Iliopsoas strain in dogs
Iliopsoas is the name for the iliacus muscle and psoas major muscles together. Iliacus arises from the wing of illium of the pelvis, and the psoas major is a sublumbar muscle, originating from below the lumbar verterbra 2 - 7. Together both these muscles insert onto the inside of the femur in the back leg, just below the hip joint and are known as the illiopsoas group, or more commonly psoas. The psoas act to flex the hip and the lumbar spine.
Psoas strain is a very common, and frequently under-diagnosed condition in dogs. The psoas is a deep muscle and it is often forgotten about. It is sometimes confused as hip pain as when a dogs hip is extended to test the hips the psoas will also be stretched, and a tight psoas is very painful. Sometimes a dogs posture can give away the condition - they will be rounded through the lumbar spine and pelvis.
Psoas strain is often present with many other musculoskeletal problems. It is often seen concurrently with spinal, pelvic, hip and stifle complaints. It can also occur with abdominal discomfort such as inflammatory bowel disease.
Running through the psoas group are 3 different nerves which can be affected by a tight and painful psoas. The femoral nerve is one of these and innervates the quadriceps group, which act to extend the stifle. The obturator nerve is another and innervates the adductors of the hindlegs, or muscles that act to draw the hindlimb in closer to the centre of the body. These adductor muscles are on the inside of the hindleg. Finally the genitofemoral nerve that supplies the skin of the groin region also passes through the psoas. So psoas strain can create dysfunction in multiple areas of the hindlimbs.
To treat a tight psoas there are a few different methods that I use. Osteopathic counterstrain is very effective. It involves bringing the two ends of the muscle closer together to relax and release the muscle. The psoas can also be treated using acupuncture or myofascial kinetic line treatments. Addressing psoas problems also involves treating other underlying concurrent issues with the musculoskeletal system. I don't usually use stretching to treat a tight psoas as it can be very painful, however I may give owners some stretching homework as aftercare to maintain proper psoas function following treatment.