Treating forward head posture (FHP) is not rocket science, it's just hard work. I find people tend to be either floppy or rigid in their postural fault. In your floppy patients they have good ROM but have dreadful postural sense so general postural awareness is required and effort++ required to maintain a posture they can attain immediately. I find Clinical Pilates and use of a lumbar roll great for these patients.

In your other patient type, rigidity in the upper thoracic and cervico-thoracic junction (CTJ) is to blame, usually due to obstruction by a posterior disc derangement or adaptive shortening over many years of never having good posture. In this situation you will often note a dowagers hump deformity of ther CTJ. Treatment requires lots and lots and lots of retraction exercises (opposite of FHP). A combination of active/patient generated retraction with clinician overpressure at the CTJ/Upper Tx in sitting followed by or alternating with retraction/extension in lying +/- with manual traction (see McKenzie Cx/tx text for details) works well. This is just in the clinic though, this will be useless if they don't do their own retraction exercises as often and every hour or two for as long as it takes.

I will almost always tape my patients into adequate thoracic extension for at least 24 hours in both rigid and floppy patients. Patients just don't realise most of the time that they have forward head posture and they give in to thoracic flexion. They need a constant reminder (a good kick up the behind basically) to sort themselves out.

Correction of FHP is more about what the patient does to themselves than what you do to them....

Angel