The January 2013 version (with functional links and videos) of the below blog post can now be found at:
I've been meaning to write this post for quite some time so finally here it is. I am sure there are some great authorities out there who could explain it all much better and I am by no means an expert. This is just a result of some experiences and lots of digging in the widely available sources.
The first time I was told about psoas/iliopsoas muscles was about 16 years ago while training long distance running as a teenager. The psoas muscles can get really tight in runners so specifically designed stretches were part of our every day training. I had never really thought about them since then until many years later I had a chance to train with a dressage trainer and rider. She was trained by a Centred Riding instructor while working with horses in Germany. It was my first year in the UK and I could barely understand simple words spoken with British accent not to even mention medical vocabulary so our sessions were challenging to say the least ;) What I learned from her though completely changed my riding and the way I teach now. I am still learning how to pass this knowledge on to my riders and how to use it better myself.
This post is about the Psoas muscles, the muscles that MAKE the rider...
What are Psoas muscles?
"They are located deep in the abdomen, on both sides of the lower spinal vertebrae. We do not think of the psoas muscles because the functions they perform are done in conjunction with one or more of the surface muscles. This is probably the reason the riding world does not look further than the surface muscles at the front and back of the body when determining how riders stabilize themselves on their horses. Out of sight, out of mind.
The psoas muscles are the bridges between the upper body and the legs. They are the only muscles that directly link the spine to the legs. The psoas attach directly from the lower spine to the top of the inner thighs at the lesser trochanter of the femur. They do not attach directly to the pelvis, but influence it through their connection to the iliacus muscles, which are attached to the walls of the inner pelvis.
The psoas muscles flex your thighs at the hip, enabling you to raise your knees, thus lifting your feet off the ground. Since the tendons of the lower part of the iliopsoas attach to the inner thighs,when flexed, they also tone the adductor muscles located on the inside of your thighs."
[Source: http://www.zenandthehorse.com/psoas.asp ]
How and What For do Riders Use the Psoas
"I began offering bodywork sessions at the local riding center. I realigned and balanced a rider’s body using Zen Bodytherapy® alignment techniques and Zen Triggerpoint Anatomy® work. During these sessions, I asked each person to flatten his or her back against my table. Most of the riders who did this tightened their abdominal muscles when bringing the front of their pelvises up in order to flatten their backs.In the process of working with about twenty riders, two of them did something completely different from the rest. Both were able to flatten their backs while their abdominal muscles fell back and softened. This was something I had seen before, but only in bodies that had completed the series of Zen Bodytherapy® sessions. It indicated to me that these riders were using their psoas (used for both singular and plural) muscles to flatten their lower backs. I asked both riders where they had learned to do this, and both said it had been while riding bucking horses when they were young. I considered these riders to be expert horsemen and both were using their psoas muscles to adjust the position of their lower backs!
I later had the opportunity to ask an expert rider if he used his psoas muscles when riding. Although he had not previously heard of the psoas, when I showed him a model of the spine and the psoas muscles, he said they were in fact the muscles he used. He went on to explain he used these muscles to distribute his weight over the horse’s back and this was important in enabling his horses to jump correctly. This confirmed my theory that accomplished riders were using their psoas muscles to stabilize themselves on their horses."
Working the Psoas/Iliopsoas
One of the very simple yet very effective exercises I was shown is done while sitting in the saddle. You need an assistant to do this without too much muscle strain. I will describe the exercise fully in the post below (direct link to it: Working The Psoas Today).
For now have a look at this video. Not only does it explain well about the function of the Psoas Muscles but also shows some exercises that are similar to what I was taught when I was running and which are very useful for riders:
More links of interest: