The Plank can be looked on with horror and dislike! I understand this as a teacher because I have seen it performed badly more often than not and that will cause the wrong kind of result. It actually has a very specific set-up to make sure is is successful in working your abdominals rather than straining your back or shoulders. For a beginner it is probably better to start on your knees and build up to the full plank (If you have any knee problems please place a flat cushion