If your child bowls fast, there is one injury you should understand properly, and it is almost never mentioned at club level: a lumbar stress fracture. A crack in the bone of the lower spine.

It is not rare in young fast bowlers, and it is rarely bad luck. There are two causes, and they matter equally.

The first is a spike in workload — suddenly loading the body far more than it is conditioned for. Very little through the winter, then eight overs a day at a festival week in June. It isn’t the total that does the damage, it’s the jump. And this can happen to a bowler whose action is perfectly sound; a safe action is not immunity.

Here is the part almost nobody accounts for: the load doesn’t only come from bowling. If your child also plays tennis, throws the javelin or discus at athletics, plays hockey, squash or badminton, or plays golf, the spine is absorbing the same kind of ballistic rotational load from a different direction. Rugby is a different matter again — not rotational in the same way, but a serious load on a growing spine right through the winter. Parents and coaches count overs. Nobody counts the total. A talented multi-sport athlete can be doing everything asked of them in each individual sport and still be carrying a workload no one has added up — which is exactly how the most athletic children in a squad end up injured first.

The second cause is mechanical, and it is the one nobody mentions: a fault that is visible on a phone camera months or years before anything hurts. Where the action is dangerous, a bowler is at risk at almost any workload — and the two causes compound, because a spike in workload through a faulty action is the worst combination there is.

What the mechanical fault actually is

The mechanism is rotation combined with sideways bending of the trunk under load. In coaching terms, lateral flexion.

Here is what it looks like. Between front foot landing and the ball leaving the hand, the head and shoulders drift to one side — for a right-armer, usually towards the off side. The trunk bends laterally. Instead of driving the chest straight over a braced front leg and down the pitch, the bowler collapses sideways around it.

Do that once and nothing happens. Do it four hundred times a week through a winter, while the spine is still developing, and the same small section of vertebra is loaded asymmetrically every single delivery. Bone responds to repeated asymmetric load the way any material does. Eventually it fails.

Why it is missed

It doesn’t show up where people look. At front foot impact the action can look entirely tidy. The bend appears two or three frames later, at release. A coach watching in real time from mid-off sees a bowler bowling quickly and looks no further.

It starts as something that looks harmless. Before the trunk bends, the head falls away. A small drift, easy to dismiss. But the head falling away before front foot contact is not a separate quirk — it is the beginning of the bend. By release it has become the full thing.

It often comes with pace. A bowler who falls sideways is frequently the quickest at the club, because they are generating force, just not sending it down the pitch. Nobody wants to interfere with the fast one. So it gets left, and it gets grooved, and then it gets diagnosed.

How to check, this weekend

You need a phone and a straight view from directly behind the bowler, roughly stump height.

Find the frame where the front foot lands. Note the angle of the torso. Now step forward two or three frames, to the moment the ball leaves the hand, and look at the torso again.

If it has tilted noticeably sideways — if the head is now well outside the line of the front foot, if there is a pronounced lean away from the target — that is lateral flexion, and it is worth acting on now rather than after the first back complaint.

While you’re there, check two related things. Does the back foot drag along the ground until the ball has gone, or lift away early? Early lift disengages the hip flexors and is one of the common causes of the sideways collapse. And is the front leg braced straight at release, or still bending? A collapsing front leg gives the body nothing to drive against, so it goes around the side instead.

The part parents find surprising

The instinct, once you know a back injury is possible, is to protect: bowl less, land softer, ease off.

Managing volume is genuinely important — build it gradually, avoid sudden jumps, count the load from every sport rather than just the overs, and take pain seriously. But it isn’t the whole answer, because reducing the volume of a mechanically dangerous action leaves you with a mechanically dangerous action performed less often. The fault is still there, waiting for the first busy week.

And softening the landing frequently makes it worse. A braced, straight front leg is what allows the body to drive forward, over the top and down the pitch. Take the brace away and the body has nothing to work against — so it does what it always does when it can’t go forward. It goes sideways. The thing that feels protective produces the exact loading pattern you were trying to avoid.

The fix is not simply less bowling. It is a correct sequence: base firms, hips drive, chest follows, arm last. Get the hips driving the torso rather than the torso dragging the hips, and the sideways collapse has no reason to exist.

When to get it looked at properly

Any lower back pain in a young fast bowler should be treated seriously and assessed medically. Not stretched off, not bowled through, not left until the end of the season. Early stress reactions respond well to being caught early and badly to being ignored.

And before that point — if you’ve filmed them and you’re not sure what you’re looking at, send us the footage. Assessing this is precisely what a video trial is for, and we would far rather tell you a young bowler’s action is safe than see them arrive with a diagnosis.

Ian Pont is Director of Cricket at the National Fast Bowling Academy and has coached fast bowlers at international level. This article is general coaching guidance and not medical advice — if your child has back pain, see a doctor or physiotherapist.