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.
The push-up excercise requires many muscle groups, but the primary muscle group has to be the chest muscles. the chest includes the pectoralis major and minor. These are the 2 large chest muscles and mainly the pushing muscle group of the upper body. As you are pushing and lowering your body during a push up, the pectoralis major is doing most of the work. As a result, these 2 muscles become very strong and can become defined lean muscle after doing push-ups regularly.