Perhaps a better way to think about working all of your "core" muscles is to consider all the different directions one's torso can move. It can bend forward and backward, twist right and left and side bend right and left. These are the different planes of movement i.e., sagittal, frontal, and transverse. Any other movements are mere combinations of these.
Crunches, leg lifts and sit ups are movements in the sagittal plane and mainly work the rectus abdominus. Crunches and sit ups should be performed cautiously, as they will often exacerbate existing neck problems. Putting your finger tips at your ears is one way you can avoid common problems usually caused by yanking the head forward. Avoid leg lifts while lying on the floor if you are a beginner, or if you have chronic back pain, as it takes a lot of core strength to maintain a flat spine throughout the movement.
If we look at training these muscles functionally (meaning how we use these muscles on an everyday basis), it becomes apparent that training the rectus abdominus to activate and stabilize while still in a lengthened position is more advantageous. How do we do this? Yep, you guessed it- the dreaded plank. If you are familiar with this one, it means holding the position face down on forearms and toes.
In part 3 we will cover rotational and side bending core exercises. Stay tuned.
