Thursday, 19 June 2014

Driving Distance in Golf


IMPROVING YOUR DRIVING DISTANCE
Brandon Kowalick
2109590
HLPE3531

The golf swing is an extremely complex sequential state of movements that come together to strike the golf ball in any given direction. An athlete’s golf swing can have major technical differences from each other, but still produce a similar result. Even with the major technical differences present in many golf swings (both at amateur and professional level) the biomechanical principles needed for the intended outcome are still the same. The main biomechanical principles in play are: angular velocity, velocity, newtons three laws, summation of forces, and the kinetic chain (Hume, P, Keogh, J & Reid, D, 2005). Each principle plays a part in the four step swing phase. Newton’s laws are featured the most throughout the swing, with each law being displayed in a distinct phase of the swing of the club (Hume, P, et al., 2005).
 
 

The golf swing can be broken down into four distinct phases. The four distinct phases are: the address, backswing, downswing and follow-through stages (Hume, P, et al., 2005). The address phase prepares the golfer for their shot. The main aim of the address is to ready the golfer by setting the player in good dynamic and static balance for a successful shot. The grip is also paramount in this stage and there are three to choose from: Vardon overlap grip, interlock grip or the baseball grip. Grip pressure can be strong or weak. During the set up 50-60% of the players weight should be on their back foot, with feet spread at shoulder width apart to give a stable platform to swing from. Knees should have a slight bend, with the trunk of the player flexed at 45 degrees which is the primary spinal angle (Hume, P, et al., 2005). The next phase of the swing is the backswing.
 

The primary aim of the backswing is to provide the base link for the downswings kinetic chain, and to ready the muscles and joints required for generating the necessary power to execute the shot (Hume, P, et al., 2005). The club head should follow a perpendicular line to the toes of the golfer, with the shoulders and hips rotating sufficiently to allow this to happen. This is the phase that begins the flexibility in the technical demands needed to execute a successful shot (Hume, P et al., 2005) The club head speed used to strike the ball powerfully begins its build up in this phase. Preceding the backswing is the downswing.

The primary purpose of the downswing is to return the club head to the ball with the maximum amount of velocity that can be controlled (Hume, P, et al., 2005). The text book swing is described as having a single fixed hub or rotation with a two-lever, one hinge moment arm to impact force on the ball (Nesbit, S & Serrano, M, 2005). The centre of the hub lies at the player’s sternum, and it acts as the centre from which the arm rotates around on a specific plane; this is similar to a biomechanical wheel and axle system. The downswing involves using the arms as a two-lever action. For a right handed golfer the left arm in the important arm as it produces the action along with the wrist with serves as a hinge. During the downswing the left arm provides the plane that the club will follow, and the right arm provides the power in the late stages of the downswing (Hume, P, et al., 2005). The energy build from the summation of forces which is initiated from the legs and hips to the trunk and shoulders to finally the wrists and hands is released.

The follow-through is the final phase of the swing. The primary focus of the follow-through is to decelerate the body and the club head using eccentric muscle contractions. The hands and wrist during the follow through follow the plane of the swing path. The elbow flexion enables the deceleration of the club head and trunk rotation. The goal is to finish in balanced position with the body facing the target, the abdominal obliques activate to help with stability (Hume, P, et al. 2005). This is why not just golfers but all athletes focus on their core strength.

THE QUESTION

All golfers both professional and amateur wish to be able to drive the ball longer off the tee. Through technique adjustments and biomechanical principles it is possible to see how the body can generate more power. How can a golfer increase their driving power to strike the ball further?

·         Are there any additional injury risks?

·         What is more important accuracy or distance?

THE ANSWER

The key for achieving maximum driving distance is reaching maximum club head velocity during the downswing phase. Velocity is the change of position of an object, which encompasses both the speed and direction of the object (Blazevich, A, 2010). If the velocity changes in both direction and speed, it is then going under acceleration. For example, if the golf ball changes direction in the air as it veers to the left it is going under acceleration due to forces acting upon the ball. This is Newton’s first law of inertia.

To help achieve maximum velocity the cocking and uncocking of the wrists is crucial in the downswing phase. The first stage of this involves everything moving sequentially and together as a rigid body around a rigid axis (Cochran, A & Farrally, M, 1994). This type of kinetic chain is a throw like movement pattern. A throw like movement pattern involves the joints involved sequentially moving, one after another (Blazevich, A, 2010). This is present in the swing as the hips and legs move followed by the trunk and shoulders, which then is released by the hands and wrists, creating angular velocity. The timing of the uncocking of the wrist is paramount in the ability to produce great club head speeds (Cochran, A & Farrally, M, 1994). For optimum angular velocity the wrist should remain cocked until the last moment (Hume, P, et al. 2005). This is a debate amongst golf coaches as do they sacrifice control for power. With this movement the control of the swing becomes less predictable. Studies have shown that the releasing of the wrist late does improve distance (Hume, P, et al., 2005). The degree of wrist cocking is one of the biggest variables when assessing the different levels of golfers; the wrist cocking accounts for 60.3% of the total variance in club head velocity between professionals and amateurs (Hume, P, et al., 2005). Affecting the releasing of the wrists is the grip strength that is used.
 
