The Psoas (pronounced so-ass) is an incredibly important muscle that many people don’t think about, but stretching and strengthening the Psoas can make all the difference to our well-being.

If you have low back pain, hip pain, or various other tightness and stress in your body, stretching and/or strengthening the Psoas can potentially completely fix these issues. The Psoas affects our posture and helps stabilize the spine. If it is either too tight, or too weak, it can cause lower back and/or pelvic pain.

Although the Psoas is a really important muscle, it is also relatively unknown. You cannot see the Psoas and as it does not appear on surface muscles of the body charts, many people have only a vague idea of where it is located. 

The Psoas is actually the biggest and strongest muscle in the group of muscles referred to as hip flexors and originates from the lateral surfaces of the 12th thoracic vertebra and then forms a strip of muscle almost as big as a wrist along each side of the lumbar spine. Looking at the front of the body, you’d have to remove the intestines and other organs, to be able to see the muscle as they lie at the very back of the abdomen. From the lumbar vertebrae the Psoas proceeds forward and down, crossing the outer edge of each pubis, before moving back again to attach to a bony prominence of the inner thigh bone called the Lesser Trochanter. Along the way, the Psoas joins with the Iliacus, which originates on the inner bowl of the pelvis (or the ilium) and together they form the Iliopsoas. 

A tight Psoas can cause serious postural problems as it it pulls the lower back vertebrae forward and down toward the thigh, often resulting in lordosis (overarching in 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. A tight Psoas on just one side can cause pelvic rotation and even knee pain on that side. 

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 (posterior tilt). This misalignment is characterised by tight hamstrings pulling down on the sitting bones, a vertical Sacrum (instead of its usual gentle forward tilt), and a flattened lumbar spine. Without its normal curve, the low back is weakened and vulnerable to injury, especially at the intervertebral discs.

Finally, it is possible for your Psoas muscles to be both tight and overstretched. In this case, your pelvis is pulled forward in front of your center of gravity, causing your back to curve (swayback) and your head to poke forward. 

So basically it doesn’t matter whether your Psoas muscles are weak or tight, either way, your posture suffers and your lower spinal column is put under more pressure than it’s meant to take.

For horse riders the Psoas muscles are the ‘missing-link’ riders must learn to use in order to easily feel their horses’ movement and to follow the directions of their riding instructors. Balanced flexion of the Psoas muscles enables riders to tone the inside of their upper thighs and to follow the movement of their horses with their pelvis. By mastering the use of these muscles, riders will be able to maintain self-carriage, both on and off the horse.


Now that you have a picture of the Psoas in your mind, let’s see if you can feel it contracting. When the Psoas contracts, it will pull the thigh and the spine closer together (hip flexion). If you are lying on your back, contracting the right Psoas will help lift your right leg off the floor. If you place the fingers of your right hand halfway between your hip knobble and your pubic bone and press inwards you should feel your Psoas cupping, or smiling as you lift the leg. Now try it with your left leg – can you feel a difference between the left and right?


Lie on your back in relaxation position and then float both knees up into a double knee fold. Grab hold of your right knee with both hands and pull it into your chest, then lower your left leg and straighten it out along the mat. If your Psoas is tight then your left leg/knee will not be able to touch the ground. Do the same with the other leg – and don’t be surmised if you get a different result. One Psoas can be tighter than the other.


Stand with your back against a wall with your heels about 3 or 4 inches in from the wall. Raise your right knee (without using your hands, or creating a C curve in your spine) and hold it up for a count of 30. If your thigh comes above 90 degrees your Psoas is strong, if you can’t get the thigh to 90 degrees, or can’t hold it there, then your Psoas is weak. Repeat on the other side.

There are a number of Pilates exercises and stretches you can do to strengthen and stretch the Psoas muscles. For nice healthy Psoas muscles you need to do both. 


  • Standing Pelvic Tilt
  • Warrior One
  • Kneeling Lunge
  • Kneeling Lunge with Side Stretch
  • Runners Lunge
  • Half Frog
  • Bridge
  • Whole Body Stretch


  • Single Knee Fold & March
  • Boat
  • Single Leg Raise
  • Double Leg Raise & Lower
  • Criss Cross
  • Roll Over
  • Roll Like a Ball
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