Let’s use the Spinal Erectors as an example. The muscles that doctors generically refer to as the “Spinal Erectors” or Erector Spinae are actually made up of several different muscles. And each one of these different muscles has dozens (sometimes hundreds) of parts to it. On top of that, each individual part has its own tendinous attachment point. When you look at the picture above, notice the amazing number of tendons. And remember that they are just showing a small portion of this muscle. And this is not even touching on the THORACOLUMBAR FASCIA.