The Bench Press: Big Pecs, Bummed Shoulders

November 9, 2009 | by Dr. Jess

The bench press is one of the best ways to grow big muscles in the chest so it’s no wonder why so many gym-goers routinely use it in their exercise repertoire. However, the bench press is becoming more and more blamed for ruining weight lifters’ shoulders. I’d like to shed some light on the biomechanics of bench press injuries. The Bench: The bench itself can cause shoulder injuries by restricting the normal motion of the shoulder blades (scapulae). In turn, the shoulder joint (glenohumeral joint) will have to move excessively to compensate for the restricted movement of the scapulae. I often tell my patients that most athletes’ bodies will figure out how to get from point A to point B with obstacles in the way. Unfortunately, they don’t realize that they are using the wrong muscles or joints to compensate and thus, they get injured. The bench can prevent the shoulder blades from going back flat against the rib cage and towards the spine. If this happens, the shoulder blades are now rounded forward, but in order to lower the weight all the way down to the chest, the “ball” must move while it is not centered in the socket. (The shoulder blades house the “socket” in which the ball must sit centered on.) This can be very dangerous for the shoulder joint itself and the external rotation rotator cuff muscles that attach to it as the external rotators will become tight and the internal rotator cuff muscle (Subscapularis) will become weak. This causes the “ball” to move forward and up causing injury and pain. This is true for those who have pain doing a bench press, but no pain performing a push-up. For those of you who have pain doing both, you may have already injured the shoulder joint or the tissues surrounding or attaching to the shoulder. The Bar: As the weight lifter pushes up, the forearm, wrist and elbow joints move into supination to allow the shoulder to stay in neutral or slight external rotation, which is safer for the shoulder joint. However, the bar restricts supination of the forearm, and thus causes some internal rotation of the shoulder joint possibly leading to impingement. Ideally, to overcome this biomechanical problem, the weight lifter can use free weights, which allow normal movement of the elbows and wrists and shoulders during a press. Still want to Bench Press? Follow these suggestions to reduce the risk of injuries. 1. Place a pool noodle about 10 cm or less in diameter along the bench. Then lay on the noodle so the noodle is along your spine and your shoulder blades can roam freely. A half foam roller will do, but do not use a full foam roller unless you are on the floor. 2. Tie red tubing around each end of the bar and then have your spotter pull on the center of the tube away from your head at bar height so as to make a “V” with the tubing. The point of the “V” will be at the spotter’s hand and the opening of the V will be at the bar. As you lower and lift the bar, your internal rotator muscle (Subscapularis) has to activate. 3. As you lower the weight and the elbows lower past the bar, make sure your chest opens up via the shoulder blades moving towards your spine. Once the shoulder blades stop moving, then do not lower the elbows any more. 4. When pushing up, focus on allowing the shoulder blades rounding around your rib cage (away from the spine) WITHOUT hiking up your shoulders to your ears or rounding or flexing the back. This is very important, as you will feel like you are punching your arms towards the ceiling, which activates the Serratus Anterior muscle. The Serratus Anterior muscle has a large influence on Scapular Stabilization, which is necessary to decrease the risk of injury. Adapted from Sports Injury Bulletin, Issue No. 80.