Analysis of the pilates push-up (the lowering and pushing phases) (JT)

Introduction:
The push-up is a classic exercise to strengthen the upper body. If you break down and observe the complex movements in a push up,  you will see that it activates many muscles in the upper body both concentrically and eccentrically.
Starting position:
You start by lying down in prone position on the floor with feet together. Your hands are  placed under your shoulders, palms facing down. From here, you will tuck your toes under and push your body away from the floor until your arms are straight, ensuring that your shoulders, hips, knees and feet are in one straight line.
The up/pushing phase:
In this phase, the motions are in your elbow, shoulder and scapulae. The triceps brachii muscle contracts to extend the elbow. The pectoralis major, deltoids, biceps, and coracobrachialis muscles contract to allow the shoulder joint to horizontally adduct, which occurs when your upper arms move horizontally toward the midline of your body. Your scapulae are abducted (i.e. they move horizontally away the midline of your body) and protracted, moving forward as they round the back of your ribcage. For this, the serratus anterior and pectoralis minor are activated.
The down/lowering phase:
In this phase, the same muscles that are activated in the pushing phase remain active, but now working eccentrically. For instance, your triceps now work eccentrically to allow flexion in the elbow. The pectoralis major, deltoids, biceps, and coracobrachialis muscles work eccentrically to allow the shoulder joint to horizontally abduct. This will control the lowering of your body and prevent it from falling to the floor. At the scapula, the serratus anterior and pectoralis minor eccentrically contract to allow for scapula adduction. Note that for the pilates push-up, we keep the elbows close to the body and pointing to wards your legs as you lower yourself.
Note on  scapula stabilisation:
The combination of gravity and body weight may make the scapulae “over-retract/adduct”. Engagement of the scapula abductor muscles (i.e. serratus anterior and pec major/minor) will help to keep the scapulae stable and “wide”.
JT
( with reference from
Clippinger, K. (2007). Dance Anatomy and Kinesiology: Principles and exercises for improving technique and avoiding common injuries. Champaign, IL.: Human Kinetics)