In this stroke, the only body parts that move are the wrists. The forearms, upper arms, shoulders, and back remain motionless.
On the backstroke, the muscles on the back of the trailing forearm and the front of the lead forearm contract. The contraction causes the wrists to cock so that the club moves away from the ball. The reverse happens on the forward stroke; the muscles on the front of the trailing forearm and the back of the lead forearm contract, causing the wrists to propel the club forward toward the hole.
To get a sense of what happens when only the wrists move, hold your forearms tight against your body. This immobilizes the forearms, so the only movement is the cocking and uncocking of the wrists. Note that holding the forearms tight to the body is a practice useful only to get a sense of the movement. The actual execution requires the forearms to be away from the body.
The diagrams below illustrate the stroke. The triangle is formed by the arms and the line between the shoulder sockets. In the back swing and forward swing and at impact, the arms and the shoulder socket do not move.
This putting style was popular in the 1950s and 1960s.
Here is an assessment of this putting stroke in terms of the criteria discussed above.
Four muscle groups are involved - the muscles at the front and back of the forearm on both arms.
The stroke engages muscles groups in both forearms. The muscle groups operate in a coordinated way. The actions of muscle groups are restricted because both hands are holding the putter.
To ensure the same muscle groups in both forearms are used, the putter should be gripped with the palms facing each other and the thumbs on top of the shaft. This will ensure that the muscles that pull the back of the hand away from the body centre, and the muscles that pull the palm of the hand toward the body centre, are used.
The wrist joint can move in a variety of ways - up, down, left, right and directions in between. As a consequence, the joint's movement taken alone does not guarantee consistency.
The muscles involved in moving the wrists are relatively small. Their purpose is to carry out the precise movements required by the wrists.
With a wrist stroke, the only mass being moved is the putter. There are no other body parts that need to be moved.
Since only the wrists move, the eye sockets remain still.
The axis of rotation is perpendicular to the forearms. The contraction of the muscles in the front and back of the forearms causes the wrists to move around the forearm at the wrist joint. When the forearms are perpendicular to the ground, the rotation plane is vertical to the ground. When the player assumes a posture with a forward lean and lets the arms hang, the arms including the forearms will hang straight down and vertical to the ground. When the player uses only the muscles in the front and back of the forearms and the forearms are aligned to the target, the stroke will go straight back and straight forward toward the target.
At a maximum the rotation circle radius will be the length of the putter. The maximum circle radius will occur when the putter is a straight extension of the forearms. In most cases, there will be an angle between the arms and the club. This angle will reduce the radius of the circle followed by the putter head. Note that the plane of this smaller circle will continue to be vertical to the ground. The smaller the rotation radius, the greater will be the lift of the putter head on the back stroke and forward stroke.
Since only the wrist joints are moving in the wrist stroke, the rotation centre, which occurs at the wrist joints, is steady.
Essential features of the stroke include a forward lead and arms hanging straight down from the shoulder sockets. With the forward lean, the head and eye sockets will be further away from the body than the shoulder sockets. The distance will be greater with a greater forward lean. The eyes will only be over the ball if there is an appropriate angle between the arms and the putter. The greater the angle between the arms and the putter, the smaller the rotation circle.
The wrists have a limited range of motion. A muscle contraction on the palm side of the forearm can only rotate the hand about 45 degrees from a neutral initial position. A muscle contraction on the back of hand side of the forearm can only rotate the hand about 45 degrees from a neutral initial position. With a 33 inch putter, the maximum backstroke would be about 26 inches.
This wrist stroke does not necessitate a great deal of forward lean, and consequently, should not place undue strains on the back.
Here are some ideas for the performance of the wrist stroke:
The strength of the properly executed wrist stroke is the vertical plane of its rotation. This will get the putts moving on line. The primary weakness is the limits to the power that can be generated through the stroke.