Hello. Yesterday, While Skateboarding, I Kicked Off With My Left

Hello. Yesterday, while skateboarding, I kicked off with my left leg and then put my foot back to put it on the board, but instead of my foot landing on the board, it landed behind the board on the ground while in motion, causing me to do a full split. A tendon in the rear right of my thigh feels torn right under my glute and it hurts all the way down the back of my leg. What should I do?