Isn’t it interesting when the universe seems to unfold in cycles or themes? This spring my 28-year-old sound school horse suffered a bodywork-related injury – a strained iliopsoas complex. That’s more than a little bit ironic because over the past few years I have focused on teaching riders to access and connect to their horses through their core muscles and the psoas figures quite prominently in this work.

By coincidence, an equine journalist I know had been telling me about a British bodyworker who has written an interesting take on the importance of the equine psoas. The Equine Psoas Manual: Reacquainting his body and soul … by Joanne A. Greenfield is a dense little book that offers up myriad fascinating nuggets of wisdom in just 82 pages.

I have been studying and working with the psoas pretty consistently for the past six years, and I know a number of interesting things about this unusual muscle complex that originates from the lower ribs and transverse processes (sides) of the lower thoracic and all the lumbar vertebrae, spans the ventral side of the pelvis and inserts into the medial side (inside) of the femur. That’s right, the psoas connects the human body from top to bottom and back to front. In your horse, the psoas is important in drawing the hind legs forward under the barrel and in movements that require the horse to engage his hindquarters or “sit.”

This muscle group is maybe the most interesting in the entire body because of the seemingly contradictory functions it performs. Writes Greenfield, “This muscle group is hidden deep in the horse’s body and is not very often mentioned, yet it serves great purpose in the horse’s athletic ability as well as his ability to rest.”

From my colleague who is a former meat scientist, I know that the psoas is the most tender muscle in the body, aptly known as the tenderloin in meat animals, the place you get those luscious filet mignon steaks. From my yoga teacher, I know that in humans (especially those who sit a lot) the most common condition of the psoas is weak and tight; therefore, it is a muscle that must be induced to release, not stretched. From my massage therapists I know the psoas is a storehouse for emotional baggage, so that providing physical relief often induces an emotive release.

All of this has informed my work with horses and riders, but Greenfield’s book adds several new dimensions to my understanding of the importance of this exceptional muscle. Many of her observations seem at odds with the conventional wisdom of conditioning and training.

Take for example this insight, presented in a chapter about the rider’s psoas but surely equally applicable to the horse as well:

Conscious ‘holding’ of muscles prevents them from doing their job instinctually, which is to respond to movement stimulus and allow the body to yield and absorb movement where necessary. Strength is not something that needs to be built into a muscle rather something that the body has naturally when it is able to work as a whole unit instinctually.

	Before and after views of the topline of a horse with a strained psoas complex.

Greenfield sources alignment problems in the bodies of domestic horses as an interruption in the cycling of flight energy through the body. She postulates that when a horse is prevented from expressing “the full extent of his flight energy” by spatial constraints such as fences or by a rider’s constricting movements, excess “nervous flight energy” can accumulate and cause tension in the horse’s body. She goes on to suggest that discharging this excess energy – finding a way to “unravel the body back to neutral” – is necessary for the horse’s physical and emotional wellbeing.

This section of the book offers up one of my favorite lines: “What the walls and fences trap, the hands can set free …” And the author goes on in the book to explain just how this can come about when she writes about the joints and muscles in the neck and how their function complements the work of the psoas complex.

Greenfield discusses the important counter-relationship between the head and neck and the hindquarters in the horse’s balance and freedom of movement, suggesting a counter-balance situation that might cause riders to reconsider how they work with green or unfit horses on circles.

Switching her focus to the rider, the author offers up what I found to be a truly fascinating connection between riders’ physical disfunctions and their horses’ bodies. Put simply, she suggests that while riding might give some people relief from pain they feel on the ground, this does not happen without a cost to the horse. Anyone who finds his or her riding partnerships chronically stuck at one level or who repeatedly experiences the same training challenges might find some answers in this chapter.

I believe every thoughtful rider is likely to find something in this book to engage and enlighten, to exercise his or her critical thinking skills and spark interesting conversations with other riders. There are many good authors writing on anatomy and bodywork and any number of books a student of riding biomechanics can read for scattered tidbits of useful information. But I found The Equine Psoas Manual so densely packed with unique information and insights that I read very slowly, sometimes taking hours or even days to absorb and contemplate the information contained in a single paragraph. Stacey Kollman

For more great reads, check out the Desert Horse Bookshelf.

© 2011 Desert Horse Services/Stacey Kollman