Trials: knee and elbow hurting, am I doing it wrong? I just started learning trials stunts. I'm currently playing at a trackstand / wheelie / endo level, so basic stuff.

Yet, my knee and elbow on the lead foot side are hurting... I know quite a few people who have bad knee problems, and I'm a bit worried this may happen to me as well.

Did you experience the same pains when you started trials? What did you do to fight / avoid them, did it go better with practice and muscles, or am I just doing it wrong somehow?

edit, one month later

Just in case some people stumble upon this later, with the same questions in mind...

I've given myself some rest, about two weeks, to let my body recover. Now with more practice, I tend to do smoother moves, and manage to avoid hurting myself.

I also try not to overestimate my capabilities and stop before I'm too tired and something bad inevitably happens.

Always wear a helmet, there are enough videos online to know how it feels like not to wear one.

Wear gloves, they protect your all-important hands. Remember your hands are your first protection when you fall.

I eventually invested in knee protections: my right knee met the pedal a few times, and trust me it hurts badly now. 

Stay reasonably safe and enjoy your stunts :-)
This should be really asked to you physicist, not bicycle related forum.

If you are new to this, this can be "normal", as your bones and ligaments are not used to constant shocks. Do not ignore the pain. Take more time off, if needed.

This is typical problem for runners without previous experience. You can not just start running half-martahons without knee pains which can later lead you to meniscus surgery. You need to start slow and use 10% rule (increase your distance/time per week by no more than 10%).