Any dressage horse capable of performing a top-notch piaffe is a skilled animal indeed, the findings of fresh research suggest.
The piaffe is a difficult balancing feat in a specific posture, equine researchers Hilary Clayton and Sarah Jane Hobbs noted in the journal Animals.
It is acknowledged as one of the hardest movements performed by dressage horses, in which the animal raises and lowers alternating diagonal limb pairs while remaining in place.
For a horse, it is an artificial movement that requires balancing skills, and is required to be performed in place only at the highest levels of competition.
Clayton and Hobbs, in their just-published paper, set out to explore the ground reaction forces (GRFs) of dressage horses performing the piaffe.
They said knowledge of the unique stresses on the horse’s limbs and body during the performance of the piaffe is needed to understand the mechanics of the movement and the implications for injury.
The researchers used force plates to measure the GRFs in the vertical, longitudinal and transverse directions in seven highly trained horses performing the piaffe.
The recruited horses comprised three Dutch warmbloods and four Lusitanos. All had competed at grand prix level and one of the Dutch warmbloods was a multiple Olympic medalist.
The results showed that the hindlimbs carried relatively more weight in the piaffe than in trot or passage, though the peak vertical GRF was significantly higher in the forelimbs.
The forces acting in the horizontal plane showed considerable variability from step-to-step within individual horses. “This,” they said, “was thought to represent the difficulty of maintaining balance when the horse stands on one diagonal pair of limbs.”
Peak vertical GRF was significantly higher in forelimbs than in the hindlimbs.
Discussing their findings, Clayton and Hobbs said that, in biomechanical terms, the horse must balance on a diagonal pair of limbs while raising the other diagonal pair in a controlled manner and briefly holding the swing phase limbs in their most elevated position.
“This implies that the horse must be stable while balancing on a diagonal pair of limbs.
“Since piaffe is performed in place, it has a greater reliance on static equilibrium than passage, with adjustment of GRFs likely to play a major role in maintaining balance.
“Perhaps the most notable feature of the GRFs in the piaffe is the variability, not only between horses, but also from step-to-step within individual horses.”
This most likely represents the difficulty in staying balanced on a diagonal pair of limbs, the said.
The results showed just how skilled the horses were in balancing the forces required to stay fixed to one spot. In most of the steps analysed, they did just that. On the occasion step when they didn’t, the horses took a small step forward or a small step back.
It is clear, they said, that high-level dressage horses require great strength and finely tuned neuromotor control. “This is acquired and further developed through a prolonged program of dressage training.”
Clayton is with Large Animal Clinical Sciences at Michigan State University, and Hobbs is with the School of Sport and Health Sciences at the University of Central Lancashire in England.
Clayton, H.M.; Hobbs, S.J. Ground Reaction Forces of Dressage Horses Performing the Piaffe. Animals 2021, 11, 436. https://doi.org/10.3390/ani11020436