It's a sad truth, but being in the fitness world, I see more bad planks than good. Don't get me wrong when I say “bad”, by that I mean incorrect form.
The reason for this isn't because decide to have incorrect form, they just don't know! So let me break it down for you so the next time you're working on those 8 pack abs, you won’t injure yourself along the way.
Start in a table top position:
Hands are wide on the floor, wrist creases are parallel to the front of the room
Shoulders are stacked on top of the wrist
Hips are directly on top of the knees
Shins are pressing down into the floor
Once you have this alignment, you are ready for the next stage...full plank
Your upper body stays exactly the same, only thing that changes is your lower body
Straighten the legs, lift from your inner thighs and back of the knees
Tuck your hip bones towards your ribs
Puff up the space in between your shoulder blades
With strength push into the pointer finger and thumb
Don’t forget about your neck!
Gaze is down your nose so spine is in neutral