Horizontal adduction and internal rotation of the humerus are two of the primary functions of the pectoralis major muscle. To stretch this muscle, you would do the opposite actions and hold the end range as demonstrated in the video below.
This particular stretch done in a power rack is far more effective
than the typical corner or doorway stretch. The key difference is the
barbell – it’s there for a reason! By placing the thighs against the
bar, it helps to deload and stabilize the body allowing you to relax
further, which will heighten the stretch. The bar also allows you to
pivot from the hips, which promotes more external rotation around the
shoulder. It doesn’t look like much, but try it and you’ll feel the
difference.
Focus on your breathing during the stretch by exhaling longer than
you inhale. Exhalation is associated with relaxation – every time you
exhale you’ll notice that you’ll go deeper into the stretch.
Hold the stretch for a good 15 seconds then ease out. Do multiple sets in this manner. You can sequence the stretch before back exercises like rows and chins or before doing behind the neck presses or back squats (the stretch will help get your arms in the proper position under the bar).
Do it regularly and you’ll notice an improvement in your posture and performance in no time.
