Body, Health & Fitness

Welcome to this course!  I am sure if you are involved in canine sports, or active in dogs, you have directly or indirectly had some exposure to the iliopsoas.  It has definitely been a 'hot topic' in the past decade in the world of dogs.  This is YOUR course to learn more about the iliopsoas, how to prevent problems, how to address them, and how to make sure the problems do not come back again!

Definition and location of muscle –

This is one of the most complicated muscles in the dogs’ body and one that is being talked about a great deal lately!  It deserves a lot of attention due to its complexity, demand, action, and location.  Let’s start with the basics.  It is located in the hindlimb. It originates in the lumbar spine or the lower back, and inserts in the femur or upper thigh.  We will get more specific in a minute, but I would like you to think about the origin and insertion – starts in the lower back and inserts in the femur or thigh bone.  The muscle works on two areas – the lower back and the hip.  It has two big jobs – to extend the lumbar spine and flex the hip.  In other words, it is going to straighten the spine and bend the hip. (Any time the joint angle is increased, it is extension.  When the joint angle is decreased, it is flexion.)

Examples of extension include when a do jumps on a couch, takes of to go over a jump, jumps off a dock or a boat, or jumps off of a deck onto the grass to chase a squirrel.  Examples of hip flexion would be when the dog goes up a flight of stairs and brings the leg up, moving from a stand to a sit, and landing after a jump.  And these are just a few examples.  I would like you to start thinking about how active the hip and lower back is during normal movements.  The iliopsoas is one of the most complicated muscles in the hindlimb of the dog.  The piriformis is another ‘up and coming’ muscle and could be another problem that is not recognized enough in canine sports medicine.

In the diagrams and illustrations below, you can see the muscle pointed out in different views. In the first one the iliopsoas is the right muscle coming down near the rear.  As you look at this diagram, start to appreciate the beginning of the muscle on the spine, and insertion of it on the rear or hip region. In the second photo, a different view is provided of the muscle. Again, please appreciate the depth of the muscle.  The diagram is not showing everything else in the body that lies beneath!  In the third photo, we can see a view from the underneath, looking up.  So imagine you were lying on the floor looking up at your dog's belly (and I guess parts too!).  And in the fourth diagram, you can see the thickness and depth of the muscle.  The iliacus is coming off the pelvic area - or the crests on the each side.  And the psoas is coming off parts of the lumbar vertebrae.  We are going to revisit this again in a few minutes!

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The iliopsoas is actually comprised of two muscles coming together.  The iliacus and the  psoas major muscle. Each of these muscles comes off as individual parts and combine into one to insert or attach into what is called the lesser trochanter of the femur.  At the attachment, it is a very thick muscle. In the cow, it is the tenderloin or filet mignon.  (Sorry for those vegetarians out there!). But it is a thick, muscular component.  When injured, you can imagine how tender it can become.  This muscle attaches the spine to the legs!  It helps support the spine, advance the leg forward, as well as helps support internal organs. It is a very important muscle and does deserve a lot of attention! In people, problems with the iliopsoas have been linked to pain, lower back pain, spondylosis, spondylosisthesis, knee pain, hip pain, sacral pain, abdominal issues, stress, anxiety, breathing irregularities, bladder issues, and altered immune system. Because the dog is a quadraped, as opposed to the human biped, we do not have the exact same thing, however, it is interesting to think about.  The iliopsoas is intimately related to many internal organs and it acts to protect these organs.

                i.         Diagrams in still and in action - in the photos below, the following motions are going on:

1) Hip flexion as the dog is jumping up

2) Hip extension with the front feet on the larger Inifinity and the back feet on the smaller Infinity

3) Hip flexion while sitting on the Disk

4) Hip flexion while stepping off the step

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              ii.         Lumbar component – the lumbar spine is comprised of seven vertebrae.  In people, the lumbar spine has five vertebrae.  So, the dog’s spine is longer than a persons’. The psoas major starts on the transverse processes of L2 and L3, and the bodies of L3 through L7.  In other words, this part of the muscle is coming off the sides of the upper lumbar and the middle part of the rest of them.  All of the lumbar vertebrae are involved except the first one!  This will be such an important fact to think about later on.  The iliacus muscle originates on the medial or inside surface of the wing and the ilium.  So this portion is coming from the inside of the pelvis.  Even if this is all ‘Greek’ to you, I would like you to understand that a huge component of the iliopsoas muscle is the spine and pelvis.  When preventing and addressing an issue with the iliopsoas, it is imperative to factor in the strength, motion and stability of this region.  The active dog will need good core control and part of the recovery process from an iliopsoas injury will be to address the lumbar and pelvic component.  Core control will be paramount in addressing these problems.  Throughout this course, I will continuously go back to the origin of the muscle and focus on core strength.  If that component is missing, the dog will not be successful in preventing or coming back completely from an iliopsoas problem.  I know the diagram is up above too - but look at it again after what you just read and absorbed.  Pretty amazing, huh?

             iii.         Hip component – after the iliacus and psoas major leave their respective origins, they join and form a thick band.  This band inserts into the lesser trochanter of the femur or upper leg.

             iv.         How to palpate – one of the more difficult things to do is actually palpate the iliopsoas.  For the meat eaters in the group, I already have you thinking about how thick the muscle is – but how tender.  These are three videos of palpating the iliopsoas.  The setter has nice range of motion and no pain at all with the motion.  Savannah, the plot hound mix, also is not painful.  Hendricks, the black cocker spaniel, offers another view.

Bogart, the Clumber Spaniel, does have a tight and painful iliopsoas, secondarty to a dysplastic right hip. You can see the painful reaction.  

Photos below are more examples of iliopsoas palpation:

1.  My thumb is on the iliac crest or the part of the pelvic area.  My middle finger is on the iliopsoas while the index finger is resting lightly.  My ring finger is also resting lightly.

2.  In this photo, you can see the right leg is more forward than the left leg.  The tight right iliopsoas is pulling the right hindlimb forward.

3. My right thumb is on top of the iliac crest.  The right side is more forward due to the tight pull on the right iliopsoas.

4.  The level is demonstrating the right forward leg on the Aussie. The tight right iliopsoas is pulling the right leg forward. 

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In the series of photos below, the dog is presenting with a left iliopsoas injury.  The fifth photo is demonstrating a left hip external rotation.  On the sixth photo, the area is being palpated for iliopsoas pain. The seventh photo is palpating the ischial tuberosity, or the butt bone.  The left ischial tuberosity is part of the iliac crest and is connected to the 8th photo.  In the 8th photo, the left sacral sulcus is a little bit more forward than the right.  My thumbs are on the area.  The diagram next to th 8th photo is pointing out the landmarks.  My thumbs are on the iliac spine (cranial dorsal).  The dog in photo 8 has more of a forward left iliac spine due to the injury of the left iliopsoas. 

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