Back f'ing knee

anyone that has seen my videos knows what im talking bout, and its really frustrating me, it always does it, dm can explain what happens cause i dont really know how to put it in words, its almost like it collapses, my new video shows me turning my back foot over jus before foot plant but it still does it, i need to know how to fix this because i think its hurting my control and velocity

See my comment in your video thread.