The pectoralis major muscle does the following:
- Abducts the arm at the shoulder.This means that the pectoralis major muscle moves the upper arm away from the vertical midline of the body (i.e. the action of raising your arms to the side).
- Medially rotates the upper arm.This means that the pectoralis major muscle rotates the upper arm inward around the axis of the bone (i.e. it rotates the upper arm toward the vertical midline of the body).
The muscular anatomy image shown here is in the public domain. It may have been modified by ShapeSense.com, but was originally acquired at the following address:http://en.wikipedia.org/wiki/File:Pectoralis_major.png