Front sore legs especially thighs?

Ok, here goes, Ive had had pain in my legs for the last two months, i gotta admit its driving me crazy cause for no apparent reason they can feel shaky and weak, and when i am keeping busy it seems to not bother me to much. back in the winter I was going aggressivly on the treadmill and pushing myself, I could have damaged something nerves or muscles, have been to the doctor, had several tests done, (stress test, barium swallow, bone density) everything came back ok, my question is, could this be due to my thinking to much about it, or could this be cause I suffer from psoriasis which is spreading down my thighs and buttocks, any sort of help or information would be greatly appreciated esciacially if someone has had or have similar symptons Thanx sorry for making it so long.