There has been a lot of discussion among the eventing community about how to prevent rotational falls — a fall where the horse hits a fence with its front legs or chest and its body somersaults over the fence with the fence acting as a pivot point. In a rotational fall, the rider usually is thrown out of the saddle and goes over the jump before the horse. In a worst case scenario, the horse can land on the rider.

Until recently, it wasn’t clear to me what a rotational fall involved. It’s not that easy to find photos but I have found an example int the YouTube video below. The fall shown at 1:07 in the sequence is clearly a rotational fall. I believe that fall at 1:55 is as well. I understand that Darren Chiaccia’s fall was shown as part of an interview with wbz in New York state, but I’ve not been able to access the footage.

An example of a rotational fall is on this YouTube video, at 1:07 in the sequence; there’s another fall at 1:55 that also looks like a rotational fall.

There is also an excellent sequence that was shot by photographer J.C. Dill. Her work is copyrighted, so I will not post them here, but there is a link to her portfolio on this thread on the Chronicle of the Horse. The horse and rider in this series were not injured and the photos are amazing.

There have been several high profile rotational falls in the past few months among high level riders, Darren Chiacchia being perhaps the most well known. After his horse suffered a rotational fall in March, Chiacchia was in a coma and ended up with a traumatic brain injury, broken ribs and a collapsed lung.

But the debate started long before that. Back in 2001/2002 the British Horse Trials Association studied all incidents involving horse and rider during that eventing season. The Transport Research Laboratory (TRL), the UK’s center for research and advice on all methods relating to transportation including crash testing, got involved and analyzed film of 100 jumping accidents. TRL found what caused most fatalities was the somersaulting of the horse over the fence and onto the rider who was either still in the saddle or lying on the landing side of the fence unable to avoid the falling horse.

Rotational falls occur when a horse hits an upright, solid fence between his knees and his chest. Horses that hit below the knees typically were able to scramble over the fence, but when a horse moving at speed hit a jump with his chest the rotational fall was inevitable.

Crash testing by the TRL showed that  when a horse’s front legs were pushed backwards he turned from a small horizontal force sliding over the fence to a vertical downward force. If the jump didn’t collapse the horse would somersault causing a crushing injury to the rider. If the top rail was able to collapse when the

horse hit it from the knees up, he would fall straight down instead of flip. As a result, the TRL designed a breakaway device that wouldn’t collapse only collapse if the critical weight position was reached. It is called a frangible pin. The image to the right shows a jump constructed by Willis Jumps, cross country course builders to Badminton, Gatcombe Park, the Atlanta Olympics and many other events throughout the UK and the world.

Unfortunately, the frangible pin has not yet been widely adopted yet in the US. Cost is an issue (approximately $70 per fence) and the pins were not mandated for course design because they were not yet widely available. There is renewed interest now.

Results from testing in the UK were positive. During the 2002 eventing season, there were two instances where frangible pins were broken and, on both occasions, neither horse nor rider was seriously injured.

The first instance occurred Weston Park where a horse tried to jump the first rail of a rail-ditch-rail combination from a standstill. Momentum carried the horse over the fence to the critical position of downward pressure on the rail. The pin sheared at the point when downward pressure reached the pre-determined maximum. The rider was thrown free; horse stayed on the take-off side of the fence. Neither horse nor rider were injured and the fence was repaired in minutes.

The second break was at Boekolo CCI***; a tired horse failed to make the back rail of an oxer. Both pins broke and both horse and rider escaped unharmed from an incident that eye-witness accounts suggested would have resulted in significant injury has the pins not been in use.

Collapse of a frangible fence is 70 penalties and a mandatory withdrawal.

Let us hope that the current focus on safety translates to the use of course building techniques that help build safer fences. It seems that the frangible pin is one such tool that could save the lives of both horses and riders.