The loss of the normal spinal alignment, particularly the loss of the normal spinal lordosis in the neck AND low back, is one of the most common causes for neck pain and poor posture. This causes a condition call Forward Head Posture.
When the head shifts forward, it increases the mechanical work load for the ENTIRE spine. Particularly hard hit areas are just under the skull, where the shoulders and neck meet, between the shoulder blades and the very low back.
Muscles that attach to the bones in the cervical spine become over stretched with the loss of the cervical curve and begin to fatigue. That is often when the person feels PAIN, or very TIGHT muscles.