By tennis physician, Dr Babette Pluim (@DocPluim)
It was an exciting Australian Open this year, with magnificent tennis, thrilling matches and sizzling heat. The end was a bit unexpected, almost an anti-climax, with Stanislaw Wawrinka seizing the title over an injured Nadal – the first man since 2009 to win a Grand Slam outside the ‘big four’ of Federer, Djokovic, Murray and Nadal.
Nadal’s back problems immediately stirred up debate, with some contending that tennis these days has become so physical that injuries are virtually unavoidable. Is this true? Do we see more injuries now than before?
A recent study by Sell et al. can help us answer this question.  They looked at injury data from the US Open over a 16-year period, from 1994 to 2009, to see if they could decipher a trend. As the US Open is one of the four Grand Slams and like the Australian Open played on hard court and in hot weather conditions, these data may apply to the Australian Open as well.
Their main findings were that there were significant fluctuations in injuries from year to year, but there was only a minor and not a statistically significant upward trend. The ankle, followed by the wrist, knee, foot/toe and shoulder were the most common injury sites. Acute injuries occurred more often than gradual-onset injuries, and muscle and tendon injuries were the most common type of injuries. 15% of all acute injuries involved the trunk, and the overall incidence of lower back injuries was 2.3 per 1000 match exposures.
So the low back is not the most common type of injury, but as we could see in Nadal, quite debilitating. So what caused it? As we could see in the Wawrinka-Nadal match, Rafael had trouble serving.
The strain on the back during serving has been studied by Campbell et al. . The authors compared players with and without low back pain, and found that the players with low back pain had significantly higher lateral flexion forces on the non-dominant side during the driving phase of the serve and both groups had high vertical forces. These forces are approximately eight times those experienced during running. Interestingly enough, both the flat serve and the kick serve created high lumbar loading, challenging the popular perception that only the kick serve is “bad for the back”. This study shows that repetitive, powerful serving places high stress on the back and may result in injury.
The final question is: what type of injury? We do not know the diagnosis in Nadal’s case, but we know what the typical findings are in a large cohort of tennis players. Alyas et al.  studied 33 asymptomatic tennis players (mean age 17.3+/-1.7 yrs) with MRI and found that only 5 (15%) had a normal spine. All the others (85%) had abnormalities in their spine, including pars lesions (9 players), facet arthropathy (23 players) and disc degeneration and bulging (13 players) and synovial cysts (14).
We can look at this two ways: 1) tennis players are at high risk for abnormalities of their lower back and 2) tennis players can be asymptomatic and pain-free, despite abnormalities of their lumbar spine on MRI. Rumour goes that a new study will come out with the findings of 100 asymptomatic tennis players, and I would be really interested to see that study!
As far as Nadal goes I think it is fair to say that it took courage and strength to continue play despite his lower back injury – he fought and lost in style. I wish him a speedy recovery!
- Sell K, Hainline B, Yorio M et al. Injury trend analysis from the US Open Tennis Championships between 1994 and 2009. BJSM 2012 Aug 25 [Epub ahead of print].
- Campbell A, Straker L, O’Sullivan P et al. Lumbar loading in the elite adolescent tennis serve: link to low back pain. Med Sci Sports Exerc 2013;45:1562-8.
- Alyas F, Turner M, Connell D. MRI findings in the lumbar spines of asymptomatic, adolescent, elite tennis players. Br J Sports Med 2007;41:836-41.