Back and shoulders dominate posture. The pecs support the scapula and shoulder joint, helping to preserve posture and upright stability.
The triangle pec minor, which joins to the middle of your third, fourth, and fifth ribs, is very useful. Breathing in expands the pec minor, expanding your rib cage.
Seedman says many women and other breast owners avoid chest workouts because they assume they'll reduce their breasts, but they're actually like a non-surgical breast augmentation.
Your pecs help you lift groceries, open heavy doors, and carry a suitcase around an airport. Seedman believes the pectoral muscles are involved in most upper-body motions.
As said, pecs are massive, vital muscles. They also activate the shoulders, back, and triceps, making chest exercises great upper-body workouts.