What is the Psoas?
For those in the know, few muscles in the human body elicit as much interest as the psoas! The psoas is a rope-like muscle located deep in the belly, which starts at the lumbar spine near your lowest ribs and runs to the inside of your femur. The psoas is joined at the hip by the iliacus, which travels from hip to thigh. Together, the psoas and iliacus make up the iliopsoas–your body’s most powerful hip flexor.
As one of the most ‘core’ muscles of your body, it has a central role in your whole body’s alignment, stabilizes your midsection and pelvis, and promotes good posture.
A tight psoas, which can happen if you sit in chairs too much, can be factor in lower back pain, pelvic pain, shallow breathing, a bulging belly, and misalignment that can travel all the way through the body. If your psoas is much tighter on one side, it can pull the spine, hips, and shoulder into serious misalignment- something that could be mistaken for one leg being shorter or something else. This muscle is the epitome of your ‘core’ and as such, if it is weak, there will be a fundamental lack of feeling of strength and even a lack of cohesion as a person.
If the psoas functions properly, it will decrease your low-back curve and allow the spine and abdomen to fall back. The bulging belly settles back in, and gives the feeling of a strong, effortlessly supportive core and strong abdominal muscles.
Why is it important to know about?
I have found that paying attention to this muscle group in my practice will bring about a feeling of clarity, lightness, and energy. My body feels more evenly aligned and I can walk and stand with less effort. Because of the fascia connection of the psoas to the back of the diaphragm, stretching this muscle gives me a sense that I can breathe more fully and easily using the entire diaphragm. Indeed getting balanced in the psoas can be one of the most profound things you can do for your whole body.
The Psoas and the ‘Deep Front Line’
Our muscles are connected to other muscles and internal structures through a bunch of sticky connective tissue called fascia. These connections make one muscle connect to the next along defined lines that go from our feet to our head. There are several such lines that traverse the body- but it is the deep front line in this discussion which is particularly important. The deep front line connects from the flexors of the toes, through the back of the calves, through the inner legs (adductors), into the psoas, the QL and transverse abdominis, to the diaphragm, the heart and lungs, and even up as far as the tongue. The deep front line is the soft tissue foundation of our structure, much like the supporting lines of a tent.
In yoga practice, it is the deep front line that is associated with all of the ‘up’ actions, such as lifting the crown of the head, engaging mula bandha and uddiyana bandha (lifting the pelvic floor and drawing the navel in and up respectively), activating the inner thighs and finding the arch of the feet. Truly, the deep front line is the most important line for yogis to know about!
How this connects to breathing
As you may have caught already, the origin of the psoas at the lumbar spine just below the 12th ribs is where the back of the diaphragm reaches to. Because of the fascia connection along the deep front line, a tight psoas affects the range of movement in the diaphragm. It plays a major role in unlocking our overall ability to move and breathe properly. In fact, poor breathing patterns will have a negative effect on the entire deep front line from the feet to the head. If the diaphragm cannot have full range, the scalenes in the neck act to help take over some of the work to assist in respiration. This can bring about aches and pains in the upper back, and create tightness in the erector spinae, pulling the lumbar into a deeper curve. If better breathing patterns can be established, it has the effect of both relaxing the tone of the hypertonic muscles and increases overall stability and core strength.
To test the flexibility of your psoastry this: Lie on your back with both legs straight. Pull one knee towards your chest. If the straight leg lifts off the floor, then your psoas is tighter than it should be. Now try the other side. Muscular imbalances are common- for a lot of people, if you use your right hand more, the right psoas will be tighter and vice versa. You can also work with a friend by lying on your stomach and lifting one leg at a time. The side that is tighter will show a leg that does not lift as high as the other side.
To test the strength of your psoas, try this: lie on your back with one knee bent. Have a friend put resistance against your knee as you try to bring the knee towards your chest.
Stretch– pull one knee in and straighten the other, pushing the heel away. Move the same arm away as far as possible to lengthen the side body. Feel into the psoas and focus on your inhalations. If the straight leg lifts off the floor it is likely your psoas on that side. Compare the right and the left- often the psoas on the side of your handedness will be tighter (eg- if you are right handed, your right psoas will be tighter)
Stretch – low and high lunges can be helpful but to get more specifically into the psoas and not the other hip flexors (sartorius, rectus femoris), you will want to keep the spine straight. Think for a minute why this is- the psoas connects behind belly into the spine. If the spine is extended as in a backward bend, the length between the origin (the spine) and the insertion (the lesser trochanter) is reduced.
Strengthen – anytime you move your knee towards your chest, including when you are walking, you are employing the use of your hip flexors, in particular, the psoas. It is not necessary to extend the knee / straighten the leg because that is actually more of the work of the quadriceps. Extending the knee however does add extra weight and extra challenge.
Strengthen – This posture can be also a great tool to improve your crow pose (bakasana). Strongly contract your hip flexors to keep the knee towards the chest without resting the knee on the arm.
Once you are finished, be sure to lay on to the floor in corpse pose and deeply relax your belly and allow it to fall towards the floor. Paint a mental picture of how the psoas is connected in your body. Take time to also stand up with your feet spaced open hip width and develop your awareness. When this muscle is balanced, you may find that your breath is easier, and your sense of connectedness is enhanced. Your body’s natural energy will flow better, connecting the lower and upper body.