COMMISSIONED OFFICER. Commissioned Officers are the managers, problem solvers, key influencers and planners who lead Enlisted Soldiers in all situations. Enlisted Soldiers perform specific job functions and have the knowledge that ensures the success of their unit's current mission within the Army.
The primary difference between chin-ups and pull-ups is that chin-ups are done with a supinated grip, palms facing in toward the exerciser. This sets up the mechanics so that chin-ups, while still primarily a back exercise, also provide a good arm workout, particularly for the biceps.
To answer these questions, it is necessary to take a look at the muscles of your upper body. The short answer to the question, what muscles do push ups work is that they work the muscles of your upper torso. This is a simplification however. Muscles of the upper back (latissimus dorsi, rhomboids and trapezius).