4 things you need to know about the iliopsoas muscles
The iliopsoas is a group of three muscles that acts as a hip flexor and can often be a source of dysfunction for the horse. Here are some things to keep in mind about this area.
The iliopsoas is a group of three muscles which acts as a hip flexor.
One of my all-time favourite muscles, both in human and horse, is the iliopsoas. This term actually describes three muscles – the psoas major, psoas minor and iliacus. While there are important differences between them, they are all hip flexors and tend to work as a unit. This newsletter is too short to get into the differences of the individual muscles, so let's just talk about them as a group.
The iliopsoas runs roughly from the lumbar vertebrae to the pelvis and femur. When it actively contracts, it flexes the hip joint and coils the pelvis. It plays a major role in bringing the hind legs further underneath the body, which is an important aspect of collected movement. Iliopsoas dysfunction is incredibly common in horses (and humans too, incidentally). Without getting too technical and boring, here are some major points to remember about the psoas.
The iliopsoas shares its attachment at the lumbar vertebrae with the diaphragm. This means that whatever will affect the psoas, usually affects the diaphragm as well, and vice versa. If your horse is girthy, has breathing issues or long-standing digestive upset, it would be a good idea to check his iliopsoas as well.
Often the iliopsoas muscle is shortened and tight, locking the pelvis in a flexed position. In these horses, exercises like the pelvic tuck are very much contraindicated. Before implementing any exercise programme, consult your bodyworker or your vet.
Some professionals believe that the iliopsoas plays an important role in stringhalt and shivers. While this is not confirmed by solid scientific evidence yet, it is something work taking note of if your horse has either of those issues.
The psoas lies too deep in the body to be worked on directly. But that doesn't mean that we cannot influence it through working on neighbouring muscles and fascia. A good bodyworker will be able to soften this area and restore a better range of motion.
A pelvis stuck in flexion is often an indicator of iliopsoas dysfunction.
Although we can’t access it directly we can influence the iliopsoas indirectly.
In order for the horse to properly make use of his hind end, his iliopsoas muscles have to be working well. If they are not, this will reduce the range of motion of the hind end, the spine and the ribcage. If you suspect your horse might have issues in this area, consult a bodyworker.