Table 4.

Search strategy and number of founded papers in each database

Database	No. of papers	Keywords
PubMed	786	((((((((((((((cervical posture) OR cervical postures) OR forward head posture) OR forward head postures) OR forward posture) OR forward postures) OR head posture) OR head postures) OR neck posture) OR neck postures) OR neck posturing) OR forward head tilt) AND (“2009/01/01”[PDat]: “2018/09/19”[PDat]) AND English[lang])) AND ((((((((((((((neck pain) OR cervical pain) OR neck ach) OR neck disability) OR Bournemouth Neck Questionnaire) OR Cervical Spine Outcomes Questionnaire) OR Copenhagen Neck Functional Disability Scale) OR (Neck Pain and Disability Scale)) OR Northwick Park Neck Pain Questionnaire) OR Neck disability index) OR acute neck pain) OR chronic neck pain) OR “Neck Pain”[Mesh]) AND (“2009/01/01”[PDat]: “2018/09/19”[PDat]) AND English[lang])
Cochrane	241	Neck pain or cervical pain or neck ach or neck disability or “Bournemouth Neck Questionnaire” or “Cervical Spine Outcomes Questionnaire” or “Copenhagen Neck Functional Disability Scale” or “Neck Pain and Disability Scale” or “Northwick Park Neck Pain Questionnaire” or “Neck disability index” or MeSH descriptor: [Neck Pain] explode all trees AND cervical posture or forward head posture or forward posture or head posture or neck posture or forward head tilt AND Publication Year from 2009 to 2018, in Trials and Methods Studies (Word variations have been searched)
PEDro	5	Key words (head posture*AND neck pain) advanced search, Publication Year from 2009, clinical trials, Subdiscipline: musculoskeletal, topic: chronic pain, body parts: head or neck
EMBASE	164	(‘neck’:ab,ti AND ‘pain’:ab,ti OR ‘cervical pain’:ab,ti OR ‘neck ach’:ab,ti OR ‘neck disability’:ab,ti OR ‘bournemouth neck questionnaire’:ab,ti OR ‘cervical spine outcomes questionnaire’:ab,ti OR ‘copenhagen neck functional disability scale’:ab,ti OR (‘neck pain’:ab,ti AND ‘disability scale’:ab,ti) OR ‘northwick park neck pain questionnaire’:ab,ti OR ‘neck disability index’:ab,ti) AND (‘head and posture’:ab,ti OR ‘cervical posture’:ab,ti OR ‘forward head posture’:ab,ti OR ‘forward posture’:ab,ti OR ‘neck posture’:ab,ti OR ‘forward head tilt’:ab,ti OR ‘head position’:ab,ti) AND [English]/lim AND [2009-2018]/py
CINAHL	95	((((((((((((((((neck pain) OR cervical pain) OR neck ach) OR neck disability) OR Bournemouth Neck Questionnaire) OR Cervical Spine Outcomes Questionnaire) OR Copenhagen Neck Functional Disability Scale) OR (Neck Pain and Disability Scale)) OR Northwick Park Neck Pain Questionnaire) OR Neck disability index) OR acute neck pain) OR chronic neck pain)) AND (((((((((((((cervical posture) OR cervical postures) OR forward head posture) OR forward head postures) OR forward posture) OR forward postures) OR head posture) OR head postures) OR neck posture) OR neck postures) OR neck posturing) OR forward head tilt)); published date: 2009 January 1 to 2018 December 31, language: English