As trainers we know, that is isn't necessarily about your athletic your capabilities, or even what you know, BUT how you relay your message. How accurately can you que your client's form? Does your target audience understand the instruction that you are trying to relay?
Using the TRX Suspension Trainer, an active plank is used in all exercises. You can even think of your yogi MOUNTAIN POSE.....the integrity of your plank comes from how well you maintain your posture.
The CF Masses & Spaces explanation approaches the body in sections.
Your head is a mass, neck is the space.
Your chest is a mass your waist is a space.
Your hips are a mass while all your lower extremities are space.
When in your starting position for a TRX ROW, you are standing facing the anchor point and reclined back hanging from straight arms. Check in with your Masses & Spaces. Are you spaces holding true? Are your shoulders creeping up? Are you arching at the waist? Then think of stacking your masses. There should be a straight line from the tip of your head, down through your spine to your tail bone connecting them all. Work that active plank kiddies.
I will let them man himself explain......