With the Masters teeing off tomorrow I thought it may be nice to review some of the golfing literature which has relevance to Podiatry. I am a huge golf fan and research which states that 10-20% of the adult population in many countries play golf1 suggests I’m not alone. I enjoy reading about the technicalities of golf almost as much as I do playing it. I think the reason it interests me so much is that it is basically the application of Newtonian physics and concepts such as lever arms and kinetics; things which form part of my own working day when performing gait analysis (and which I’m sure will eventually have their own more detailed blog entry when I get the time).
The golf swing is a highly co-ordinated and individual motion with significant subject to subject variation.2 This blog certainly does not intend to be an all encompassing discussion on swing biomechanics. Instead we will look at a brief summary of the injury statistics, and then some of the lower limb considerations. A right handed golfer is used for all descriptive purposes.
The most common locations for injury are generally reported as being the lower back, and the upper limb (shoulder, elbow and wrist).3,4 Pietrocarlo reported that foot issues can include blistering, Mortons Neuroma, ankle ligament damage and Achilles tendon problems.5 Due to golf being a non-contact sport at least 80% of injuries reported are overuse injuries6 and direct impact trauma is fortunately quite rare. A study in 2003 by Gosheger and colleagues6 found that there was an increase in injury risk for individuals who played 4 rounds or more or hit 200 range balls or more per week. This is likely to be the reason that the incidence of injury is much higher in professional golfers than in amateurs. They also discovered that carrying a golf bag increased the chances of back, shoulder and ankle problems.
And then of course there are what we tend to refer to as ‘aches and pains’. Not specific injuries as such, but musculoskeletal niggles which come on at some point (usually on the back 9). The sore feet I experienced by hole 14 during a recent round of golf I played over Easter got me thinking about how much walking was actually involved. The course was just over 6000 yards in total (about 3.5 miles) and my score of 111 suggests I walked a bit further than that. On average a round of golf takes 3-4 hours and is realistically likely to involve up to 5 miles of walking.
Lower Limb Considerations
The golf swing is considered one of the most difficult biomechanical sporting motions to execute2 and is ideally made up of a good stance, posture and grip. A portion of the swing power is derived from the lower body7 and greater club head velocity (the speed of the club face at time of impact with the ball and the consequent distance the ball will then travel) can be achieved with optimum weight transfer from the back (right) to the front (left) foot during the downswing.8 Therefore it is easy to see that the shoe/ground interface is a vital link that allows a golfer to perform the specialised movements during their swing.9 For those who are not familiar with the golf swing it can be seen below
During the back swing (phase 2) weight shifts to the back foot, and then during the down/forward swing (phase 3) and onwards the weight transfers to the front foot.10,11 In order to maximise the club head velocity at impact (phase 4) considerable ground reaction force must be produced.9 Ground reaction force is essentially how hard the ground pushes up on the foot, which in accordance with Newtons 3rd Law is exactly the same amount of force as the foot pushes down into the ground with. It is well documented that low handicap/professional golfers have significantly higher ground reaction forces and a faster weight transfer to the front foot than high handicap/amateur golfers.12,13
Due to the centrifugal force of the club, the magnitude of these forces is often greater than the golfers body weight.10 Cooper11 found that it was 150% of body weight with a driver, and 133% body weight with a 3-iron. Williams & Cavanagh9 report maximum vertical ground reaction forces of 1.6 times body weight when using a driver. Believe it or not the magnitudes of ground reaction force during a golf swing have been said to be comparable to running at a velocity of 4m/sec.8,14
Finally, we also need to consider torque. This is the tendency of a force to rotate an object – if force is a push or a pull then image torque like a twist. Maximal torque is doubled at the front foot (left) when compared to the back (right) foot.15 Generally there does not appear to be a difference in this torque between clubs, although low handicap golfers do seem to generate increased torque when using the driver.
This should give some indication of the sort of forces at foot level for each golf swing (remember this is on top of that 5 mile walk we mentioned). What should be clear by now is the very different function of the left (front) and right (back) feet during the golf swing. This was highlighted by Williams and Cavanagh9 who discussed the implications this could have on golf shoe design.
Golf and Foot Orthoses
There is not an incredible amount of literature regarding the use of orthoses but what there is seems favourable. Prefabricated (off the shelf) orthoses have been shown to improve the posture of the back (right) foot, and also improve lower limb pain levels.16 However it should be noted that the placebo in this randomised control trial did just as well as the orthoses in improving comfort. Considering the asymmetrical function of the feet which we have just discussed it intuitively seems that orthoses which are symmetrical (such as prefabricated devices) may not be the most beneficial for a golfer.
