*4.1.3 Circular motion of a golf swing*

Unlike other ball hitting sports such as cricket, hurling, tennis and baseball the golf swing is a circular motion attacking a stationary object, the golf ball.

The circular motion is subject to other physic parameters:


#### *4.1.3.1 The double pendulum effect*

A physical pendulum is a solid object that swings back and forth on a pivot under the influence of gravity. The golfer has 2 anchors, the shoulder and the wrists. In a golf swing, the connection between arms and club creates a double pendulum effect. The arms make up one pendulum that pivots around the shoulders, while the club makes a second pendulum that pivots around the wrists, which acts as the pivot. The two pendulums can swing independently but work together to make the swing feel effortless.

### *4.1.3.2 Centripetal force*

Centripetal Force is a force that makes an object move in a curved motion, like a rollercoaster hugging the curve around a loop. The golf club swinging in an arc from the shoulder to the ball. The hands hold the club and prevent it flying off in a straight line, in a centrifugal fashion. In essence the golfer pulls the wrists and club handle inward while swinging the golf club and golf head outward.

The faster the club curves and the bigger the arc in a golf swing (radius) the greater the force of the club on the ball, and the farther the golfer should be able to hit the ball.

$$\text{Centripetal Force} \coloneqq \text{mass} \times \text{velocity}^2 / \text{radius}.\tag{3}$$

<sup>2</sup> Centripetal Force =weight of club swing sp × eed /swing arc. (4)

The mass and velocity are also a function of gravity.

*Leading Wrist Injuries in a Golfing Population. Golf Swing Biomechanics a Significant Cause… DOI: http://dx.doi.org/10.5772/intechopen.96979*

#### *4.1.3.3 Torque*

In physics Torque is a measure of the force that can cause an object to rotate about an axis. It is a rotating force in a circular motion as opposed to a simple force which causes an object to accelerate linearly. Torque is the force that causes an object to acquire angular acceleration in a golf swing.

Torque is the rotating force in circular motion as you swing back, coiling your body, and then start the downswing. This creates the stored or potential energy at the top of the swing. If you hold the club and prevent it releasing on the down swing you increase this stored energy. The hands and wrists are resisting the angular acceleration of the golf club. Increased torque and stored energy are ultimately released by the club face at the bottom of the swing.

Torque = Force distance × *.* (5)

These elements of classical physics have fascinated golfers who seek greater distance in their golf shots. The mass dynamics and weight of golf clubs and their structure are subject to the rules of golf (1) and can be considered a constant. Velocity is the variable element.

Golfers have pondered on this singular element for centuries. Swinging faster or manipulating the club in the down swing through releasing the club later will add greater speed. Similarly firing the right side of the body or manipulating the club face through the hands remain the other options available to the golfer seeking greater distance. Each augmentation compromises the leading wrist and are associated with injury.
