Since hitting of the ball may be repeated an average of 50 times during an 18-hole course, or 300 times or more during a practice session by a professional, it is easy to understand that, for both professional and recreational players, injuries can occur either through overuse or bad technique through actions causing severe trauma (Kohn 1996).
McCaroll (1990) found that professionals injured their self less frequently than that of amateurs, and that the causes of injury were due to poor swing mechanics.
Injuries to these musculoskeletal structures are caused either by overload of tension, twisting of the tissues or the strain of the physical impact of hitting the ball (Stover 1976).
The aim of this essay is to review and analyse the golf swing biomechanically to identify the correct technique to help prevent common golfing injuries. The golf swing will be broken down in to 6 phases; ball address, end of backswing, forward swing/acceleration, ball impact, early follow through, and late follow through. For each of these 6 phases the human body undergoes biomechanical stresses likely to provoke injuries, these injuries and their prevention will be discussed during each phase.
Phase 1 and 2 – Ball Address and End of Back Swing
There are several factors to consider during the ball address to ensure an effective technique for force production and injury prevention.
Bad posture can cause skeletal and joint misalignment, which will affect the pattern of stress imposed on tissue and the area of force distribution (McGinnis 1999). Therefore if the player’s posture is less then optimal they begin and end movement in an aberrant position and as a result the chances of accelerating joint wear are increased.
The attainment of the optimal pre-stroke posture is achieved through a good starting position – i.e. even weight distribution on both feet with a shoulder width stance. This will ensure a significant base of support that will promote stability and equilibrium to the golfer as the centre of gravity moves throughout the shot. Therefore allowing maximal potential kinetic energy to be generated through the club. If the stance is too wide truck rotation will be reduced placing greater strain on the spine, causing injury. Alternatively, if the feet are too narrow, reducing the base of support, it could lead the golfer to lose control of the swing due to a decrease in stability. To help prevent injuries to lower back during the entire swing it is essential to have good core stability. (Wilson 2005 p. 316) describes the core “as the ability of the lumbo-pelvic hip complex to prevent buckling of the vertebral column and return it to equilibrium following perturbation”. As a result, core stability is essential to help stabilise the body which in effect will help to support the antagonist of the abdominal, therefore preventing injury to the lower back. As joint mechanics are less than ideal with poor posture, joints will not effectively move around a central axis, therefore preventing angular motion. With poor posture, the stabilising muscles of the body (those that help maintain joint axis rotation), become long and weak. In opposition, the movement muscles of the body become overused, short and tight. A continuation of this cycle leads to further imbalance, increasing the chances of injury (Chek 1998). Once good posture is achieved there should be slight anterior flexion of the trunk at the hips and the shoulders, knees and feet must be aligned. The back must be kept straight while keeping the vertebral column perpendicular to the ground in the frontal plane (although the upper body of the player remains leaning forward towards the ball to allow a lower centre of gravity to optimise equilibrium throughout the swing).
If your centre of gravity is not distributed evenly when you take your setup due to a postural fault or incorrect stance the centre of gravity may be too far back, which in effect will cause the legs to move before the backswing is complete. Consequently power is supplied by the arms and shoulders only, which again creates excessive force through the shoulder and elbow.
In the second phase, the backswing, a simultaneous rotation to the right side around the spinal vertical axis of the knees, hips and upper limbs is executed. This raises the club to its highest point in order to obtain the widest possible arc of motion (Adlington 1996)
Injuries related with the address and backswing of the golf swing are:
Frontal flexion at the dorsolumbar spine rather than at the hips increases the possibility of vertebral hypermobility and unbalanced muscular stress during the backswing (Hosea 1996)
Overextended, straight arms (especially the left) or hyperextend elbows and abnormally high muscular tension in the forearms (too tight a grip) reduces the effectiveness in creating speed in the downswing and can induce elbow and wrist injuries at ball impact (Gosheger 2003)
A grip without interlocking hands or too loose a grip increases the danger of dropping the club causing a loss of accuracy on ball impact and injury of the elbow, wrist or hand through ground impact.
An excessively long backswing may cause trunk over-rotation injury or throw the golfer off balance leading to ground collision injuries.
Excess backswing also increases tension in the left thumb and right wrist. Excess arm/shoulder elevation on the backswing, with the left arm abducting the left shoulder, impinges on the subacromial tissues (tendons, bursa) and requires good stabilisation from the rotator cuff muscles. If the bursa continues to be impinged this could lead to the bursa becoming inflamed causing bursitis.( Jobe 1996)
Leftward spinal lean, instead of being parallel to the ground, during the rightward weight shift increases the possibility of a conflicting spinal curve posture at the end of the follow through. The rightward weight shift abnormally collected on the outside of the right foot can cause a loss of equilibrium and right ankle sprain.( McCarroll 1990)
Phase 3 and 4 – Forward Swing/Acceleration and Ball Impact
The third phase of the golf swing is characterised by the activation of an anatomical multi lever system which gives the club a downswing in a rotational, angular trajectory and a maximum speed. A lever system is rigid or semi-rigid object that is capable of rotating around a fulcrum (McLeste 2008). In a golf swing a third class lever is present and consists of the golf club and the golfers arm. Levers increase speed and power, therefore maintaining a longer lever will increase power production. If the lever is shortened due to flexing the elbow on impact it will take a greater force to obtain the same power. Therefore excessive force will be transferred into the elbow. If the fulcrum is so far off-set away from centre, a lot of muscular effort must go into the grip of the club at one end in order to move the club head at the other.
