The halftime fan sprint is the most reckless minute in the stadium

Untrained spectators are pulled from a seat and asked for a maximal effort, which is precisely how tendons let go.

Somebody's uncle is about to run forty metres for a prize, and he has been sitting down for an hour and fifteen minutes.

The engagement people love this. It fills a dead slot, it puts a face on the big screen, and it costs almost nothing. What it also does is assemble every risk factor for a soft tissue rupture into a single unrehearsed effort, then broadcast it.

Consider the mechanics of a sprint start for a body that has not sprinted in years. Acceleration is produced largely by the hip extensors and the calf complex, and the hamstring group works hardest not while pushing but while slowing the swinging shin just before the foot lands. That lengthening moment is where hamstrings tear in trained sprinters who have warmed up for forty minutes. Our volunteer has warmed up for zero, in a cool concourse, on legs that have been folded at the knee since kickoff.

The Achilles has a similar problem with a different trigger. A cold tendon is stiffer and less able to spread the load along its length. Push off hard, especially with the knee straight and the ankle snapping through, and the failure tends to be sudden and complete rather than gradual. People describe it as being kicked from behind. Nobody kicked them.

There is a second half to this that irritates me more. These events are usually run on the pitch surround or across a section of turf, in ordinary shoes, with a photographer's cable somewhere and a turn at the end. The turn is worse than the sprint. Changing direction at speed on a slick surface in flat soles is the classic mechanism for a knee ligament, and the participant has no idea that the dangerous part is the cone, not the straight.

I am not arguing for banning fun. I am arguing that the format is chosen badly. A skill contest, a throw, a putt, a target kick from a standing position, all give you the same crowd moment without asking a sedentary adult for a maximal lengthening load with no preparation. Some clubs already do this. Others still run the race because the race looks better on the screen.

The screen is not the one that has to walk to the car park afterwards.