Rule 2. As your elbow moves out away from your body provide the force from your shoulder to externally rotate it.
This rule deals with what muscles you want to be activating while your elbow moves away from your body and then being able to sustain that shoulder position under the load. This will happen while pressing the bar away in a bench press or overhead press. It could also be while you lower yourself during the pull-up, press yourself up during push-ups, or while sustaining an overhead barbell or dumbbell position. To imagine this in another way, if you were holding a dumbbell, as you pressed away from your body the thumb would rotate out to the side and your palm would face you. There are a couple reasons why this is important and advantageous:
- This can help avoid the onset of or decrease shoulder pain. There is not a lot of space between the ball and socket shoulder joint and the hard protective shelf above it called your acromion process. By externally rotating your shoulder during overhead movements, you maintain more space between these structures, which decreases the pinching of the soft tissues in this space. That pinching is often called “impingement” and can be the cause of that all too common non-traumatic shoulder pain.
- This creates a more stable shoulder. The external rotation will take out the slack of the connective tissue at the joint capsule increasing the static stability. The external rotation of the humerus (long bone of the arm) also facilitates an improved socket position by aiding in upward rotation of the scapula (shoulder blade). This also improves stability by creating boney shelf for the ball of the socket to rest on when pressing or sustaining loads above shoulder height.
These shoulder rules sound pretty easy to follow, but they are often very challenging if you lack mobility and/or control, or if you throw fatigue and heavy loads into the picture. You can probably think of a movement or exercise to which this may not apply, but for most strength and body weight movements these two rules will keep you safe, help you break through plateaus, and likely decrease pain. Remember that retooling a movement may result in a temporary decrease in performance, but in the long run performing movements the right way will always get you closer to your genetic potential.