Pectoralis major stretch :
The pec major is the bigger of the two chest muscles, and it is actually two muscles:
The pec major is the bigger of the two chest muscles, and it is
actually two muscles: the clavicular portion on top and the sternal
portion on the bottom. To stretch the clavicular portion, stand in the
corner of a room and place your palms and forearms on each wall. Slide
the arms up so that, with them at 90-degree angles, your elbows align with your armpits. Lean forward until you feel a stretch.
The pec major sternal portion is bigger than the
clavicular portion. The clavicular stretch is more common than the
sternal stretch, yet both are important. To perform this stretch, stand
in the corner with the arms against the walls as in the other stretch.
Open the forearms outward to point at 45-degree angles away from the
body. Lean forward until the stretch is felt, and hold.