Hey guys. I decided to start getting back into shape recently. So I got myself a treamill. After about 2 days of using it, I have developed a pain on the outside of my right knee. I dont know what it is as I have never had knee or really any kind sports injury before. I stopped for a few days, which feels like the knee is back to normal. Then when I start I can feel it comming back after only 5 mins. Walking is ok, only when I start running does it get bad.

I have been running outside for football training beforehand and have never had this problem. Mabey the treadmill and/or my shoes? What do you guys think?

Ps: I should say that I run/walk on the mill for about and 90mins at a 9.0% incline a day. I developed that pain after about day 2. Mabey too much?