A:  Not necessarily. Truth is, ab workouts should focus on isolation. However you are able to achieve that isolation is what you ought to go with. Some people can really bear down on their abs on an abdominal board that has a slight foot elevation. But remember, you can lose isolative focus on anything - the floor, a board, or in some other crunch position. It's all dependent upon motion that is unnecessarily into the mix. So ab boards, being narrow, often keep the mind visualizing staying balanced on the board while crunching, so crunching is often executed more carefully than it would be on the floor. There is less room for error, too, because the boards can rock from side to side. So keeping the core absolutely still, while isolating the abs, produces a much tighter effort; literally and figuratively.