Two of the biggest factors that contribute to distance are hitting the golf ball in the center of the club face, and creating speed. Think of your swing Taylormade Irons as having two engines - your body and your arms. Both are power producers and both have their role in the swing golf irons.The body needs to make a centered turn around your spine with limited up and down or side to side motion, thus creating an efficient coiling of the upper body and lower body. The arms are your second engine and they will swing around your body with speed, but only if they are relaxed.Taylormade R9 TP irons Imagine swinging a string with a rock attached at the end. As your arms swing around in a circle, the rock follows the path of the circle, and continues to increase its speed as your arm increases the speed of the string. In its passive state, the string is limp but when in motion, it stretches out and straightens. For those players who try to keep their arms straight at address or during the swing you are simply losing speed, creating tension, and producing a weaker impact.
Image A: Replicating a baseball swing's extension will help your swing speed. TaylorMade Burner Super Launch Irons