Body Protectors and Air Jackets Explained
Body Protectors and Air Jackets perform in different ways
The purpose of a traditional body protector is to help prevent injury to joints, bones and internal organs in the event of a riding accident when thrown from a horse or kicked. It does this by absorbing and spreading the forces involved.
To a large extent body protectors are designed to emulate a ridged shell with spinal conformity and have the effect of wrapping around the ribcage. They should be impervious and ideally largely unbending around the circumference of the upper body, backed up by an impact absorbing and dispersing layer to cushion the blow. Too much flexion in the shell would allow blunt point impact to bend and possibly break a bone.
An air jacket is designed to help provide protection by decelerating or slowing down the moment of impact when the rider separates from the horse. Air jackets offer a solution to some types of fall. However to spread impact loads on the rider’s body, a body protector must also be worn because the inflated bladder of an air jacket will not dissipate sufficient energy – instead this is transferred which is why there is a “bounce” and the energy exists until it is used up through transfer. BETA, the FEI and BE insist that if you are wearing an air jacket it must be worn with a body protector to give sufficient impact absorption.
Physics of Impact
When falling from something there is the energy from gravity accelerating the person’s weight (mass) plus the energy given by the thing they fell off (bike, horse etc). Most riders are sitting at over 1.4 metres (4’8”) above the ground. That is a long way to fall, even when the horse is stationary. Once on the ground there is the added danger of being kicked or trampled – an average horse weighs 1000-1200 lbs, (455 – 545 kg), so the risk to the rider is significant.
Newton’s third law of motion states: “Every action has an equal and opposite reaction” i.e. push a ball and it rolls away, the more energy put into the push the further the ball goes. When landing, this energy has to go somewhere and often the energy goes into the rider’s body. Therefore the choice of safety garment must be shock absorbing so that the body inside is protected.
In a horse riding environment impact types would be:
- Flat impact on ground with no hard lumps
- Blunt but point loaded impact i.e. a rock, tree root, fence post or rail
- Sharp penetrative
I would say that the first two and a combination of both were most likely. If when falling from a horse we hit for example a tree root or fence, the energy is transferred into a small area causing greater damage than if we fall onto flat ground. Therefore it is vital that the rider chooses the best shock absorbing and energy dispersing materials as their primary layer of protection (it is all about lessening the transfer of energy to the body). Body protector foams for use in the equestrian sector are designed to pass stringent impact tests.
All body protectors carrying the EN: 13158 or BETA marked labels have been tested to one of 3 levels and this denotes that at each level the body protector is capable of absorbing and spreading a given amount of impact. Protectors meeting BETA Level 3 should provide a level of protection that is considered appropriate for normal horse riding, competitions and for working with horses. These certified body protectors also have specific dimensional and space requirements so that sufficient torso areas are protected.
Air Jackets are not body protectors. Whatever the benefits of wearing these items, currently none of them meet the relevant European CE standard for body protectors for equestrian use. To pass the standard protectors must be independently tested by a European-approved laboratory, using impact performance test methods to simulate impact due to falls and kicks from horses.
My thanks to the Impact Engineer and Aeronautical Engineer who helped me get the physics right.
Contributor: Wendy Smyth, Founder Kan Teq Body Protection
Wendy, herself a rider, has a background in the fashion industry and has been involved in researching bullet proof materials. In the search for a more flexible and stronger material for body protectors, Wendy looked at other high risk sports and identified Planet Knox who have been the market leaders of motorcycle body protection since 1981. Wendy had worked as a design consultant for several large military bullet proof vest manufacturing companies to improve body armour and believed that this experience combined with her participation in equine sports gave her the knowledge to develop the KAN to the highest safety and comfort standard possible. Visit the Kan Teq website HERE