The trailer hitch has a pair of tubular housings 22 and 23, a coil compression spring 29 in each housing, and a cable 30 or 31. Methods for using the combinations to treat medical conditions, such as cancer, are also provided. Each of the plurality of keycaps has a touch surface for receiving a press force. Consequently, the vehicle may be more effectively steered as a result not interfering with its tracking or bringing about creep thereof.