Side Plank (modified & regular)
How to: From a side lying position, place your elbow directly below your shoulder with both feet on top of one another. Draw your navel inwards and elevate your hips off the ground until your spine is straight in a neutral position with your head and neck. Be sure to have the chest open & shoulders vertically stacked. If you find this difficult, begin from your knees.
Compensations: Watch for rolling the shoulders forward, dropping your head, rounding or elevating shoulders and moving your hips back.