The functional movement called a push up. Why do I encourage pushups by having the chest and thighs make contact with the floor? Can't I just do a push up and break the elbow at 90 degrees or have my humerus (upper arm bone) become parallel to the floor? Sure, you can still benefit from a push up breaking the elbow at 90 degrees however the reason I encourage and instruct the chest and thighs to touch the floor is because of the functionality of the pushup. Generally, when in a push up position pertaining to an every day activity you are laying on your stomach and pressing to a standing position or you have fallen to the ground and have landed on your belly not into a 90 degree bend of the elbow. By practicing the pushup from your stomach you are not only improving your muscular strength but you are also improving your range of motion and appropriate strength needed to press to a standing position from a lying position. If you think it might be easier touching your chest to the floor rather then bending the elbow at 90 degrees, try an experiment. Set a stop watch, start on your belly and press to a full lock out of the elbows, recover to a lying position 50 times as quickly as you can. Can you do this in under 3 minutes? Why not give it a shot.
IF POSSIBLE (due to strength)
Not encouraged / Better Push up
At the bottom of the push-up the chest and thighs should come in contact with the ground, rather than diving the chest, dropping the hips or shorting the depth. To help your push up try to position your feel shoulder width rather than directly together.