Step 1: Begin the movement on your knees and forearms, with your feet in the TRX stirrups (facing down). The TRX straps are several inches above the floor.
Step 2: Your head is in line with your shoulders and knees at this point; also, your shoulders are stacked above your elbows.
Step 3: Next, lift your knees off the floor so that your hips are in a straight line with your shoulders, ankles, and head; shoulders are still stacked above your elbows. Keep your abs engaged, your glutes tight, and your shoulder blades depressed and somewhat separated.
Step 4: After holding this position from 10 seconds to 2 minutes, lower your knees back to the floor to regroup.
Step 5: Repeat several times.
How to progress the exercise
The advanced version of this exercise is, of course, from the standing position. A good progression to this would be to start standing, and slowly lower yourself towards the floor, then go back onto your knees to press yourself up. You are basically training the ‘negative’ or lowering portion of this exercise, eventually working your way to the full movement with a fully extended body. By kneeling on a BOSU, you will increase the work done on your core.
This requires a good strong core in order to focus on protecting the spine during this movement, which has a greater susceptibility to injury from a dynamic movement such as this. A strong stationary plank is mandatory, but maintaining a strong plank within this dynamic movement is ideal.