Another thing is the gate. If your gait is off you can develop problems with the way you walk. This can put extra strain on the way you walk. If your hamstrings are tight, then it can throw your gait off. Even calves being too tight can throw off your gate.
Tight calves can lead to tendonitis of the patellar tendon.
Same as overpronation, which is walking too much on the inside of your feet. A 14 degree angle deviation or more is bad. I cannot really describe the Q-angle, because you really need someone who knows what they are doing to perform it. This is very true. Always make sure when you use a machine or free weights, that you knees never ever go past your toes.