Well crap!

[rockyroad]

Sounds like devdog nailed it - how old are your shoes?? You should look at replacing them...shin and knee pains are quite often caused by the breakdown of the shoe - it doesn't protect your feet from the jarring impacts anymore...try running your hand through the inside of your shoe (let them dry out first of course)...if you can feel indentations from the balls of your feet, then replace the shoes (not just the insert, the shoes)...