The lower back muscles are usually bundled together to encompass a generic term of 'lower back'. Many people who present with pain in this area actually find that the pain stems from a weakness in the stability of the core or a tightness in the legs as per previous blogs. Apart from the smaller Erector Spinae group (see previous BLOG) the Quadratus Lumborum are possibly the most prominent musculature that encompasses the 'lower back' group.
The Quadratus Lumborum (QL) originiates at the iliac crest (crest of pelvic bone) and inserts at the inferior border of the 12th rib and transverse process' of L1 - L4 (bottom rib and side of spinal segments). It lies deep to the Erector Spinae group of muscles and acts directly in trunk extension and lateral flexion. Whilst it's main function is to laterally flex the trunk, the QL are very active in the supporting role of spinal extension.
The lower back contravenes the assumption that muscles that are stretched beyond the normal range tend to exhibit weakness. In the case of the lower back, excessive flexion in someone such as a gymnast or diver, does not exhibit weakness, but rather normal strength. Whilst the QL is subject to the strength of the Erector group in extension, it is a primary mover in lateral flexion and also somewhat in rotation of the lower spine. A golfer or Baseball player will exhibit large amounts of stabilising and active strength with the QL in the rotation of the spine and the power generated in a swing.
Whilst rotation is performed by the erector group and the larger muscles such as the trapezius and latissimus dorsi further up the trunk, the extension/flexion of the iliac crest that naturally comes with a ‘swinging’ or ‘rotational’ motion falls to the QL. For example, in a baseball swing, the side which stabilises against the motion of the arms naturally contracts and shortens with the swing of the trunk and arms. In other movements, the QL can be called upon in hip abduction (moving the leg away from the body) and where power is insufficient in the Gluteals, the QL (with the Tensor Facia Latta) once again becomes the primary mover. The poor QL is never the star but often the ‘cover’, being called upon when necessary and the primary mover is too tired to perform.
An injury in the QL gives broad pain radiating from the pelvis upward towards the bottom rib. It is usually one sided (rather than a broad flat pain across the bottom of the spine/sacrum) and being able to bend sideways is most difficult. It can also create issues with extension(when the QL work together) if the hip flexors are traditionally tight because the QL have been used to extend the spine; thus where there once was power, there now is none.
The seated position is where the QL becomes quite loaded. With hips in constant flexion the iliac crest is pulled downwards and this places stress on the QL as it is in constant contraction to battle the pull of the hip flexors. (See our article on forces acting on the pelvis)In this way, muscular fatigue can exhaust the QL and result in reduced blood flow, adhesions and possible spasming. Often it is the smallest movement, typically a bend forward combined with rotation such as in picking up an object dropped on the floor, that results in the QL spasming and a locked back. There are various diagnostic tests to see whether a lowback spasm is in response to tight hip flexors, tight QL or overtight leg muscles.
Perhaps the most pertinent question I am asked when I expose the influence of the QL is “how do I stretch it?” This isa particularly difficult muscle to target in a stretch as it relies very much on the stabilization of the iliac crest and this depends largely on the tension inherent in the hip flexors. Typically movements to stretch the QL involve lateral flexion of the spine. The trick is to get the alternative side stable before enacting the stretch to really target the QL.
The Doorway Stretch
This is often used as the primary stretch but is often dependent on the person getting the hip position. It often involves the athlete adjusting the position of the hips to really target and ‘feel’ the stretch in the correct position
The Straddle Stretch
Men will struggle with this one. It feels dreadful if you cannot get in the right position and often results in spasming on the alternative side if you are not used to putting your spine in lateral flexion. Doing this seated and looking ‘up under your armpit’ is usually the best way to target this stretch – if you can manage it.
The Backward Dog Stretch
This is another good version where you mimic the famous ‘downward dog’ position but with one arm twisting beyond the reach of the other. It is also down on the knees. Again the trick here is to ensure the hips remain parallel or even dropping the focus hip downwards towards the floor to target the QL.
In all these stretches, getting the arms into an overhead position and stretching away from that is primary. This places the pelvis into a base position and pulls on the ribs, thus elongating the QL.
It’s one of the trickiest muscles to stretch and target but it really is an important muscle to maintain and utilize. Loading up a QL with weighted resistance is a bit like loading up the abdominals. These muscles are meant to be ‘thick and bulky’. They are meant to have length and be long and supple to enable good quality function – and avoid the dreaded lower back spasm.
So spare a though for the poor QL. Even it’s namesake the Quadriceps are a much more higher profile muscle and the function that the QL performs is often forgotten in the supporting role when the main mover decides to have a night off or go for a ‘smoko’. So be kind – and it will work well for you.