They usually have rubber wheels made for rugged trails, and hand brakes to help you keep in control of the stroller. (mommystroller.com)
It will make sure you don't lose control of the stroller in case the handle bar slips out of your hands. (momsstrollerreviews.com)
You can also maintain control of the stroller when you are walking on a downhill slope while other strollers would be difficult to control. (mommystroller.com)