 

Grip strength can be either strong or weak both with their positives and negatives. The stronger the grip strength the ability to release the wrists at the point of impact producing greater speed (Cahalan, T, 1991). The weak grip reduces the amount of hand speed that can be created, but its trajectory is more easily controlled. The stronger grip creates a lower margin for error in the swing as it has a greater chance of hitting an off target shot. The level of expertise should play a factor in the players grip strength.

Newton’s three laws play a large role in the execution of a swing. The first law of inertia refers to the object (golf ball) relying upon a force (golf club) to be able to move. Inertia is the reluctance of the body to change its present state of motion (Blazevich, A, 2010). A product of linear inertia is the moment of inertia which is angular motion. Angular motion is proportional to the objects mass and the distance from the centre of gravity (Hume, P, et al., 2005). The larger the object the harder it is to change its velocity. This is present in the backswing as the golf club is angular and has inertia which is cause by the mas of the club ad its distance from the centre of gravity. The second law of acceleration is shown in the golf swing through the change of momentum when the golf club makes contact with the golf ball. The third law of every action has an equal and opposite reaction is present in the ball striking phase of the golf swing. This is shown through the recoil felt through the club immediately after impact.

Another benefit to releasing the wrists late is its ability to create positive acceleration of the distal segment, at the expense of the negative acceleration of the proximal system (Chu, Y, Sell, T & Lephart, S, 2010). The club head is the distal aspect as the club head is increasing in acceleration. As mentioned earlier the wrist acts as an open hinge system allowing for maximum angular velocity to be reached. The difference between professional and amateur golfers is the added consistency that professionals can generate.  Skill cues are important to help players track their technique to achieve their intended outcome.

HOW WE CAN USE THIS INFORMATION

Increasing the overall driving distance of the player can be attributed to small subtle changes to different aspects of the golf swing. One particular skill cue is during the backswing bringing the golf club past parallel (180 degrees). The trunk rotation that’s adds to the speed and acceleration of the swing is more pronounced when the club is brought back past parallel. Going past parallel creates greater inertia, and can create greater force that can be applied to the ball. This comes with an added risk of injury as low-back pain represents 40 – 50% of all golf related symptoms (Gluck, G, Bendo, J & Spivak, J, 2008). The added rotation also creates greater torque which means that the body has moved from its centre of mass losing its stability. These co inside with the angular velocity of the club and their effect on the principal planes and axis points of the body.
 
 

Moving the body away from the centre of the mass greatly affects the stability of the object (in this case the golfer). To counteract this problem of swinging the club and moving the player too far from their point of stability the player can alter their set-up in before the swing has taken place. As the driver is generally the heaviest club in the bag it is harder to make a change in its motion due to its heavier mass. Therefore, in the address phase of the swing instead of having a stance that is shoulder width apart the player should slightly increase the between their feet. The added stability can create a better platform for the golfer to launch from, whilst still staying in their zone of their centre of mass.

To help with the release of the wrists at the point of impact the golfer should look to practice pitch shots that require height. The pitch shot pronounces the snap of the wrists just before impact due to the difference in the club head. The club head is much more lofted, and lighter than that of a driver. This difference can help younger golfers especially as they might not have the physical strength yet to be able to control their wrist action with a heavier club. In conjunction with the wrist action comes the grip strength. To help the golfer grip the club stronger a smaller grip and/or shaft of the club can be employed. This will help with players grip as the smaller grip makes them grip the club tighter as without it the club will become very difficult to control, even making them drop the club. 

The key for driving distance is the cocking and uncocking of the wist during the down swing phase. There are small skill cues which can help accentuate the feelings required. However, the player must decide whether striving for power is worth the sacrifice of accuracy and the increased risk of back injury.  

 
 
REFERENCES

Blazevich, A. (2010). Sports biomechanics the basics: Optimising human performance. A&C Black.

Cahalan, T. (1991). Biomechanics of the Golf Swing in Players with Pathologic Conditions of the Forearm, Wrist and Hand. Journal of Sport Medicine. 19 (3) pp. 288-293

Cochran, A. & Farrally, M. (1994). Science and Golf II: Proceedings of the World Scientific Congress of Golf. Taylor & Francis

Chu, Y., Sell, T. & Lephart, S. (2010). The relationship between biomechanical variables and driving performance during the golf swing. Journal of Sport Sciences. 28 (11) pp. 1251-1259

Gluck, G., Bendo, J. & Spivak, J. (2008). The lumbar spine and low back pain in golf: a literature review of swing biomechanics and injury prevention. The Spine Journal. 8 pp. 778-788

Hume, J., Keogh, J. & Reid, D. (2005). The Role of Biomechanics in Maximising Distance and Accuracy of Golf Shots. Sports Medicine. 35 (5) pp. 429-449

Nesbit, S. & Serrano, M. (2005). Work and Power Analysis of the Golf Swing. Journal of Sport Science and Medicine. 4 pp. 520-533