" The premise of the tunnel concept is this: You have to start a movement (enter the tunnel) in a good position in order to finish the movement (exit the tunnel) in a good position. The tunnel concept forces you to begin your movement assessment at your start position and make sure that you are setting up correctly. "

― , Becoming a Supple Leopard: The Ultimate Guide to Resolving Pain, Preventing Injury, and Optimizing Athletic Performance