The quadratus lumborum (QL) muscle may not be one you have heard of but it is almost certainly one that has given you grief at one point or another, particularly if you;
- sit with your legs crossed,
- are pregnant
- favour carrying your children on one side,
- regularly bend and twist to one side e.g. gardening, playing golf
- run on uneven surfaces
- lift heavy objects
- have a leg length discrepancy, pelvic tilt or scoliosis
The list is extensive!
So where is this muscle? The QL is a deep rectangular muscle made up of fibres running in varying directions in the lower back. More precisely it runs from your iliac crest (upper pelvis at the side) to your lumbar spine and lowest (12th) rib. There is one on each side and it's main role is to stabilise the spine. Acting together they extend the spine and working alone they side-bend it. It also plays a role in respiration, assisting the diaphragm on inspiration.
The clinical significance of this muscle is that it plays a major role in lower back pain. Poor posture and repetitive dysfunctional movements will cause the QL muscle to become a primary source of pain but it also often reacts to other lower back joint, disc and nerve issues by going into a protective spasm. None of these are pleasant!
A dysfunctional QL that has become overly contracted and isn't being looked after (i.e. stretched) will suffer a reduced blood flow and is at risk of painful spasm and trigger points.
Trigger points are hypersensitive areas of muscle that refer pain to other areas and in the case of the QL muscle they will mostly cause pain at the sacro-iliac joint (posterior pelvis) and buttock, but occasionally the side of hip too, as shown (crosses indicate trigger points, red areas show referral sites)
Additionally as the QL muscles are antagonists of one another, if you have pain one side you will invariably have it the other side too! For this reason, osteopaths will generally work both sides of the body to rebalance these muscles and their trigger points, as well as re-aligning the joints the QL attaches too and using deep massage and stretching techniques.
However, it is vital this muscle is given a little bit of TLC at home too - most importantly gentle regular stretching (click here for a video link)
but let's not forget some strengthening exercises too - most people have one side stronger than the other which is particularly evident when doing side-plank dips (as we all do, of course...) and the increased blood flow when exercising this area is great for reducing trigger point pain.
So that's the QL muscle in a nutshell. There are additional, more complex factors that can affect the QL - an example is superficial back muscle weakness through poor seated desk posture that places excessive strain on the QL. Furthermore, a problematic QL muscle is often linked to pain and dysfunction in the gluteal (buttock) muscles which have there own trigger points running down the leg. This is how the osteopathic picture all fits together, and partly explains how a pain in the middle of your leg can be explained by poor seated posture and weak back muscles!
If you think your QL may be in trouble and have any further questions on the potential causes of lower back pain please feel free to get in touch at email@example.com or 01895 200050.