In general, pro squash players seam not to have joints, ligaments and tendons, the brutal forces and weights they put on them is just out of the reasonably conceivable. Probably the most flexible and the quickest of all of them is rubber-man Gregory Gaultier. Have a look at that incredible get in the left back corner at 0:14, he was down in a split, lost in between his racket, then picked it up with the left hand, passed it onto the right hand whilst standing up quickly enough to get to the opposite corner in the front, just to being sent back again to the back corner. Absolutely hilarious. I'm not sure there is any other sport that requires that much dynamism and athleticism. Let's don't forget to mention how beautifully Adrian Grant was playing his last three shots. First one would already have been a winner against many players; he did so well not to panic for the drop and at last played another perfect length. Observe the early racket-preparation and the extended hold he employed for the last two drives.
