Straight Arm Planks with Knee Tucks
How to: From a straight arm plank position with a neutral spine and abdomen tight. Slowly draw 1 knee towards your arm. Bring the knee in as far as you can go without rounding the lower back or spine.
Compensations: Watch for your hips dropping and or rotating, they must stay neutral and show no movement. Watch for elevating of shoulders, rounding of spine and dropping of head.