A study by Stude and Gullickson in 2000 investigated custom made orthoses.17 These had the advantage of the device for the left foot and the right foot being designed independently of each other and bespoke to each golfer. Following 6 weeks of wearing custom made orthoses it was found that club head velocity increased by 7%. In real terms this was equivalent to the golf ball travelling a further 15 yards per shot. It was also found that the orthoses reduced the effects of fatigue associated with 9 holes of golf; and therefore may also improve consistency of performance.
(1) Low handicap and professional golfers tend to suffer with more overuse musculoskeletal injuries than high handicap/amateur golfers despite their superior swing technique. (This is likely due to the increased volume of golf they play and possibly the greater ground reaction forces and torques generated).
(2) Injury risk can be reduced by playing less than 4 rounds a week, and always using a trolley or cart rather than carrying your bag.
(3) Foot orthoses can reduce lower limb fatigue whilst playing, and in some instances may improve club head velocity and therefore increase the distance the ball is hit.
(4) The demands on the left and right feet when performing a golf swing are very different, and this has implications for custom made orthoses prescription.
- Theriault, G. & Lachance, P. (2005). Golf injuries: an overview. Sports Medicine, 26(1), 43-57.
- Nesbit, S.M. (2005). A three dimensional kinematic and kinetic study of the golf swing. Journal of Sports Science & Medicine, 4, 499-519.
- McHardy, A., Pollard, H., & Luo, K. (2006). Golf Injuries: A review of the literature. Sports Medicine, 36(2), 171-187.
- Batt, M.E. (1992). A survey of golf injuries in amateur golfers. British Journal of Sports Medicine, 26(1), 63-65.
- Pietrocarlo, T.A. (1996). Foot & Ankle Considerations in Golf. Clinics in Sports Medicine, 15(1), 129-146.
- Gosheger, G., Liem, D., Ludwig, K., Greshake, O. et al. (2003). Injuries and Overuse syndromes in Golf. American Journal of Sports Medicine, 31(3), 438-443.
- Gatt, C.J., Pavol, M.J., Parker, R.D. et al. (1998). Three dimensional knee joint kinematics during a golf swing: Influences of skill level and footwear. American Journal of Sports Medicine, 26(2), 285-294.
- Hume, P.A., Keogh, J., & Reid, D. (2005). The Role of Biomechanics in maximising distance and accuracy of golf shots. Sports Medicine, 35(5), 429-449.
- Williams, K.R. & Cavanagh, P.R. (1983). The mechanics of foot action during the golf swing and implications for shoe design. Medicine & Science in Sports & Exercise, 15(3), 247-255.
- Carlsoo, S. (1967). A kinetic analysis of the golf swing. Journal of Sports Medicine & Physical Fitness, 7, 80-81.
- Cooper, J.M., Bates, B.T., Bedi, J., & Scheuchenzuber, J. (1974). Kinematic and kinetic analysis of the golf swing. In: Biomechanics IV; Proceedings of the 4th International Seminar. Baltimore: Unoversity Park Press.
- Wallace, E.S., Graham, D. & Bleakley, E.W. (1990). Foot to ground pressure patterns during golf drive: A case study involving a low handicap player and a high handicap player. Science & Golf I; Proceedings of the 1st World Scientific Congress of Golf. London: E+FN Spon, 25-29.
- Koenig, G., Tamres, M., & Mann, R.W. (1994). The biomechanics of the shoe-ground interaction in golf. Science & Golf II; Proceedings of the 1st World Scientific Congress of Golf. London: E+FN Spon, 40-45.
- Nachbauer, W. & Nigg, B.M. (1992). Effects of arch height of the foot on ground reaction force in running. Medicine & Science in Sports & Exercise, 24(11), 1264-1269.
- Worsfold, P., Smith, N.A., & Dyson, R.J. (2008). Low handicap golfers generate more torque at the shoe-natural grass interface when using a driver. Journal of Sports Science & Medicine, 7, 408-414.
- McRitchie, M. & Curran, M.J. (2007). A Randomised Controlled Trial for evaluating over-the-counter orthoses in alleviating pain in amateur golfers. The Foot, 17, 57-64.
- Stude, D.E. & Gullickson, J. (2000). Effects of orthotic intervention and nine holes of simulated golf on club head velocity in experienced golfers. Journal of Manipulative and Physiological Therapeutics, 23(3), 168-174.