Table 2, continued
Authors Sample size
NP status	Methodological quality of studies	Intervention $+$ Co intervention	Comparison group $+$ co intervention	Outcomes measures of interest	Clinical relevance status on timing outcomes: between groups $P$ value and effect sizes
Kanlayanaphotporn et al.
$n=$ 60
CNP	Level A
10/11
No for care provider blinded	IG: MT2 on Cx symptomatic levels (PAIVMS)
1 time	CG: random MT2 Cx (PAIVMS) 1 time	Pain (VAS) Functional disabilities (CROM)	NO
NO
Aquino et al.
$n=$ 48
CNP	Level A
9/11
No for patient and care provider not blind	IG: MT2 Cx symptomatic levels (PAIVMS)
1 time	CG: random MT2 (PAIVMS), away from the concordant segment
1 time	Pain (NRS)	NO
Schomacher
$n=$ 126
CNP	Level A
10/11
No for care provider blinded	IG: MT2 Cx symptomatic levels (PAIVMS)
1 time	CG: MT2 Cx (PAIVMS), 3 levels away from the concordant segment 1 time	Pain (NRS)	NO
Bronfort et al.
$n=$ 191
CNP	Level A
9/11
No for patient and care provider blinded	IG1: MT3 on Cx-Tx (HVLA $+$ STT) $+$ exercise IG2: MT3 on CX-Tx (HVLA $+$ STT) alone (sham microcurrent)
20 times (1h) over 11 weeks & home exercises for all groups	CG: MedX (Exercise with specific devices sessions)	Pain (NRS) Functional disabilities (NDI)
(CROM)
-Flex/Ext
-Rot
-Lat Flex
Overall Improvement
(SF-36)	NO
NO
YES:
IG1 vs IG2: at 11 weeks ($p<$ 0.05; MD $=$ 6.7)
CG vs IG2: at 11 weeks ($p<$ 0.05; MD $=$ 5.2) YES: IG1 vs IG2: at 11 weeks ($p<$ 0.05; MD $=$ 6.7)
YES: IG1 vs IG2: at 11 weeks ($p<$ 0.05; MD $=$ 5.6)
NO
Evans et al.
$n=$ 270
CNP	Level A
9/11
No for patient and care provider not blind	IG1: MT1 Cx-Tx $+$ Exercise IG2: High Exercise (High dose supervised strengthening exercise)	CG: HEA (Home Exercise and advice)	Pain (NPRS)
Disability (NDI)
Overall Improvement
(SF-36)	IG1 vs CG: YES at 12 weeks ($p<$ 0.001; SMD $=$ 0.9; MD $=$ 1.4)
IG2 vs CG: YES at 12 weeks ($p=$ 0.001, SMD $=$ 0.7; MD $=$ 1.2) IG1 vs CG:Yes at 12 weeks ($p=$ 0.001; SMD $=$ 0.5; MD $=$ 4.3) : YES: at 12 weeks ($p<$ 0.001; MD $=$ 1.3), at 52 weeks, $p=$ 0.001; MD $=$ 0.8)
IG2 vs CG: YES: at 12 weeks ($p<$ 0.001; MD $=$ 1.1), at 52 weeks ($p=$ 0.03, MD $=$ 0.5)
Akhter et al. $n=$ 62 CNP	Level B
7/11
No for allocation concealed, No for patient and care provider blinded, dropouts, ITT	IG: MT1 Cx $+$ exercise (6 sessions over 3 weeks for both groups)	CG: Supervised exercise alone	Pain (VAS) Functional disabilities (NDI)	NO
NO

CNP: chronic neck pain/VAS: Visual Analogue Scale/NDI: Neck Disability Index/CROM: Active Cervical Range Of Motion/PPT: Pressure Pain Threshold/US: ultrasound/NPRS: Numeric Pain Rating Scale/FABQ: Fear-Avoidance-Belief-Questionnaire/SF-36: Short-form-health-survey/NPQ: Northwick Pain Questionnaire/UMC: Usual Medical Care/Cx: cervical/Th: thoracic/MOB: Mobilisation/SNAGs: Sustained Natural Apophyseal Glides/HVLA: high velocity low amplitude thrust/IG: Intervention Group/CG: Control Group/IRT: Infrared Radiation Therapy/PAIVMS: Passive Accessory Intervertebral Movements/STT: Soft-Tissues-Techniques/SUS: Sham Ultrasound/Yes: significant difference between groups with moderate to large clinical effect size/No: no significant difference between groups with small clinical effect size on all timing outcome measures.