Longbow
Bowmen had to practice for many years before they could shoot a longbow well.  Also, longbows are very strong.  This made archers' bodies different from other people's bodies.  The skeletons of medieval bowmen are different from other people's skeletons.  The arm and shoulder bones are thick and a little bent.  These bones supported the large muscles that grew on the archers' arms and backs as they practiced with the bow.  On some archers, the right shoulder was higher than the left shoulder.  This is because archers almost always shot on the same side.  They did not switch hands.