Golf: a gentle game that leads to pain

Madelene Sagstrom hits her approach shot on the 18th fairway during the final round of the U.S. Women’s Open Championship golf tournament at Shoal Creek. Credit: John David Mercer-USA TODAY Sports

The leisurely nature of golf makes it popular with older adults who may be unwilling or unable to take up a more punishing sport, where the risks of injury are perceived as much greater. However, the amount of physical activity required to play golf is still sufficient to provide health benefits.

Surprisingly, however, the reality of golf and injury risk is somewhat different. While a properly executed golf swing may not appear particularly stressful, a number of biomechanical studies have demonstrated that many joints and limbs are actually moving at high velocity and through extreme ranges of motion (ROM), making them vulnerable to injury⁽¹⁾. To make matters worse, the successful execution of the golf swing requires a high degree of coordination, requiring many hours of practice during which these powerful movements are repeated hundreds of times. Add the fact that faulty swing mechanics are more likely to lead to an injury and that the golfers with poor swing actions are the most likely to be practicing and you have a recipe for injury.

Prevalence of injury

Putting aside the risks of being struck by a golf club, ball, a golf cart or even lightning, injuries related to golf practice are most likely to afflict the trunk and upper body. Studies show that hand/wrist injuries and elbow injuries are quite common, affecting around 13-20% and 25-30% of amateur golfers respectively. Shoulder injuries are also quite common, affecting around 8-18% of amateur golfers. The corresponding figures for professional golfers tend to be significantly lower^(2,3,4,5).

The incidence of low back pain (LBP) among golfers, by contrast, is rather more common and is known to affect amateurs and professionals alike, regardless of skill level⁽⁶⁾. Epidemiological studies have shown that low back conditions account for approximately 25% of all golf injuries, although incidence rates as high as 54% have been reported^(4,7,8). Moreover, in a 2009 literature review, Cabri and colleagues reported that injury to the lower back represented the most common musculoskeletal complaint experienced by both amateur and professional golf players⁽⁹⁾.

Another study meanwhile surveyed 196 golfers who had just taken up the sport⁽¹⁰⁾. While 25% suffered back pain during the one-year study period, the vast majority of these participants were unaware that playing golf was linked to their LBP. The authors concluded that golf may aggravate pre-existing back pain due to the forceful nature of the movements associated with playing and practicing.

The demands of the swing

To understand how something as apparently benign as golf can lead to a high incidence of lower back pain, it helps to appreciate the biomechanics of the swing (see figure 1). The golf swing involves a slow deliberate rotation of the trunk away from the target (the backswing) followed by a powerful rotation of the trunk towards the target on the downswing. Although there are other spinal motions present during the swing movement, the axial twisting forces are especially noteworthy because this type of twisting has been identified as a significant risk factor for low back injury disorders in occupational settings⁽¹¹⁾.

Studies investigating the axial forces at play during the swing motion have come up with some startling findings. One of the first studies looked at forces on the lower back during a full golf swing while using a five iron – specifically the compressive, shear, lateral bending, and rotational loads on the L3/4 segment of the lumbar spine⁽¹²⁾. Kinetic, kinematic and surface EMG data were collected from four amateur and four pro golfers. Shear loads were high in both groups but were higher in the amateurs, averaging 596 Newtons of force versus 329 Newtons in the pros. Compressive loading, on the other hand, was higher in the pros, averaging nearly 7,600 Newtons versus 6,100 Newtons in the amateurs.

To put these compressive loads in perspective, consider that the swing of a pro golfer generates compressive forces around eight times his/her body weight and that of an amateur around six times their body weight. Now consider that spinal compression forces in a runner are around three times body weight, and you can begin to appreciate the problem. It is also worth noting that cadaveric studies have shown disc prolapse to occur with compressive loads of around 5,500 Newtons, which explains why the swing motion can increase the risk of an acute low back injury⁽¹³⁾. Despite the risk of acute low back injury as a result of the swing, many golfers report the insidious onset of LBP. Insidious LBP is thought to occur as a result of cumulative loading as a result of the combination of large-magnitude spinal forces combined with a high frequency of swing repetitions. Studies show that elite golfers who consistently suffer LBP during golfing activities tend to have a higher frequency of swing repetitions (i.e., spend more time playing and practicing) than symptom-free golfers. Cumulative loading also likely explains why elite players identify overuse rather than a traumatic event as the cause of their LBP⁽¹⁵⁾.

