The value of lower back flexibility has become a controversial and debated topic in recent years.  Many therapists and clinicians even hold spine flexibility as a less desirable trait. Something to be avoided. This stems from the belief that excessive motion leads to strain and inevitable injury of this “vulnerable” area.

I don’t understand this thinking. If the lower back was not meant to move it wouldn’t have evolved to be so mobile. But it did. The spines we have today are extremely mobile for a reason. Natural selection must have favored this structure because it provided an advantage. Our mobile spine allows us to bend, lift, twist, walk, reach up overhead, or pick things up off the ground.

So to build and maintain a healthy spine we must ensure the lower back is flexible. Of couse, this basic principle applies throughout the body. But as we will see, developing spine flexibility has several unique challenges. Before we get to that though, we need to talk about just how important a flexible spine really is.

Use It Or Lose It

We know movement and physical stress is essential for tissue health. This is the use-it-or-lose-it principle. If I go to the gym and perform dumbbell curls my biceps become bigger and stronger. Cancel my gym membership and my muscles get smaller and less capable.

We are all familiar with this concept. But this principle of adaptation applies far beyond muscle strength. The same principle applies to our hear and lungs, our immune system, and the neural connections within our brain and spinal cord.  And it also applies to flexibility. So if muscles and joints don’t keep moving, they won’t be able to keep moving.

Of course muscle weakness, a loss of flexibility, or difficulty walking up a steep flight of stairs relate to changes in function. These are easy to conceptualize. But what is far less appreciated is how these changes affect the body on a cellular level. Especially with respect to health and structural integrity of the spine over time.

All Tissues Need Movement

It is well known that muscles atrophy in the absence of physical loading. But the same will happen with other tissues within and around a restricted joint. For example, following joint immobilization ligaments become weaker, which can lead to joint instability and ligament failure at lower loads. The joint capsule will tighten and become fibrotic. This leads to further ROM limitations and changes in afferentation. Thinning and degeneration of articular cartilage is also seen. So contrary to widely held beliefs, thinking of osteoarthritis as a wear-and-tear disease is  simply not accurate. Here we can see too little load also has far-reaching detrimental effects on joint health.

Given these findings, we can see how spine flexibility is critical not only from a functional perspective. But also to maintain tissue and structural integrity.

The Problem With Lower Back Stretches?

So if we want a flexible spine we need to keep moving the spine. And this motion needs to occur on a regular, ongoing basis. Many clinicians and therapists will prescribe various spinal stretches and yoga postures here (Fig. 1). On the surface this seems like a reasonable and effective strategy. After all, the efficacy of improving flexibility and joint ROM is well established. And this does seems to work so well at other areas like the hips, hamstrings, or shoulders.

Figure 1. Traditional lower back and yoga-type stretches create some generalized motion through the lower back. But they make no attempt to focus the movement through the individual spinal joints. Here motion will tend to occur though joints that are already mobile as opposed to more restricted segments.