The psoas muscle and how it can affect your seat

In the last few weeks a large majority of riders that I have been treating have come to see me for low back or pelvic pain. In this group I have found that a major contributor of symptoms has been unilateral (one sided) or bilateral (double sided) psoas muscle tightness.

The psoas is functionally divided into 2 muscles - the psoas major and psoas minor. However the psoas minor is often missing in many individuals and so we will consider it for now as a single muscle. It has its origin at the vertebral bodies and transverse processes of L1-5 and the discs of T12/L1 to L4/5. It crosses over in front of the pelvis to insert onto the lesser trochanter of the femur. In other words, it starts from the lower back, runs through the abdomen, over the pelvic bones to attach into the top of the thigh bone. You have a psoas muscle on each side and these muscles are independent of each other (in much the same way you have 2 hamstring muscles).

 The origin and insertion of the psoas muscle.  Source - Wikipedia

The origin and insertion of the psoas muscle. Source - Wikipedia

The main function of the psoas is to flex the hip, however recent research suggests that it also plays a role in stabilising the spine and also in contributing to spinal movement, particularly flexion and side bending.

Typically issues relating to tightness or shortening of the psoas muscles relate to sitting for extended periods of time. Objectively I commonly see the following signs in my patients with psoas tightness:

  • increased lumbar lordosis, ie increased curve in the lower back
  • shortened stride
  • poor functional squat ability - either weakness or limited range in the hips and pelvis
  • inability to lie flat on the back with the hamstrings fully on the floor and the lower ribcage down
  • limited lumbar spine extension 
                                              Typical riding posture of a rider with a tight psoas muscle.

                                             Typical riding posture of a rider with a tight psoas muscle.

In the saddle these riders tend to sit with their chest thrust forward, their pelvis rotated forwards and their chin jutting out. Typically they grip with their knees and have their lower leg pushed back to compensate for the forward position of their trunk. Try sitting in this position in the saddle. How does your horse go? Chances are their own back hollows in response, the head comes up and they lose all forwards momentum. It's difficult to expect the horse to be round and going forwards from behind when the person sitting on their back is unbalanced, rigid and has all their weight on the front of the saddle.

Physiotherapy treatment includes releases of the psoas and surrounding musculature and soft tissue, along with treatment of commonly related issues including pelvic and spinal alignment, stiffness in the spinal joints, hips and pelvis and muscle imbalances. Dry needling is often an effective technique for releasing tight psoas and the surrounding muscles. An exercise program focusing on spinal and hip mobility, core stability and general spinal and leg strengthening is often prescribed.