Pectoral

The major pectorals are the two large chest muscles (one each side). Each is attached all around the collarbone, sternum (centre of the chest) and down to the sixth rib, and out to the upper part of the humerus (note 1). They pull the arm forwards, for example in push-ups. They have very moderate importance in archery, though they do tend to act after the shot to 'catch' the drawing arm as it travels back in a natural follow-through.

Note 1: The large bone of the upper arm.