sometimes if I sit in the same position where my head and neck doesn't have much support for example sitting in a dining room chair for hours at a computer, anyway because I have no head rest the neck and muscles in the back of the neck that attach to my head will start hurting with a feeling simular to a headache at the base of my head (the spot where if you follow your neck up to the head under the hair and there is a boney bump.) anyway not staying on line so long a streatch and using chairs with head and neck supports help and I no longer have back of the head headaches.