The backstroke should be guided by the arms and shoulders in a simple, back-and-forth motion, with minimal wrist action.

Most golfers use a stroke that takes an inside-square-inside path in relation to the target line (like the full swing); here’s how a sound backstroke works:

• Maintaining the V formed by the forearms, wrists and hands, use the arms and shoulders to pull the putter
  back. The wrists should remain locked, but not tense.
• Focus on the back of the ball, keeping the head still.
• The knees, hips and torso should be still as well.
• The length and speed of the putt
  determines how far you take the putter back. The backstroke should be the same length, or slightly shorter than, the follow-through.

For more information on Thomas Golf Putters: