5 Exercises To Strengthen Your Erector Spinae Muscles | Well+Good The erector spinae are a group of rope-like muscles that run up and down the sides of your spine. They’re largely responsible for stabilizing the back and allowing us to freely rotate, bend, and extend. According to Deidre Douglas, EdD, a Les Mills US presenter and instructor, it’s this column of muscles that plays such a vital role in good posture. |