The position of today's' race jockeys - seen by many as uncomfortable - has sound scientific foundations according to new research from the Royal Veterinary College. It shows that the crouched posture adopted by the jockey frees the horse from having to lift the jockey body weight through each of its strides - thus resulting in enhanced race-time performances.

Until the end of the 19th century, all jockeys assumed a pose on the horse much like that of dressage riders: back straight, head up, seat planted firmly in place. The posture provided plenty of speed and control, and, significantly did not require the riders to support their own body weight - a real consideration over a long race.

That's the way it was in the UK, at least. In the US which always had a wilder frontier relationship with its horses and merely borrowed the sport from the Brits anyway - the rules were looser. It was the Americans of this time that wondered what would happen if they did a little work on their own, standing up in the stirrups, bending forward and surfing the motion of the horse as it galloped.

This new crouched, rather than seated posture that jockeys adopted around the 1900s led to improvements of 5-7% in major horserace times and records. Analysis of winning times for the Epsom Derby stakes from 1845 to present day, for example, shows a substantial decrease in the ten-year period from about 1900.

The question was, how? Simply knowing that the pose works is not the same as knowing why it works - at least, not in the detail a physicist would like. The research team that set out to find some answers consisted of Dr Pfau, Dr Spence, Sandra Starke Dr Ferrari and Prof Wilson.

Their research showed that it would be difficult or impossible for jockeys to isolate themselves from the movement of the mount were they seated or adopting an upright, straight-legged posture.
In contrast, the posture used by today means that the horse supports the jockey's weight, but does not have to move the jockey through each cyclical stride path. In physics, however, nothing comes for free, and as the horses workload goes down, the jockey's goes up. They have also been shown to have near maximum heart rates during racing.

A jockey represents about 13 per cent (about 60kg) of a horse's body mass (about 450kg). The research showed that using conventionally-seated riders and sandbags led to an increase in mechanical and metabolic cost in the animal that was proportionate to the load. The cost of load-carrying is reduced when the jockey and the horse are coupled "elastically" - as they are when the crouched posture is adopted - rather than tightly.

It was surmised that a jockey in the crouched position uncouples himself from the horse by moving relative to his mount. Interestingly, it was also found that, in adjusting his position, the jockey slightly over-compensates for the horse's motion. So, the fluctuations in the displacement and velocity of the combined horse and jockey may be slightly smaller than those of the horse alone. It could be said that the jockey is 'driving' the horse."

The researchers said that the crouched style could also reduce aerodynamic drag, but their calculations indicated this would have accounted for just 2% of the 5-7% improvement in racing times.