This is what she looked like..... Can you spot the error in form?
Elbows directly below the shoulder. Check
Bum tucked under. Check
Abs pulled tight. Check
Shoulder blades squeezed together. DING, DING, DING!!!
Just fixing the shoulder blades changed the plank position to look like this.
Squeezing those shoulder blades together is the KEY to forcing your abdominal muscles to do the work in this exercise. We want the abs to learn to lay flat (and hold in that pooch). They can only truly engage when the shoulder blades are tucked in and down.
Happy Planking Ladies. Tuck those shoulders back and down!