Forward head posture (FHP) is common and despite claims that FHP is related to neck pain, this relation remains controversial.
This systematic review looked at 15 cross-sectional studies and found that…
#1: Increased FHP was more prevalent in adults with neck pain versus those without
#2: Increased FHP was not associated with neck pain in adolescents
#3: Increased FHP was related to greater age and since greater age is associated with more likelihood of experiencing neck pain, FHP is then technically associated with neck pain.
“Age played an important role as a confounding factor in the relation between FHP and neck pain.” (Mahmoud et al 2019)
In summary: I wish there was evidence that correcting neck postures prevented or cured neck pain, but there isn’t. So can we stop our obsession with correcting people’s postures and making them feel guilty that their “poor posture” is the cause of their neck pain? Because it is most likely NOT true!
The belief and fear that their neck is so fragile and that slight postural changes is damaging it, is likely a far greater contributor to persistent neck pain. 
It’s time to move forward as a profession and appreciate that there are far more relevant risk factors for the development of neck pain. Let’s not exaggerate the importance of where exactly the head is positioned.