Editing HANS device (section)

==Description==
[[File:Hans - head and neck safety system.svg|thumb|left|'''1.''' HANS device, '''2.''' Tether (one per side), '''3.''' Helmet anchor (one per side), and '''4.''' Shoulder support.]]
Primarily made of [[carbon fiber reinforced polymer]], the HANS device is shaped like a "U", with the back of the "U" set behind the nape of the neck and the two arms lying flat along the top of the chest over the [[pectoral muscles]]. The device, in general, is supported by the shoulders. It is attached only to the helmet, not to the belts, the driver's body, or the seat; the helmet is attached to the device with the help of an anchor on each side, much like the [[Hutchens device]], but placed slightly back. In a properly installed 5- or 6-point [[seat belt#Five-point harnesses|racing harness]], the belts that cross the driver's upper body pass directly over the HANS device on the driver's shoulders and buckle at the center of the driver's abdomen. Therefore, the HANS device is secured by the body of the driver, not the seat.

The purpose of the HANS device is to keep the head from whipping in a crash, preventing excessive rotational movement as a secondary protection, without otherwise restricting movement of the neck. In other words, it allows the wearer's head to move normally, but prevents or restricts head movements during a crash that would exceed the normal articulation range of the [[Human musculoskeletal system|musculoskeletal system]] and cause severe injury. In any kind of crash, the person's body, when not protected, is decelerated by the seat belt, with the head maintaining velocity until it is decelerated by the neck. The HANS device maintains the relative position of the head to the body, in addition to transferring energy to the much stronger chest, torso, shoulder, seat belts, and seat as the head is decelerated.