The benchpress will build powerful chest, shoulder and triceps muscles. For emphasis on the chest muscles, use a grip slightly wider than shoulder width, or even wider. To avoid shoulder injuries, keep your elbows pointing slightly downward towards your feet, rather than flared out to the sides. To avoid wrist/Carpel Tunnel problems, be sure to wrap your thumbs around the bar, rather than using a thumbless grip. It really does make a difference with the angle of your wrists, try it and see! Lower the weight slowly, (about 5 seconds down) then press powerfully back up to just short of lockout. Do not lockout the elbows, as this will remove the stress from the working muscles. For safety sake, always use a spotter when working near failure on the benchpress. To shift the emphasis from your chest to your triceps, use a grip inside shoulder width and keep your elbows close to your sides. I like to turn these into a decline exercise when using a Smith Machine, by putting my feet up on the bench and raising my butt off the bench. This places much more stress on the triceps. Just be sure you have a very stable bench and you are able to keep your body securely in the center of the bench.  Otherwise, it is always better to keep both feet flat on the floor. When using very heavy weights, keep both feet on the floor for sure!
dan4fitness