This term refers to how one may use their head.
In Airborne School, soldiers are taught to avoid using their 5th point of contact during a Parachute Landing Fall (PLF).
The instructors may also recommend to pull your 5th point of contact out of your 3rd point of contact (to pull your head out of your ass).
In my line of work, I've never had to pull anyone's head out of their ass (although this would be impressive), but I commonly refer to the 5th point of contact relative to the performance of the "upper quarter".
Thanks to our handheld devices and seemingly endless use of computers, more and more people are experiencing neck pain and / or other disruptions in the body that can be directly associated with a neck that is out of whack.
For any of you who've had whiplash or other such trauma, you know all too well what it means to cope with the lingering effects of neck issues.
The head is our 5th point of contact and it is crucial to give the positioning and function of our upper quarter serious consideration in preparation of sport and life.
Tip: a couple side flexions before you exercise is not going to help very much when it comes to controlling and stabilizing a 15-pound weight atop of your body (aka your cranium).
Do you think your neck is slowing you down?
I am your guy.