Asymmetry and LBP

As we can see in Figure 1, a relatively slow backswing followed by a powerful downswing and follow-through produces an asymmetrical trunk rotational velocity, leading to differences in spinal loading patterns between the lead and trail sides of the lumbar spine. Indeed, studies show that LBP predominantly occurs on the trail side – i.e., the right side of a right-handed golfer and radiological investigations of elite players have demonstrated a significantly higher rate of trailside vertebral body and facet joint arthritic change than age-matched control subjects⁽⁹⁾.

Other researchers have also noted that both left axial rotation velocity and right side-bending angles on the downswing reached peak values almost simultaneously and just after ball impact, coinciding with the point at which the majority of players in their study report experiencing LBP⁽¹⁵⁾. The implication is that a large amount of side bend angle combined with trunk rotation through the impact phase damages the lumbar spine by creating excessive intervertebral lateral shear. This shearing motion is potentially harmful since it is resisted primarily by disc strength rather than bony architecture, thereby resulting in injury and pain, particularly on the trail side.

One way to reduce lateral shear is to decrease right-side bending (in a righthanded golfer). Studies show that elite players with LBP tend to address the ball with more spinal flexion – i.e., they slouch more and use more side-bend during the swing than healthy golfers⁽¹⁴⁾. The good news for golfers is that decreasing the amount of right side-bend on the downswing may be as simple as using better posture when setting up over the ball. It’s also important to note that the use of shorter clubs encourages right-side bending and that longer clubs may help in this respect.

The ‘X’ factor

In an effort to hit the ball harder and further, many golfers develop a pronounced backswing, which in theory, at least allows more time for the maximal force to be generated before ball contact. More backswing generates higher axial loading in the spine. This is especially the case during the initial stage of the downswing when the pelvis starts rotating towards the target a fraction before the shoulder or acromion line. The idea is to generate the maximum ‘X’ factor stretch – defined as separation in the transverse plane between a line connecting the left and right anterior superior iliac spines and a second line drawn through the acromion processes. A skilled player can increase this ‘X’ factor stretch by as much as 19% during the initial phase of the downswing.

The problem, of course, is that this additional stretch presents even higher loadings to the spine. An over-rotation or supra-maximal twisting of the trunk while performing the golf swing increases the risk of spinal irritation and subsequent LBP. Moreover, many golfers are unable to replicate this degree of rotational stretch in the clinic when asked to do so from a neutral posture at a moderate speed. This has led some researchers to question whether the X-factor loading can be reduced.

One study found that reducing the relative amount of spinal rotation or torsion by increasing the range of hip turn during the backswing could help in cases of golfing-related LBP⁽¹⁶⁾. In another study, researchers questioned whether an extreme backswing was even necessary⁽¹⁷⁾. The researchers investigated the effects of using a shortened backswing on ball contact accuracy and club-head speed. The results showed that restricting the backswing by almost 20% (thereby reducing spinal loading) had no negative effect on overall swing performance.

Together, these and other results have led some researchers to suggest that golfers with LBP adopt a more ‘classic’ golf swing – as used in an earlier era of the game. The classic swing incorporates a reduced X factor, which decreases the torque and subsequent stress on the lumbar spine. This is achieved by allowing the lead heel (i.e., the left heel in a right-handed golfer) to lift during the backswing to allow the pelvis (and not just the shoulders) to turn away from the target.

Core stabilization training suggestions for golfers

Exercises that improve transverse abdominis and multifidus strength and endurance are especially recommended. Of particular importance is ensuring any side-to-side asymmetry is minimized – something that should be emphasized to clients.

