Stretching can reduce the probability, but inadequate stretching doesn't necessarily cause the injury. Anything that puts sudden stress on the calf muscle can cause it - running, jumping, starts & stops, falls, stepping in a hole, etc. And...bad luck.
This and to go 1 step further. Those who are not in shape who then play sports often, but not always suffer injuries like a Torn archilles.
And when it happens to College, NFL players, etc, its usually because the players are putting such pressure on their archilles, calf muscles, because of their raw explosiveness, athleticism.
Back in the days when I was a Gym Rat doing 180 to 360 spin lay ups, and jumping from just inside the freethrow line to the out of bounds baseline underneath the basket, and based on how explosive I was going to the basket and how I attacked the basket, and twisted, slithered, contorted in mid air, around defenders, on way to basket, and then getting hamnered by players on my way to basket and either getting the foul call, scoring a lay up or dishing a assist, and then coming down on, at awkward ankles, etc, its a miracle I didnt get injuries like a torn archilles, back in those days.
Not trying to toot my horn. Just trying to show how these injuries happen.
The normal, but still in shape players, that dont do extreme things, are often the ones that dont get injured with injuries like Torn Archilles heel.
