Table 4 Description of the studies measuring quality of neck motion

Alsultan 20.19, cross sectional

CNP and WAD, > 3 month, NPRS 4.08 (1.89), 8♂10♀, 32.22 (13.41), NR, NR, NR

8♂ 10♀, 25.89 (7.34), NR, NR, NR

NR, NR, NR

Yes, repeated movement within mid-range and three speeds, yes, yes, sitting with back support, no, within mid-range, slow, natural and fast, no

Optoelectronic system (BTS Bioengineering, Milan, Italy), 250, NR, NR, NR, NR

CNP. Helical axis (mean distance): F/E slow: 1.39 cm (0.25 cm), F/E natural: 1.46 cm (0.33 cm), F//E fast: 1.65 cm (0.39 cm), LF slow: 0.90 cm (0.23 cm), LF natural: 0.91 cm (0.23 cm), LF fast: 0.91 cm (0.25 cm), R slow: 0.90 cm (0.29 cm), R natural: 0.83 cm (0.15 cm), R fast: 0.84 cm (0.15 cm). Helical axis (mean angle): F/E slow: 4.22° (0.57°), F/E natural: 4.51° (0.73°), F//E fast: 3.88° (0.75°), LF slow: 8.61° (1.92°), LF natural: 8.96° (1.62°), LF fast: 9.04° (2.07°), R slow: 4.89° (0.71°), R natural: 4.98° (0.85°), R fast: 3.98° (0.42°).

HC. Helical axis (mean distance): F/E slow: 1.63 cm (0.31 cm)^a, F/E natural: 1.61 cm (0.28 cm)^a, F//E fast: 1.71 cm (0.31 cm)^a, LF slow: 0.93 cm (0.34 cm), LF natural: 1.02 cm (0.44 cm), LF fast: 0.97 cm (0.31 cm), R slow: 0.93 cm (0.22 cm)^a, R natural: 1.07 cm (0.33 cm)a, R fast: 0.99 cm (0.35 cm)a. Helical axis (mean angle): F/E slow: 4.39° (0.99°), F/E natural: 4.29° (0.91°), F//E fast: 3.89° (0.92°), LF slow: 9.21° (2.42°), LF natural: 9.70° (2.16°), LF fast: 9.20° (2.11°), R slow: 5.44° (1.64°)^a, R natural: 5.21° (1.04°)a, R fast: 4.99° (1.02°)^a

Bahat 2010, case control

CNP, 43.4 (5.3) months, VAS 3.3 (2.05), 9♂16♀, 39.0 (12.7), NR, local physiotherapy clinic, NR

11♂, 31♀, 35.3 (12.4), NR (NR), University of Haifa, NR

physiotherapist, experienced, NA

Yes, fast movement test, yes, yes, sitting, yes, to a target, fast as possible, no

Fastrak: Polhemus, 40 Hercules, 60 Hz, NR, NR, NR, NR

CNP. Mean velocity (°/sec). F: 24.4 (9.1). E: 29.1 (12.4). LR: 36.9 (15.2). RR: 39.8 (16.2). Peak velocity (°/sec²). F: 69.8 (34.7). E: 81.4 (39.7). LR: 108.5 (48.3). RR: 100.2 (43.6). Number of velocity peaks: F: 6.1 (2.6). E: 5.9 (2.1). LR: 6.1 (3.3). RR: 4.9 (2.8)

HC. Mean velocity (°/sec) F: 33.3 (12.6). E: 46.5 (16.3). LR: 56.4 (13.6). RR: 55.0 (15.9). Peak velocity (°/sec²) F: 105.0 (43.0). E: 138.6 (52.7). LR: 165.9 (51.9). RR: 162.2 (56.6). Number of velocity peaks: F: 5.0 (1.7). E: 4.8 (1.8). LR: 4.2 (1.8). RR: 3.6 (1.4)

Bahat 2015, case control

CNP, 93.03(104.46) months, VAS 36.42 (17.24) mm, 13♂, 20♀, 37.56 (9.95), NR (NR), University of Queensland and University of Haifa

15♂, 8♀, 33 (678), NR (NR), University of Queensland and University of Haifa, NR

Physiotherapists, experienced, NR

Yes, hit a target, yes, yes, sitting, fixed to back support, 40° of range, fast as possible, no

Head mounted display with a built-in motion tracker (Wrap™ 1200VR by Vuzix, New York, www.vuzix.com), 30, NR, NR, NR, NR

CNP. Mean velocity (°/sec): F: 20.14 (9.0), E: 29.08 (17.1), LR: 34.91 (14.0), RR: 32.88 (15.2). Peak velocity (°/sec): F: 50.34 (20.2), E: 55.30 (30.3), LR: 73.73 (28.7), RR: 66.64 (31.1). Number of velocity peaks: F: 1.24 (0.8), E: 1.40 (1.2), LR: 2.23 (1.0), RR: 1.99 (1.2)