Getting to the core of it

Given the role of trunk musculature in generating the swing movement (both downswing and backswing), it’s unsurprising that researchers have investigated whether core muscle dysfunction is implicated in golf-related LBP. Some studies do indeed suggest that golfers with LBP appear to activate their trunk muscles differently to symptom-free golfers, and it’s possible that over time, these differences contribute to reduced trunk muscle strength and endurance.

For example, one study found that the onset times of major bursts of activity from some of the abdominal muscles were delayed in golfers suffering LBP⁽¹⁸⁾. In particular, the lead external oblique (left in right-handed golfers) was activated significantly later during the backswing in the golfers with LBP when compared to asymptomatic controls. Another study looked at EMG activity in the abdominal and trunk muscles of golfers with and without LBP and found that highly skilled players tended to demonstrate reduced erector spinae activity at the top of the backswing and at ball impact⁽¹⁹⁾.

A small number of studies have compared trunk muscle endurance in golfers with and without LBP. For example, one study investigated the total time golfers with and without LBP could maintain an isometric transverse abdominis contraction and found that healthy golfers were able to maintain the static contraction for significantly longer than golfers with LBP^(20,21). This is relevant because transverse abdominis is known to be very important for protecting the lumbar spine by tensioning the thoracolumbar fascia⁽²²⁾.

Another study found that isometric trunk extensor (e.g., erector spinae) holding times for golfers with LBP was significantly lower than values reported from healthy subjects⁽²³⁾, and an Australian study on trainee golf professionals found that golfers with a trailside (ie right side for a right-handed golfer) deficit of 12.5 seconds on the static side plank endurance test reported more frequent episodes of moderate to severe LBP. Further evidence indicates that elite golfers tend to have greater axial rotation strength in the direction they normally swing a golf club (i.e., to the left for a right-handed player) and that this asymmetry or imbalance is likely to be more pronounced in golfers with LBP⁽²⁵⁾. Together, these findings suggest that all golfers, but especially those prone to LBP, should perform some regular core stabilization training exercises.

Box 1: Practical on and off the course suggestions for reducing LBP in golfers

 

In the light of the evidence above, the following suggestions are likely to benefit all golfers, but particularly those who are prone to low back pain: Encourage patients to adopt a common sense approach to play/practice volume; while playing and practising improves performance, players need to be aware of the spinal stresses that golf practice produces and find a balance between participation volume and recovery from LBP. Address asymmetries in trunk musculature/strength between the lead and trail sides produced by high-volume, repetitive practice of golf swings. Perform bilateral strengthening exercise and encourage golfers to take left and righthanded practice swings. Improve trunk rotation flexibility, which helps control the relative over-rotation of the spine during the golf backswing. Explain to golfers the importance of lifting the lead heel at the completion of the backswing, which allows more pelvic rotation, in turn reducing spinal torsion.Improve the strength and endurance of the spinal stability musculature using a variety of core exercises. Work on improving hip rotation and range of movement, especially on the lead side. During the swing, the body pivots onto the lead side; a reduction in the amount of hip rotation on the lead side can cause increased movement and force to be transmitted to the lumbar spine resulting in LBP. Explain the importance of a thorough warm-up prior to playing/practicing and advise patients not to carry golf clubs on their shoulders when playing (push carts are preferable). Last but not least, encourage patients to seek professional assistance from a properly qualified golf coach to assess swing mechanics and determine if there is a need to decrease the amount of spinal side bend on the downswing and through impact. Improving posture over the ball is an example of the way this can be achieved.

Summary and recommendations

When a golfer presents with low back pain, it’s more than likely that the regular practice of his/her sport will be a major contributing factor. In addition to the usual treatment modalities for LBP, it is useful for clinicians to understand how the kinematics of golf can result in LBP and what practical recommendations regarding golf practice can be made to patients in order to speed recovery and reduce the risk of re-injury. Box 1 summarises these recommendations.