knee problems from sitting in front computer?

Can you get knee problems from sitting in front of computer all day?

Is your knee hitting a desk leg or the side of the desk?

When I first started working at a desk I had alot of problems with my sciatic nerve, which goes along the back of your leg and can make your knee ache.

not really, but i tend to like my feet hitting something. so sometimes i kick the computer or a ball around while sitting.