Chasing Stronger, Defined Abs?

ABS - Lying Ankle Taps

Take position with your back flat and feet flat on the floor such that the apex created by your knee forms a right angle. Extend your arms outward at the sides of the body. This is the starting position.
Commence the movement by contracting your abdominals and crunching across to the left side of your body. Touch your left hand on your left ankle as you squeeze the abs.
At this point, reverse the movement back to the starting position. Perform the same movement on the opposite side and then continue to alternate.