The intensive training given to young elite tennis players damages their spines, shows research published ahead of print in the British Journal of Sports Medicine.
Magnetic resonance imaging (MRI) scans of young elite tennis players with no symptoms of pain showed a variety of spinal abnormalities in the lower back, some of which were irreparable.
The scans picked up problems in 28 of the 33 players scanned. All the players were aged between 16 and 23 and were attending a national tennis centre.
The abnormalities included spinal disc degeneration, herniated discs, complete fractures, and stress fractures known as pars lesions. Three of the 10 pars lesions in nine players were complete fractures.
Twenty three players had early signs of diseased facet joint (arthropathy), causing moderate permanent degeneration in nine of them. Facet joints help the spine bend backwards.
At 70%, the rate of facet joint arthropathy was four to five times higher than that of the general population.
Twenty players had signs of skin hardening, and 24 had bone overgrowth, while cysts in the lubricating (synovial) joint fluid were found in 10 players.
The spinal discs of 13 players were drying out due to insufficient lubrication and were bulging in another 13.
The authors point out that the chances of success as a professional player on the circuit are linked to junior career performance, and young athletes spend increasing amounts of time playing and training.
Intensive training during the growth spurt years is linked to injury and musculoskeletal problems, they add. Injuries to the trunk are the third most common type after arm and leg injuries among tennis players.
Tennis requires considerably more repetitive and rapid rotation and stretching of the lower spine than other sports, say the authors.
And the increased speed and types of strokes used in modern tennis all boost wear and tear on the lower back.
Training techniques should be modified to minimise the risk of progressive musculoskeletal damage, conclude the authors.