I think most shooters these days do that, but I haven't been paying that much attention. I know the MW games did and I know Counter Strike did it ages ago. --- 2% of GameFAQs users have this in their signature. If you're one of the 98% that doesn't, copy and paste this into your signature.
in Modern Warfare, your movement speed is reduced when your primary weapon is a LMG. In World at War your speed is reduced by certain MG's and the perk 1 bazooka. I'm pretty sure the flamethrower also slowed you down. --- http://m1clan.co.cc (in construction) MWReflex FC: 4994-0070-9017