Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
The pectoralis major is a large muscle in the upper chest, fanning across the chest from the shoulder to the sternum. It is responsible for movements such as flexing, rotating, and adducting the arm.
Deltoid: A triangular muscle on the shoulder that is involved in arm rotation and stabilization.
Latissimus dorsi: A broad muscle on the back that supports arm movement and contributes to the motion of pulling things towards oneself.
Sternal: Pertaining to the sternum (breastbone), often used in reference to parts of muscles attached to the sternum, like parts of the pectoralis major