In the human, the psoas muscles lie deep inside our body, basically behind our internal organs (stomach, intestines etc) and in front of our spine. The psoas (there are two, one on the left and one on the right) originate along the sides of the vertebral bodies of the 12th thoracic vertebrae and extend down to the 5th lumbar vertebrae, and along the sides of the intervertebral spinal discs. They then travel down deep in the abdomen to attach below the lesser trochanter of the femur (long thigh bone) which is located towards the inner thigh region. The psoas is joined at the hip (literally), by the iliacus, which travels from the hip to the thigh. Together, the psoas and iliacus make up the iliopsoas–the body’s most powerful hip flexor.
So why should we care about this hard-to-find muscle with a funny name? Mainly, because it is the psoas that enables you to move your legs and hips independently. Every time you lift your knee, the psoas contracts. When your leg swings back, the psoas lengthens. You use your psoas to tuck your pelvis under. The psoas also promotes good posture. In conjunction with other muscles, such as your abdominals, obliques, and lower back muscles–the psoas helps stabilize your midsection and pelvis. Every time you stand, walk, or ride, you’re engaging the psoas. If the muscle is compromised, either by injury or tightness, your riding inevitably suffers.
Most yoga and pilates students are aware that the psoas is a central player, even if the muscle’s deeper function and design seem a mystery. As the primary connector between the torso and the leg, the psoas is unbelievably important to the rider.
A tight psoas can cause serious postural problems: it pulls the low back vertebrae forward and down toward the femur, often resulting in lordosis (overarching of the lumbar spine), which is a common cause of low back pain and stiffness; it can also contribute to arthritis in the lumbar facet joints. This translates into a rider posture with a hollowed lower back – the pelvis is tipped forward, with the seat bones pointing towards the rear of the horse. The knee is automatically held away from the horse due to the shortening of this muscle, and the toes are held in a turned-out position.
On the other hand, a weak and overstretched psoas can contribute to a common postural problem in which the pelvis is pushed forward of the chest and knees. This misalignment is characterized by tight hamstrings, frequently seen in riders as difficulty in getting your heels down, and a chair seat.
During standing or sitting, both psoas muscles are continuously active, in order to assist with the positioning of the hip, pelvis and lower back. The same thing occurs when we sit on a horse, we need our psoas to maintain a neutral curvature of the spine and to allow our legs to drape around the horse’s sides, providing a knee and foot forward position, along with much more contact of the upper thigh due to it’s flattened orientation against the horse.
When we walk our psoas is active during the initial swing part of the stride while the opposite psoas muscle is considered most active during the mid-stance (weight bearing) portion of the gait. When riding we need our psoas to lengthen and contract sufficiently to allow our pelvis to follow our horse’s movement.
There is a significant relationship between the human and the horse’s spine and pelvis. It is imperative for the rider to be able to open their low back, stretch and activate their psoas muscles in order to encourage more fluid motion of their spine, pelvis and hip. If we are unable to achieve this in our own body, we cannot ask our horse to engage its’ psoas which it needs to do during more engaged manoeuvres or collection.
The psoas also influences our breathing and visa versa. If our psoas is tight, it is difficult to properly engage our diaphragm, as the fibres of this muscle are interwoven with our psoas. The location and connective tissue of the diaphragm and psoas cause the action of each to have an effect on the other. So in other words if you aren’t breathing properly your psoas will tighten, your hips will become rigid, your legs will draw closer to your stomach (raised knees) and you’ll loose stability in the saddle! In addition the lack of fluidity in your hips will restrict your horse’s back muscles, preventing him from swinging through!
To tell whether your psoas muscles are tight or overstretched, stand sideways by a mirror (or even better, have a friend take a photo of you from the side) and note the position of your pelvis. If you were to draw a line along your pelvis from back to front, that line should be straight.
If the line tilts downward, your pelvis is anteriorly rotated or moving toward the front of your body. This means that your psoas muscles may be short and tight. If the line runs upward, your pelvis is posteriorly tilted toward the back of your body. This means that your psoas muscles may be overstretched and weak.
Alternatively, if you don’t have a mirror or a friend with a camera you can do the following:
To see if your psoas is tight:
- Lie on an elevated, firm surface (such as a table).
- Hang one leg over the edge and gently hug the other leg in towards your chest, being careful to keep your pelvis from tilting. If you hug it too tightly, your lower back will flatten against the floor, tilting the pelvis out of a neutral position.
- If your hanging leg is hovering in the air and not in contact with the edge of the table, your hip flexors (iliopsoas) are too short and tight.
To see if your psoas is weak:
- Standing up straight, pull one knee in towards your chest as high as you can (above 90 degrees).
- Keeping it there for 30 seconds, notice what is happening. Is your back rounding to compensate for your hip flexors? Were you unable to hold it above a right angle for 30 seconds? If so, you should suspect weakness in your psoas.
One simple exercise that can help you release tension in your psoas is dangling your leg.
You’ll need to do this exercise every day for a week, then every other day for 10 days for it to be effective.
- Stand sideways on the bottom step of a flight of stairs. Hold the banister rail with your left hand and keeping your left foot on the stair, dangle your right leg off the edge of the step. Allow it to hang freely – imagine your foot is made of lead and really allow your leg to drop.
- After 2 minutes, swop legs.
Navasana is a yoga pose that strengthens the psoas isometrically. You can feel the basic action of the psoas in navasana while sitting on a chair. Sit tall on the front edge of the chair, with your arms stretched out in front of you, parallel to the floor. Then lean toward the back of the chair without touching it, while keeping your chest lifted. As soon as your body inclines backward past vertical, gravity is trying to pull your torso down toward the earth, and the psoas contracts to hold you cantilevered.
To apply this action in navasana, move to the floor and sit tall (up on your sitting bones, not rolled back on your tailbone) with your knees bent and feet flat. Wrap your fingers lightly around the tops of your shins and give a little pull to help lift your chest, and then lean back until your elbows are straight. Let go of your shins, keeping your arms parallel to the floor, feet on the floor, and chest lifted. While this is a mild beginner’s version of navasana, you’ll be doing some nice isometric strengthening of the psoas as well as of your back and abdominal muscles.
After you’ve warmed and worked the psoas through contraction, it’s an ideal time to stretch and lengthen it.
Kneel on one knee, placing one leg about two feet in front of the other one, in a position that it forms a 90-degree angle. Now, lean slightly forward, trying to maintain your back straight (neutral spine)! You can keep your arms by your hips but you get a better stretch if you stretch your arms above your head. Hold for 30 seconds, and then relax. Repeat the movement with the other leg.