"The pushup is one of the most basic and effective upper body exercises. Although it’s a fairly simple exercise, most people make a lot of mistakes. These five tips turn the standard push up from a chest/shoulders/triceps move into a full body exercise which means more muscle, increased strength and faster results.
1. Brace Your Core
To avoid rounding your spine and doing “banana back” pushups, try squeezing or "bracing" your core. Imagine that you're going to get punched in the belly. Naturally, you’ll flex to guard. Bracing reduces the risk of injury by enforcing a neutral spine and engages your core, making the pushup of a full body exercise.
2. Squeeze Your Glutes
Your glutes are the one of biggest muscle groups in your body and often times the most inactive. By squeezing your glutes you will protect your lower back, improve posture, provide full body tension and help maintain a neutral spine.
3. Pack Your Elbows
A common tendency during pushups is to flare your elbows wide - a mistake and can lead to shoulder and rotator cuff issues. Instead, pack your elbows in towards your sides, trying to have less space between your armpits. “Stack” your joints, with your hands under your elbows, and your elbows under your shoulders. This will improve long-term shoulder health and recruit your triceps and lats more. Having joints in line also creates better range of motion in the shoulders and chest.
4. Grip The Floor
Instead of having your fingers together and pointing straight up, try this instead: Change your hand position so your thumbs are facing each other. Next open your fingers and grip the floor. This immediately creates more full body tension, tightens the lats and triceps and helps engage more upper back muscles.
5. Push The Ground Away From You
Instead of pushing yourself off the ground, think of pushing the floor away from you. This force production translates into full body tension and creates a bracing effect throughout the whole body. By pushing the ground away from you, you’ll use more muscles making the push up more of a full body exercise."