A control arm functions as a support beam that help keep the wheels of a vehicle from losing stability. It connects under the chassis, to the hub of a vehicle, using special bushing at its joints, which help absorb vibrations from the road.
The design of a control arm varies according to the vehicle upon which it is mounted. There are also aftermarket controls arms available to help increase the overall stability of a vehicle.
Aftermarket units are built from thicker metals and also use polyurethane bushings. The polyurethane bushings help lessen any noise or vibrations transmitted from the road to the chassis of the vehicle.