We all recognise the feeling of low back pain. The somatic (bodily) feelings range from dull ache in the bottom of our backs to acute pain radiating down one side and into the leg. Whilst there are many causes of low back pain, it might be tempting to look for the cause of the pain in the back of the body – the low back itself.
However, a common cause of low back pain is found in the front of the body in the psoas muscle (pronounced ‘so-as’). The psoas is a long thick muscle that runs along the edge of the lower back (lumbar spine). This muscle attaches to each of the 5 lumbar vertebrae (see diagram left) and then also connects to the thigh; it connects the lower back to the upper legs. It actually has two parts – the iliopsoas – the iliac muscle joins the psoas part way down.
The psoas has two primary functions:
- When the leg is free to move, as when walking, it is a strong flexor of the thigh at the hip joint.
- When the leg is planted firmly, as when standing or sitting still, it bends the lower spine forward. This action is used to maintain the balance of the trunk when sitting.
Those of us with more sedentary lifestyles who sit at desks or in cars for hours, can foreshorten this muscle. In this way poor posture, or lack of proper use can tighten this muscle.When this muscle becomes tight it can put a strain on the lumbar back and cause lower back pain.
With some lower back pain, by lengthening and releasing this psoas muscle the pain in the back is cured. However, running so deep in the body and being such a strong, long muscle, it can be tricky to treat.
Test for Tight Psoas
The psoas is part of a group of muscles called hip flexors, and is partly responsible for tight hips. People who have low back pain when lying flat on the floor in savasana often have tight psoas.
If you have tight psoas muscles this might be causing your low back pain.
Here is how to test for tight psoas muscles (see picture on right):
- Lie supine on the floor (legs extended along floor and back straight).
- Bring the Right knee bent and over the chest holding around back of knee with hands
- Keep the Left leg extended – toes pointing upwards.
- If you cannot keep the Left leg extended during the test you have a tight left hip (left psoas is tight)Repeat on the opposite side to check the Right hip and psoas.
How Yoga Can Help
In yoga we work hard to stretch and release the psoas in a gentle way. This is done through careful build up and lying and seated hip flexor work and then working towards postures such as Warrior I, pigeon, bridge, dancer etc which all unilaterally or bilaterally stretch and release the psoas if practiced over time.
Back pain is a complex subject with many possible causes: only an individual assessment and treatment plan can work for each person.