muscle development. After training, a higher muscle power could result in a more efficient and quicker protraction of the leg, whereas stance time could be more related to leg stiffness and the energy storing properties of passive tendons, which may not be affected by training and fitness level."

The investigators found no significant differences in stance time before and after training. Stance duration, once acquired after the first period of a horse's training, tends to stay constant