Doorway Pec Stretch

If you have been around me for long, you probably know my position on stretching. If not, here is a brief synopsis: muscles do not stretch. Stretching in and of itself isn’t necessarily a waste of time, but we should be more specific when we describe the mechanisms. Muscles are bound in layers of connective tissue, that’s the elastic stuff that stretches. If you have participated in any physical rehabilitation for shoulder, back or neck pain then you have probably come across the doorway pec stretch. Although the intention is to improve mobility of the shoulder and chest wall, more subtle alterations are occurring that lead to the changes we see.

The pectoral muscles, of which there are two by tradition, attach to the front of the chest wall and the upper arm as well as the front aspect of the shoulder blade. The idea behind the doorway pec stretch is to put the pectoral muscles on length to aid in achieving a more upright position as well as to open up the shoulder for greater mobility. The stretch itself might provide a transient change in connective tissue elasticity and thereby improve shoulder range of motion. This occurs at both attachment sites. What is often underappreciated is the sternum and ribs contributions to the changes made.

When the arm is anchored to a doorway, it promotes the forward movement of the sternum and rib cage. That forward movement is necessary for shoulder mobility and might be part of the reason we see improvements in range of motion after the stretch. The forward motion is created by compression of the shoulder blade on the backside of the rib cage as a product of the arm being anchored in the doorway. That drives the sternum and ribs forward, creating space that is utilized by the shoulder for active motion.

Stretching can have a place in a fitness or rehab program. Our interpretation of what is stretching needs refined, as well as the locations of the mechanisms at play. The rib cage and sternum play a large part in how the shoulder moves. If we anchor the arm to a doorway for a pec stretch, that frees up the ribs/sternum for greater movement thereby increasing shoulder range of motion. If we can appreciate the more subtle changes taking place during movement our prescription will most likely be much more effective.

Austin Ulrich, Physical Therapist