Yesterday (or the day before) Kelly and I were discussing form because my low back was collapsing during the push-up. When I tried doing regular push-ups this didn't happen so something was going wrong. She suggested focusing on the tilt of my pelvis. If it was tilted forward instead of neutral it would cause my lower back to collapse.
Sure enough that was the issue - now my plank doesn't feel completely in line to me because my butt is up but my back and pelvis are all straight. Kelly also searched out another great video that helped her see that she was relying on her wrists to catch her weight because she wasn't squatting enough. This video really highlights how he is able to put his hands on the ground and squat down and his knees come close to his elbows.
Form is going to be really important as we get in bigger numbers so take the time to improve it. Good form helps you get the complete benefit from this "whole body" exercise and reduces risk for injury.
Oh and today on day six while my back isn't collapsing I could barely do push-up six. My goal was to not have to do push-ups on my knees...here is hoping!
The video here also has another full body exercise that shows me how inflexible my hips are