Horse helmets and load cells: testing strength from side impact

Horse riding helmets are designed to protect the horse rider if they fall off their mount, whether in racing, the show ring or on a trial course. However, the situation can be far worse if the horse falls too, and lands on their rider.

A study published in Applied Sciences used load cells to test the strength of riding helmets when crushed from the side, as in the situation when a horse might fall onto the rider’s head. The team from (location) created a head form the size of the average male head filled with sensor, put it inside a standard 57cm jockey-style helmet and recreated the conditions of falls at various angles.

The head form began as a CAD model using the external geometry of a EN960:2006 standard, and the fit of a size J riding helmet. The head form was then 3D printed, before being fitted with a uniaxial load cell rated to 70 kN. Data acquired via a single channel laboratory amplifier was then filtered to ISO 6487.

 

Two horse cadavers were then dropped onto the head form with and without from a height of 1 metre, equivalent to an impact velocity of 4.43 metres per second. The researchers at the University of Dublin were particularly interested in the impact from four points on the horse’s rear quarter, including the lumbosacral and sacral vertebrae. Their findings showed that whilst the helmet significantly reduced the forces to the side of the head form, the forces were great enough that a human skull would be fractured in all tests.

 

Near infrared (NIR) spectroscopy on equine knee cartilage

Horses are prone to knee problems just as we are, including osteoarthritis. A team from the University of Eastern Finland wanted to evaluate “the condition, mechanical properties, structure, and composition of equine articular cartilage” and create a dataset as relevant to humans as horses. Cartilage was obtained from equine fetlock joints from an abattoir, mounted in a custom-made sample holder and bathed in solution to simulate real-life conditions.

“Cartilage bio-mechanical properties were determined through indentation testing with a custom material tester using plane-ended cylindrical indenters (d = 0.53 mm & 0.51 mm). The material tester consisted of a load cell (5 mN resolution) and an actuator with a displacement resolution of 0.1 µm.”

 

Load cells and saddle girths

Load cells have also helped researchers investigate other aspects of horse riding, including the optimum girth tension. The girth is the strap that holds a saddle on a horse’s Back. Too loose, and the saddle can swing around and throw the rider. Too tight, and the horse can be in discomfort and quite literally, put of its stride. Usually, the tightness of the girth is judged by the rider according to their own preference and the activity. Research by Molton College in Northampton used load cells to measure the tension in girth straps to see how it affected the horse’s stride length and overall speed.

According to the College’s aptly named On the Hoof newsletter:

“A custom designed S-type tension load cell was used to continuously monitor the tension in the girth during the period under test. The load cell was mounted almost vertically alongside the chest of the horse where unwanted torsional effects on the load cell would be at their minimum, it was fitted to the strap via rod-end bearings and a cam buckle so that minute changes to the girth tension could be made. This was connected to a T24 telemetry module, located in a pouch on top of the saddle which transmitted the force reading wirelessly to a telemetry base station located nearby.” 

 

Keeping horses healthy with load cells.

Back in 2018, we explored the ways load cells are helping horses keep healthy, including hoof health and tacking equine obesity.

 

Racing back to research

If you have an innovative research project requiring specialist force measurement, we can help. We relish working with researchers and university departments on custom load cell setups to help capture data in unusual ways or in challenging environments. Just call us to discuss your requirements.