There is almost no chance a schoolboy cricketer, who is a talented fast bowler, will ever play for his country because he will probably injure his back bowling too many balls too young.
Sports scientist Tim Noakes made this observation in an interview recently. He said his experience was that the majority of good schoolboy fast bowlers were over-bowled while at school.
"They are the guys who win matches, yet so little thought is given to their long-term future in the game. It is simply assumed more fast bowling at a young age will make them better adult players. We have no evidence that this is the case and much evidence to suggest the opposite."
Already the careers of some of the country's most promising schoolboy fast bowlers had ended when their backs were damaged in school cricket matches, he said.
"A good fast bowler can easily be made to bowl the whole innings, but I say a teenager shouldn't bowl more than six to eight overs in a spell if he wants to protect his back."
Another alternative was for a schoolboy is to focus on spin bowling, which was safer, and leave fast bowling for later when his body was fully developed, Noakes said.
These observations are being validated in research undertaken by University of Cape Town masters student Janine Gray, who is assessing the long-term effects of fast bowling on the spines of 45 Cape Town schoolboys.
"It's the most intensive research ever undertaken on the subject in the country and, at the end, we should have a clearer understanding of how this sport should be coached
at school," added Noakes.
The cricketers, all between 14 and 18 and drawn from all race groups, have already been put through Gray's first round of tests at the Sports Science Institute in Newlands.
Reflector markers were attached to different parts of their bodies so their bowling action could be filmed by high speed cameras. The information was fed directly into a computer and was now being processed.
"Of the boys we tested, 30% said they had already suffered back pain - an astonishingly high figure, considering they are not out their teens yet," said Gray.
The cricketers most likely to suffer were generally the best bowlers, she said, because of their mixed-action technique which tended to allow them to bowl faster but at greater risk of injury. These bowlers also tended to be over-bowled by their coaches and captains.
Front-on bowlers could also be at risk if they were not adequately physically prepared, she said.
The safest technique was side-on bowling - South African cricketer Shaun Pollock's bowling is a classic example of this style.
"Why mixed-action bowling is so dangerous is that at the moment the cricketer goes into the bowling action he is leaning back, twisting and bending sideways.
"If you do this repeatedly to an immature spine you will cause damage," she said.
When a fast bowler lands, his front leg takes an impact four to six times his average body weight - which again will damage a soft spine if it's done repeatedly.
Most boys bowl an average of 10 overs a game in a one day match (60 balls), and as many as 25 overs (300 balls) in a club match over a few days.
If a boy has lower back problems, Gray says, he must receive prompt medical attention. Rest may be necessary followed by an intensive rehabilitation programme and a slow re-introduction to the game.
The only way to stop the high level of injuries is through careful and informed coaching.
"When a boy complains of a tired back, let him rest, don't send him out for another hour under the pretext of getting him fit."
Gray will deliver her first paper on the research at a conference next month. Already she is travelling around the county with exercise scientist Dr Richard Stretch, from the University of Port Elizabeth, lecturing to cricket unions on safe coaching for schoolboys.
"We can't get to everybody, but we hope by starting at the top, the information will filter down to coaches and parents at school. If we want our boys to be great cricketers - without injury - coaches and scientists have to work together."