I get kneed in the back a lot and my lower back cant take it anymore what is wrong with my back?

I am a flyer on the cheer leading team. When they throw me in the air for a cradle and my stunt group doesn't catch me right and due to that their knees hit my lower back. It is very painful but I never made a big deal about it. Recently it got to the point where I couldn't take it anymore, my lower back feels bruised and hurts when something touches it. I really would rather not see a doctor but I'm wondering what may be wrong with it and how I could help the pain go away. Also, how long the pain will last for.

Your back is not made to take the impact of a fall on a hard knee. The catchers should use a circus hold at shoulder height and move their hands down when contact is made with the falling flyer to absorb the shock over a few feet distance. At no time should the flyer be stopped by a rigid knee.

Talk to the team leader about it. They need to take flying out of the routine until the stunt group gets it right. You can't expect the pain to go away by continuing to do the same thing the same way.