Ford F-150 2010 Owner's Manual page 161

To adjust the head restraint, do the following:
1. Raise the head restraint by
pulling up on the head restraint.
2. Lower the head restraint by
pressing and holding the guide
sleeve adjust/release button and
pushing down on the head restraint.
Properly adjust the head restraint so that the top of the head restraint is
even with the top of your head and positioned as close as possible to the
back of your head. For occupants of extremely tall stature, adjust the
head restraint to its full up position.
WARNING: The adjustable head restraint is a safety device.
Whenever possible it should be installed and properly adjusted
when the seat is occupied.
Seating and Safety Restraints
161