Tension will destroy any fluidity and smoothness in your swing and make your rhythm, tempo and timing very inconsistent. Remember to “Swing em’ and fling em’. And what I mean by that is to let your arms “swing” and let your shoulder “fling” your arms. They work together. Notice a beginning golfer and how they are all tense in the arms when trying to “hit” a ball. Where as the accomplished player not only “flings” the arms back and up by rotating those larger shoulder, chest and upper back muscles, they also swing their supple arms in conjunction with the upper body rotation.
Being tension free has a numerous positive effects for your swing. One benefit is extension. Notice the word “extension”, take away the “ex” and all you have remaining is “tension”. If you “ex” the “tension” you get “extension”.
Imagine hanging soft ship rope from your shoulders. If you rotated your upper body back and through, the ropes would extend as far as possible from the center of the swing. In your back swing don’t try to keep your left arm (right-handed player) straight; however, keep it extended instead by being supple in those “ropes”. That extension gives you arc width, which generates swing speed, an effect all long hitters benefit from. Rotating creates centrifugal force. Being tense will reduce any built up centrifugal force your rotation has produced. Too much tension will also inhibit a proper release of the forearms, hands and club head. Let’s go back to that rope analogy. Imagine ropes are hanging from your shoulders and the hanging ends of the rope are tied into a knot. The knot represents your grip. In the forward swing the knot would turn counter clockwise following the rotation of your upper body and your arms swinging down and forward. That counter clockwise turn of the knot would represent your grip. Another words, your right hand would turn over your left hand producing a clubface that went from open (pre-impact) to square (at impact) to closed (post-impact) in the forward swing.
Countless students that I have worked with on this have told me that they feel as though they have no control. That is good because they are now swinging the club instead of hitting at a ball. They are transforming a feeling into their swing that they are now getting out of their own way. Pay attention to your tension and you too will gain control by letting go of your so called control.