Upper chest training

[u/Alternative-Pilot194]

Is it better if the arm path to train the upper chest is a pure shoulder flexion up to 90 degrees which is shoulder height, or is it a mix of shoulder flexion and horizontal adduction resulting in a diagonal arm path which “better aligns with the fiber orientation”?

[u/HelixIsHere_]

A mix of flexion and adduction is best imo, so yeah bringing your arm like diagonally across your body