As a golfer, you may wonder why you would want to resist rotation when your sport requires so much. It appears to be counterproductive, doesn't it? However, training for anti-rotation is essential whether you want to improve your clubhead speed, reduce your risk of injury in the lower back, or increase your strength and tone in the core muscles.
Anti-rotation training allows golfers to transfer force more efficiently from the ground up through the body to the club head. Recent research has shown that the ground is our friend in golf yet again. For example, a study found that the greater the peak force a golfer can apply to the ground during an isometric mid-thigh pull, the greater the clubhead velocity is likely to be. This information is important when analyzing force transfer through the body during the golf swing. If you're generating high ground reaction forces, you don't want any of them leaking out of the system unnecessarily just because you didn't do the proper training in the gym!
Many of you have probably heard the terms kinetic chain and kinematic sequence. For those unfamiliar with these terms, they refer to the sequential transfer of force and movements from the ground upwards, through the pelvis, trunk, and arms, and finally ending up with as much speed in the club head as it travels through impact with the golf ball. It's as easy as whipping a whip! Accelerate one section, then rapidly slow it down to transfer energy to the next segment until the sequence ends with maximum angular velocity.
However, what may be more important than generating ground reaction forces is preventing leaks higher up the chain - so, between the pelvis reaching top speed and the trunk taking over, we need the ability to transfer this force through rapid deceleration of the pelvis. Then, just as we want the arms to take over, the trunk must rapidly decelerate, and so on, until we crack the whip - the clubhead impacting with the ball.
So, while it may appear counterintuitive to train to resist rotation, doing so allows golfers to increase the strength of the muscles that generate rotation and deceleration in their swing.