Here’s a variation on the basic push up exercise. By using the swiss ball to create instability, you can increase the activation of the muscles, increase the difficulty of the exercise and improve joint proprioception (internal sense of where you are in space).
Muscles involved: Pectoralis Major (chest), Triceps, Latissimus Dorsi, Rectus Abdominis and External Oblique (abs), and Hip Flexors.
Action: Place a large swiss ball on the floor in front of you. Start with your hands placed evenly on the ball, under your shoulders, and feet on the floor. Slowly lower your upper body down and touch the ball while keeping your spine in a neutral posture. Then push yourself back up. Repeat this exercise for the desired number of repetitions.
Comments: Be sure to avoid hyper-extending your low back. The easiest way to do this is to engage your lower abs and hip flexors to posteriorly rotate your pelvis. And don’t let yourself fall onto the ball. Work that part of the exercise (the negative) by lowering yourself down slowly.
Research has shown that the triceps and rectus abdominis muscles, in particular, exhibit an increase in muscle activity when the hands are placed on an unstable surface during the push up exercise.