These levers are activated in sequence from the ground level upwards; from the feet to the wrists. Prior to the completion of the backswing, good golfers are gathering kinetic energy from the ground upwards in preparation for the downswing. As the feet push into the ground forces are generated and then transferred back into the body, in turn accelerating firstly through the hips, shoulders, arms and then club head. This is an effective use of the kinetic chain by generating forces from the bottom up which will allow for an efficient smooth motion. If the kinetic chain breaks down due to inconsistency in the swing technique this could lead to injuries as the force is not being controlled and distributed evenly through the body.
The risks for injuries in the downswing and ball impact occur in the zones of greatest muscular activity. There is also risk for injury to the elbows, wrists and hands if any of these 3 structures is held too stiff. (Kohn 1996)
Injuries related with the down swing and ball impact of the golf swing are:
Thoracic and abdominal muscular strains may arise after forceful upper body rotation on the downswing. (Stover 1976)
The leftward weight shift can create considerable compressive forces on the left leg (hip, knee, ankle and foot) which are hazardous to individuals with osteoarthritis. (Hahn 1991)
Lateral or medial epicondylitis (golfer’s elbow) can be sustained at impact if the grip is too tight or the elbows are held too tightly or are hyper extended. Grips size is therefore important as too small a grip will make the golfer grip tightly. Clubs of proper weight, length, and grip are therefore important in significantly reducing the vigorous forces generated within the elbow (Kocker 2000)
Excessive wrist flexion/extension in the downswing, or hitting the ground after losing equilibrium, can cause serious hand and wrist injuries. (Murray & Cooney 1996).
Phase 5 and 6 – Follow Through and Late Follow Through
The follow through is essentially the deceleration of the body after contact with the ball has been made. Deceleration by the body occurs as a result of the absorption of energy back up through the kinetic chain of the body. The danger for injuries to the lumbar dorsal zone arises if the deceleration stops too abruptly or if the final range of motion of spinal rotation is too prominent (Parnianpour 1988). Posterior shoulder injuries are most likely during the follow through due to the high inertia and large acceleration (Atwater 1979). At the very top of the follow through, the spine is rotated to the left, and the hips are fully facing the target which enlists the help of the abdominal muscles to support the spine, while the wrist joints abduct working the wrist extensors to drop the club behind the back. At impact, the body shifts back to the relatively symmetrical position for a very short time, then the centre of gravity shifts towards the target as the mass of the arms and club move in that direction. To golfer must dissertate and control this energy if he intends to remain on his feet. Research by Fleisig (1995) indicated that at impact the left foot (right-handed golfer) is supporting 80% to 95% of the golfer’s weight, therefore concluding it is essential for golfers to wear spikes to help control this energy. Gatt (1998) supports this theory stating they provide additional traction, allowing the forces generated by the lower body to be transferred into the club.
Injuries associated with the early and late follow through are:
Shoulder ligaments and rotator cuff muscles can experience excessive mechanical stress (tension or compression) in a forceful follow through (Hovis 2002)
Injury to the hips or dorsolumbar spine may arise due to the deceleration of the follow through is too rapid (Parnianpour 1988)
An excessively forceful drive, inducing a reversed C lordotic spinal curvature, may induce unusual high stresses on the dorso-lumbar vertebral bodies, in particular on the posterior joints (Batt 1993)
An off-balance weight transfer or slide can cause an ankle or foot sprain as well as knee injury
Flexible muscles and tendons are extremely important in the prevention of most strain or sprain injuries. It is important to have a significant amount of muscular strength and muscle endurance as this will affect the magnitude of the loading and shock absorption on the body. Joint flexibility will affect the load pattern of segments (McGinnis1999).When muscles and tendons are flexible and supple, they are able to move and perform without being over stretched. If, however, muscles and tendons are tight and stiff, it is quite easy for those muscles and tendons to be pushed beyond their natural range of movement and therefore this will increase the risk of injury. When this happens, strains, sprains, and pulled muscles occur.
In addition for the need for flexibility the following strategies aid to prevent golfing injuries:
sprain, muscular strain, herniated disc and arthrosis (Hosea1996).
Straight back posture, maintaining joint alignment and weight transfer during the golf swing
Speed control during trunk rotation (i.e. use of the kinetic chain)
Reduction of the shoulder range of motion and trunk
Effective use of angular motion
Dorsolumbar conditioning through flexibility and muscular strengthening exercises
Elbow, wrist and hand
Epicondylitis (Golfers Elbow), chronic sprain, tendinitis, carpal tunnel syndrome and fracture (Murry & Cooney 1996)
Reduction of wrist flexor/extensor (grip) tension and loosening of elbows
Reduction of excessive wrist motion
Maintaining good balance during weight transfer
Wrist and finger flexor/extensor conditioning for flexibility and strength
Use of a counter-shock brace, a more flexible, lighter golf club (graphite) or club counter-shock device (Metz 1999)
Tendinitis, bursitis, glenohumeral instability, sprain (Jobe 1996)
Reduction of the angular shoulder displacement at backswing
Control of excessive arm motion at follow through
Conditioning exercises for flexibility (posterior capsule) and rotator cuff strengthening to help stabilise the shoulder joint (Hovis 2002)
In conclusion restrictions in the body in terms of flexibility, muscular strength, endurance, or power can create boundaries in the swing from a biomechanical viewpoint. In addition, biomechanical defects in the swing itself limit the potential and kinetic energy outputs of the body. Injuries to the upper limb account for the majority of golf-related injuries. Most injuries occur as the club impacts the ball and are muscle-related due to the high forces and strain applied during the downswing. An understanding of how the body moves biomechanically to harness these forces and the muscle activity achieved during the golf swing will help athletes and coaches to understand why these injuries occur and the ways to prevent them in the future.