The unwind occurs as one starts the downswing on a golf swing, or the throwing arm starts to move towards the target. During gait, as the arms are moving apart, there is a winding. The unwinding brings the arms back towards the body. The unwind consists of a combination of two motions, both of which are initially learned and strengthened with pull-ups. The first motion is the pull, and the second is the fly.
Pull
Fly
