Control arms are connected to the frame or body of a car through flexible rubber bushings, called control arm bushings. This allows a control arm to swing up and down as front wheels roll over bumps and potholes. The outer end of a control arm has a ball joint. In some cars, a ball joint is bolted to or pressed into the control arm and can be replaced separately. In others, a ball joint comes with a control arm as one piece. Control arms have a very important role holding both front wheels on the road. If a control arm is excessively worn, damaged or bent, the vehicle is NOT SAFE to drive.