Table 1 Summary of subject and study descriptive characteristics, intervention and comparator arms

Brontford et al. 2012 [36]

United States

47.55

(mean)

191 (63.1)

NPRS Pain Score

2, 3, 8, 12, 26, 52 weeks

Manipulation/mobilization of hypomobile segments

NSAIDS, acetaminophen, opioid, muscle relaxant

Calvo-Lobo et al. 2018 [41]

Venezuela

32.05

(mean)

51 (21)

NPRS Pain Score

1, 15, 30 weeks

Non-invasive neural mobilization technique using a cervical contralateral glide mobilization

Ibuprofen

De Hertogh et al. 2009 [37]

Belgium

43.22

(mean)

37 (9)

VAS pain score

7, 12, 26 weeks

Manual therapy (articular mobilisations and low load exercises)

Usual Care/Medication (NSAIDS, triptans)

Giles et al.

1999 [38]

Australia

38.75 (median)

57 (23)

VAS pain score

4 weeks

Manual Therapy SMT (high velocity/low amplitude spinal manipulation)

Medication (NSAID)

Giles et al. 2003 [40]

Australia

39

(median)

75 (31)

VAS pain scale

Initial visit, 2, 5 and 9 weeks

Spinal manipulation

Celebrex (200-400 mg/day), Vioxx (12.5-25 mg/day), paracetamol (up to 4 g/day)

Hoving et al. 2002 [44]

Netherlands

45.25

(mean)

124 (53.9)

NPRS pain score

3, 7

Manual Therapy

(Muscular and articular mobilizations, coordination and stabilization techniques)

Continued Care (paracetamol or nonsteroidal anti- inflammatory drugs)

Hoving et al. 2006 [39]

Netherlands

45.25

(mean)

124 (53.9)

NPRS pain score

3, 7, 13, 26, 52

Manual Therapy

(Muscular and articular mobilizations, coordination and stabilization techniques)

Continued Care (paracetamol or nonsteroidal anti- inflammatory drugs)

Lee et al. 2021 [42]

Korea

38.4

(mean)

108 (35)

VAS & NPRS pain score

5, 12.9, 25.8, 38.7, 51.6 weeks

Chuna manual therapy (Manipulation/mobilization using distraction & adjustment methods)

Usual care (PT + oral medications - Analgesics (paracetamol or NSAID))

Muller et al. 2005 [57]

Australia

39

(median)

42 (21.99)

VAS pain score

9 & >103.2 weeks

Manipulation (left to discretion of provider)

Medication (Celecoxib, rofecoxib, acetaminophen)

Walker et al. 2008 [43]

United States

47.5

(mean)

94 (31)

VAS pain score

3, 6, 103.2 weeks

Manual therapy and Exercise (1/3 Thrust or Non-thrust, muscle energy, stretching)

Usual Care (general practitioner care + instructions to continue prescription medication– NSAIDs, Cervical ROM exercises)