Hey :) How to calculate for example knee load during running?

Sorry for my English.

Hi There,
There is no straight way to calculate the knee joint load while running.
You need either to implant a transducer in the joint or measure the force on a special plate and do calculation that are dependent upon the tibia placement etc.
To read a little more about way to do it you can read this article which will give you an idea.
http://www.jbiomech.com/article/S0021-9290(06)00007-8/abstract
Guy

Thank you so much for your reply :)