Do you need stronger back muscles?

When people come to me with back pain they often talk about strengthening their back. The thing is a ‘weak’ back is rarely the cause of lower back pain. After all, there are plenty of strong people who have bad backs and plenty of weaker people who don’t.

But if that is not the answer to back pain, what is?

As with many things, it’s more complicated than you might think.

Lower back muscles: what is strength?

The strength of the lower back muscles is the force or tension that a muscle, or more correctly a muscle group, can exert against a resistance in one maximal effort. By maximal effort we mean using the greatest amount of strength they can use at that one time. But when we’re talking about back pain that happens over a period of time, there has to be more to it than a problem with that one-time strength.

To try to understand it we have to look at the function of the muscles.

What is back pain?

Put simply, back pain is pain that originates from the lower back. Sounds simple, doesn’t it, but there are a lot of possibilities within that. In other tutorials I have talked about non-specific lower back pain, where we don’t understand where the pain is coming from. It could be from the vertebrae, the facet joints, the discs, or from the nerves touching the discs.

We need to try to understand all these things, perhaps needing scans or further investigations to really get to the bottom of the problem. And besides, in all of these cases simply strengthening the back muscles will not do a great deal to help. You can find out more about why in the video above.

With regards to the lower back muscles, though, if that is where the problem is coming from, it is still unlikely to be a problem with strength. More likely it is because the muscles are tight. So then we start asking questions:

• Why are the lower back muscles tight?
• Is there some instability there?
• Is it a trigger point where the pain is coming from elsewhere? And if so which muscle is it coming from?
• Is it just that there is a knot that needs to be worked out?

A bit about back muscle function

Lower back muscles do not work in isolation. Which is why there is no point in isolating the muscles with exercises like back extensions. Back strength really is one example of where the whole is greater than the sum of the parts. Here we’re talking about the torso and core, the QL, longissimus, Iliocostalis, all the muscles down the sides of the spine, glute max. and the lats, not to mention the Thoracolumbar fascia that sits over the top of it all. When we talk about strength we’re really talking about the strength of the entire torso; the strength across the entire back.

So we don’t necessarily need stronger low back muscles as such, what we need is a lower back that is working correctly.

What do we mean by a lower back that is working correctly?

We ask a lot of our muscles every day, particularly those in the lower back. We need them to fire at the right time so that they’re online and activated when we need them. And we need good endurance. One of the key reasons muscles become tight or spasmodic is that they get fatigued. They just latch on and hold tight. Building endurance can help muscles to resist this fatigue, allowing them to perform better for longer, so that the muscles can resist fatigue.

So, to tackle the problem we have to address the pain, build the stability, then the endurance...and only after that comes strength.

The other major function of lower back muscles is to neutralise the anterior shear.

Picture this. You’re doing a deadlift. You lean forwards. As you bend, the vertebrae in your spine want to fall forward, with gravity. We call this the anterior shear force. So the large lats and glutes contract, which in turn activate the muscles along the back of the vertebrae. These muscles, along with the thoracolumbar fascia, create an anchor, providing a backwards pull and neutralising that forwards force. This holds the spine in position.

We can see that in this case this muscle group is effectively acting like our postural muscles, helping to maintain the natural curve in the spine. We allow the spine to round? The muscles relax and we lose that ability to neutralise the anterior shear. This can cause issues with disc and nerve health.

So rather than simply performing exercises designed to strengthen those lower back muscles, it’s much better to understand their function and then build up the stability and the endurance. And then if your fitness goal is strength, you can start working on that too – but that would not normally be part of your rehabilitation goal.