Many people are completely unaware of the importance of spinal alignment. As a result, alignment problems affect what would normally be thought of as unrelated problems. But there is so much more to the story.
Dr. Sperry demonstrated that 90 percent of the energy output of the brain is used in relating the physical body to gravity. Only 10 percent has to do with thinking, metabolism, and healing, so when you have forward head posture, your brain will rob energy from your thinking, metabolism, and immune function to deal with abnormal gravity/posture relationships and processing.
So what is normal spinal alignment? When you look at the front of a person there shoulders and hips should be level. There should be a lordotic (to the front) curve in the neck and low back. If these are present forward head posture will be present and problems will develop.