Aha, I remembered something about tennis and thought "Achilles' tendon". Torn calf, that is big ouchie. Almost Henke Larsson-level bad. Don't know how I've avoided stuff like that, the life I led in my youth. Worst sports-adjacent injury I ever caused myself was downhill skiing, freestyling and showing off. I spot a jump someone's made with snow and think "Hey ho - let's go!" and while airborne realise that I should have checked where I was going to land. A tree stump sticking out of the slope. One ski snags the stump and pulls my hip joint alomst all the way out of the socket, then I fall and it pops back. And everything turns a whiter shade of pale, even the snow. Then I slide on my face all the way down to the ski lift. Very gracefully, I'm sure.