CONTROL ARMS - KEY TO PERFORMANCE
The arm spans out to the spindle or knuckle support. It is connected with a ball joint, or with a pin and bushing. In many applications a control arm works in unison with an upper or lower control arm. This is called a double wishbone suspension.
In recent years, the double wishbone suspension design of control arms is being used far less. In its place, McPherson strut configurations, and multi-link suspension systems have become more common. Wikipedia offers this additional information about control arms.