Sometimes it makes sense to go against the grain, to do the opposite of what everyone else is doing or what you normally do. It's by no means a novel concept. Seinfeld lovers will recall the episode in which George Costanza did the exact opposite of every one of his instincts and realized it was the way to be successful. This philosophy holds true in the gym, particularly when we're talking about the grip you use on the bar. While it may seem weird or unconventional, flipping your grip may be just the thing you need to spark your muscular fire and ignite new growth. After all, doing the opposite worked for George -- he got the girl and landed a job with the Yankees.Every muscle in your body is composed of thousands of muscle fibers, but they don't all work together simultaneously to contract the entire muscle. Take the biceps brachii, for example. It's actually composed of two heads; the long head sits more toward the outside of the arm while the short head sits right next to it on the inside of the arm. When you do a biceps curl, both heads contract to flex the arm, but some curls cause more of the short-head muscle fibers to contract while other curls cause more of the long-head fibers to contract. Every small change you make in your curls, from the type of bar to the grip you use, changes the muscle fibers utilized in the exercise.To maximize muscle growth, you need to hit all the muscle fibers in a muscle, and the best way to accomplish this is by using a variety of angles, bars and, yes, grips. One simple way to change your grip is to flip it 180 degrees, so that it's the reverse of the usual way you do the exercise. For example, on the bench press you normally grip the bar with an overhand grip. To stress different muscle fibers in the pecs, turn your wrists 180 degrees and do a reverse-grip bench press. You can turn things around with almost any upper-body exercise to significantly alter the way the muscles are targeted.Try incorporating the following reverse-grip moves into your workouts to fast-forward your muscle growth.