Lower Back Anatomy and Back Pain

spinal stenosis

The muscles that surround the lumbar spine on either side, particularly the spinal erectors (also called the erector spinae), are a common site for chronic pain and stiffness. However, most people have no idea how these muscles even work.

The truth is that the function of the spinal erectors is actually quite complicated. By understanding the function of the spinal erectors, you can avoid putting your body in a position that strains this muscle group. This will lead to reduced pain and improved function over time.

Most people assume that the spinal erectors help them extend the back, such as when they bend over and pick an object off the ground. The spinal erectors actually have two sections and functions: the portion of the muscle around the lumbar spine and the portion of the muscle at the mid spine.

The portion around the mid-spine is actually the part of the spinal erectors that helps lift heavy objects off the ground. The portion of the spinal erectors around the lumbar spine has a completely different function. From a structural standpoint, the portion of the muscle around the lower back is way too small to exert enough force to pick up heavy objects. The erector spinae expand in cross-sectional area and get a lot thicker at the mid-spine, which is why the upper portion of the lumbar musculature is dedicated to picking up heavy objects.

The lower portion of the spinal erectors actually holds the lumbar vertebrae in place when you bend forward. This is normally a task that these muscles are built to handle.

Due to the alignment of individual muscle fibers in the erector spinae, this muscle group can only perform its function effectively when the spine is in a neutral position. If the spine is rounded, the orientation of the muscle fibers of the lumbar erectors changes, making it hard for the spinal erectors to do their job properly. As a result, the muscle has to contract much harder to keep the spine in place when it is rounded.

The simple application of this is to always maintain a neutral spine (natural S shape of the spine) when lifting an object. It does not matter if you bend at the hips or at the knees; the only thing that is important is to you keep your spine neutrally aligned so that the lower portion of the erector spinae have a good angle of pull to help keep your lumbar vertebrae stable.

Simply by paying attention to spinal alignment and applying the neutral spine technique to your daily activities, you can significantly reduce your pain and stiffness.