Muscle of the Month – December 2019

Erector Spinae

Although often referred to as a single muscle, the erector spinae is actually composed of a group of three different muscles. And rather than put you through another long, drawn out tale of wonder and excitement like in previous months, I am going to condense this one down to one post – much like how the Hobbit compares to the LotR trilogy. ‘Cause let’s be honest, The Two Towers was a little rough.

The erector spinae run basically the entire length of the spine from your lower back to the base of the skull. The muscles lie on either side of the spine and vary in size and structure at different parts of your back. In the lowest region (basically your butt), it is narrow and pointed, and mostly tendinous in structure. In the low back region, it is larger, and forms a thick fleshy mass. Further up the spine it divides into three columns (Iliocostalis, Longissimus, and Spinalis) that gradually diminish in size. A good way to think of the structure is to picture a tree trunk branching out left and right. The erector spinae, in conjunction with the glutes and hamstrings, make up what we call the posterior chain.

The iliocostalis muscle is the furthest from the spine (laterally) of the erector spinae, with the longissimus next, and the spinalis the closest to the spinal column. The spinalis is the smallest of the three muscles with the longissimus being the largest. Together, the erector spinae assist in the control of bending forward at the waist as well as acting as powerful extensors to return the back to the erect position (think deadlifts and good mornings). The erector spinae are assisted by the hamstrings and glutes during the extension and straightening of the spine, however, since they are significantly smaller than the glutes and hamstrings, it is often the erector spinae that give out first during heavy deadlifts and other hinging movements. I speak from personal experience, and I’m sure many of you have experienced this as well, but this is often the muscle group that is most injured, and when people complain about back pain, these guys are usually the culprit.

To strengthen the erector spinae, we should work on hinging movements such as deadlifts, kettlebell swings, hip extensions, and reverse hyperextensions. If the erectors are currently giving you pain, TALK TO A COACH AND SEEK HELP! This blog is not the place to turn to if you are experiencing pain. However, to give the erectors some love, try smashing your glutes (especially the glute medius/minor aka the “side butt”).