How do shoes affect foot skeleton stresses in racehorses? An international research team is tackling the question in a project that is likely to benefit the racing industry and protect horses from injury.
Horse hooves have the ability to naturally deform during locomotion and dissipate locomotor stresses, yet farriery approaches are used to increase performance and protect hooves from wear, the study team, writing in the journal PeerJ, noted.
“Previous studies have assessed the effect of different shoe designs on locomotor performance; however, no biomechanical study has hitherto measured the effect of horseshoes on the stresses of the foot skeleton in vivo [in the living organism].’
Musculoskeletal injury is one of the main animal welfare concerns in the racing industry, notes University of Queensland School of Biomedical Sciences research team leader Dr Olga Panagiotopoulou.
The researchers from the University of Queensland, the Royal Veterinary College in Britain, and Brown University in the United States are using a new approach that combines three-dimensional x-ray imaging technology with computer simulations and models to show the forces exerted on bones.
“This novel combination has enabled us to study the effect of a stainless steel horseshoe on skeletal stresses within the forefoot in a live racehorse,”” she explains. “This is the first time this combination of techniques has been used in large live animals such as horses.
“Future research using more animals will enhance our understanding of what regions of the horses’ feet are most at risk of damage.”
The method was used successfully in a preliminary case study at the Royal Veterinary College in London.
Royal Veterinary College vertebrate biomechanics and evolutionary anatomy researcher Professor John Hutchinson says further research is necessary.
“We need to undertake further studies with more horses moving at faster speeds and gaits and with a similar focus on the hind feet.”
The research involved walking a thoroughbred between three-dimensional x-ray machines, an imaging technique developed by Professor Stephen Gatesy and colleagues at Brown University and used previously to view bone interaction in small animals such as fish and birds.
Panagiotopoulou used film industry animation techniques to transform the radiographic data into a life-size three-dimensional model.
“By combining the 3D model with other research data we were able to measure the force the horse’s foot bones generated when they hit the ground and develop comprehensive simulations,” she says.
“We believe this work could pave the way for new directions in research which will minimise foot injuries and improve animal health and welfare.”
Their preliminary findings pointed to increases in some stresses on the forefoot phalanges in the shod condition at mid-stance, consistent with the tentative conclusion that a steel shoe might increase mechanical loading.
“However, because of our limited sample size none of these apparent differences have been tested for statistical significance,” the study team wrote in their paper.
“Our preliminary study illustrates how the shoe may influence the dynamics and mechanics of a thoroughbred horse’s forefoot during slow walking, but more research is needed to quantify the effect of the shoe on the equine forefoot during the whole stance phase, at faster speeds/gaits and with more individuals as well as with a similar focus on the hind feet.”
They anticipated that their preliminary analysis and new approach would pave the way for new directions in research on the form/function relationship of the equine foot, with the ultimate goal to minimise foot injuries and improve animal health and welfare.
“Despite our study’s restriction to measuring a few steps of one individual and assuming a static posture and massless foot segments, it is an important example of the integration of 3D biomechanical methods and their application to fundamental problems in equine locomotion, care and welfare.”
Panagiotopoulou O, Rankin JW, Gatesy SM, Hutchinson JR. (2016) A preliminary case study of the effect of shoe-wearing on the biomechanics of a horse’s foot. PeerJ 4:e2164 https://doi.org/10.7717/peerj.2164
The research techniques shown in this video allowed researchers to zoom into the skin and hoof and measure the motion of the horse’s foot skeleton, which is not possible by other methods.