A fine golfer came to me in some distress and announced that he could not putt. No way. He couldn't even start the putter back. Since he was about to travel 1,000 miles to play in a competition he felt his situation to be desperate.
I assured him we could remedy the trouble in 10 minutes by eliminating the hands from his stroke.
To do so one putts either with the torso or the hips. One deactivates the hands, clamps the arms firmly to one's sides and moves only the torso in the first instance. Drop the left shoulders (or pull up the right shoulder). Then to make the putt simply raise the left shoulder (or drop the right).
In this case the legs should be kept quite still. But it is also possible actually) to putt with the legs, or as I prefer if the hips.Once again hold the putter firmly, stiffen the arms, then sift the hips, first to the right then back to the left. Arms, hands, and torso move back, and forth all-of-a-piece. The hands are kept out of the act.
This is quite a useful way to putt even for those with steady, sure hands. The golfer I spoke of won his competition and now putts with the big m uscles all the time.