Dr. Laskowski: The pushup is a classic exercise that uses your body weight for resistance. The pushup works the pectoral muscles, which are the muscles in the front of the chest wall. The pushup also works the triceps muscles, which are the muscles in the back of the upper arm. The pushup can be a great core stability exercise if performed properly. The stronger your core muscles, the easier it is to do most physical activities and sports.

Nicole Campbell: To do a modified pushup, position yourself on your hands and knees with your eyes facing the floor. Place your hands slightly greater than shoulder-width apart and your knees comfortably apart. Make sure you contract your abdominal muscles and keep them tight throughout the exercise. Slowly bend your elbows and lower your chest until your chin reaches the ground, then slowly return to the starting position. You'll feel tension in the muscles in your back, your abdominal area and your upper arms.

When you're doing modified pushups, keep your back nice and straight. Be careful not to sag down or arch up. Also keep your movements smooth and controlled. Don't slam down or snap up your body too quickly.

As another option, you can also do modified pushups against a wall. To do a wall pushup, stand up facing a wall. Then lean against the wall with your hands. Keep your knees comfortably apart. Place your hands on the wall at the level of your shoulders, slightly greater than shoulder-width apart. Make sure you contract your abdominal muscles and keep them tight throughout the exercise. Slowly bend your elbows and lower your chest until your chin reaches the wall. Then return to the starting position. You'll feel tension in the muscles in your back, your abdominal area and your upper arm.

When you're doing wall pushups, keep your back straight. Be careful not to sag down or arch up. Also keep your movements smooth and controlled.

Remember, no matter what type of pushup you're doing, keep your body straight, your abdominal muscles contracted, and your movements smooth and controlled. Proper form and technique will help you achieve the best results possible.