HC. Mean velocity (°/sec): F: 83.82^a (33.3), E: 76.89^a (33.1), LR: 100.60^a (3.5), RR: 100.69^a (40.1). Peak velocity (°/sec²): F: 166.82^a (69.6), E: 149.05^a (68.6), LR: 261.59^a (104.4), RR: 220.93^a (89.2). Number of velocity peaks: F: 2.79^a (1.1), E: 2.42^a (1.3), LR: 3.5^a (1.2), RR: 3.5^a (1.3)

Baydal 2011, case control

WAD II and III, > 6 month, < 12 months, NR (NR), 15♂, 15♀, (NR), NR (NR) rehabilitation unit, NR. simulators, NR (NR), non-symptomatic WAD, (NR), 15♂, 14♀, NR (NR), NR (NR), IBV database, NR

15♂, 15♀, NR (NR), NR (NR), NR, NR

NR, NR, NR

Yes, repetitive flexion–extension, yes, no, sitting, back support, fixed to the back support, NR, self-selected, no

Video-photogrammetry system, NR, NR, NR, NR, NR

WAD II and III. Peak velocity (°/sec). F/E: 71 (22) WAD II and III. Peak acceleration (°/sec³). F/E: 168 (93)

WAD simulators. Peak velocity (°/sec). F/E: 29 (16) WAD simulators. Peak acceleration (°/sec³). F/E: 59 (36)

HC. Peak velocity (°/sec). F/E: 149 (50)^ab, HC. Peak acceleration (°/sec³). F/E: 410 (200)^ab

Cheng 2009, case control

CNP, 4.4 (2.2 ) years, NPRS 3.7 (0.8), 6♂, 6♀, 25.4 (2.1), NR (NR), NR, graduated students, teachers, or clinicians

7♂, 5♀, 24.9 (1.8), NR (NR), NR, graduated students

NR, NR, NR

NR, neck flexion/extension, yes, NR, sitting, back support, yes, not end range, self-selected, no

Electrogoniometer (CXTLA02, Crossbow, Inc., San Jose, CA, USA), NR, 0.1°, NR, NR, NR

CNP. Mean velocity (°/sec). F: 9.0 (2.1). E: 9.2 (1.3)

HC. Mean velocity (°/sec). F: 9.8 (3.8). E: 10.7 (2.7)

Feipel 2006, case control

WAD, 31 (32) months, NR (NR), 11♂, 18♀, 37 (14), NR (NR), NR, NR

12♂, 14♀, 35 (11), NR (NR), NR, NR

NR, NR, NR

Yes, AROM (F/E and R ) HRE, yes, yes, sitting back support, no, end range , self-selected, yes and no

3D electrogoniometer (CA 6000 Spine Motion Analyzer, O.S.I., Union City, CA),100 Hz, NR, NR, NR, NR

WAD. Peak velocity (°/sec). F: 121 (48. E: 118 (44). F-conjuct R: 2 (4), F-conjuct LF: 2 (5), E-conjuct R: 5 (6), E-conjuct LF: 1 (4)

HC. Peak velocity (°/sec). F: 157 (85). E: 147 (77). F-conjuct R: 2 (5), F-conjuct LF: 1 (5), E-conjuct R: 3 (6), E-conjuct LF: 4 (4)^a

Grip 2008, case control

CNP, > 3 months, VAS 49.2 (NR) mm, 7♂, 14♀, 49 (16), NR (NR), rehabilitation clinics and medical centres, NR. WAD I and II, > 3 months, VAS 66.1 (18.8) mm, 5♂, 17♀, 49 (15), NR (NR), rehabilitation clinics and medical centres, NR

8♂, 16♀, 50 (18), NR (NR), advertisement, NR

NR, NR, NR

Yes, fast head rotation, yes, yes, sitting, NR, NR, pain limit, fast as possible, no

ProReflex system (Qualisys Medical AB®, Gothenburg, Sweden), 120, 0.8 (1.73), NR, NR, NR

CNP. Mean velocity (°/sec). F: 44.6 (29.8). E: 60.2 (39.0). Pooled rotation: 60.2 (39.0)

WAD. Mean velocity (°/sec). F: 28.4 (22.7)^c. E: 21.1 (15.9)^c. Pooled rotation: 43.3 (30.4)^c

HC. Mean velocity (°/sec). F: 72.3 (21.7)^ab. E: 59.3 (20.7)^ab. Pooled rotation: 95.4 (29.9)^ab

Guo 2012, case control

NP, NR (NR), 27 (20) mm, 13♂, 14♀, 24.2 (5.9), NR (NR), NR, NR

Total 13, NR♂, NR♀, 20.9 (1.3), NR (NR), NR, NR

NR, NR, NR

NR, AROM, NR, NR, sitting, NR, NR, end range, self-selected, NR

Fastrak, Polhemius, USA, 120, NR, NR, AROM: > 0,791 Conjuct motion: > 0.4, NR

NP. F-conjuct RLF: 5.8 (3.3), F-conjuct RR: 6.3 (3.4), E-conjuct LLF: 8.3 (4.7), E-conjuct LR: 6.6 (2.8), LR-conjuct E: 9.9 (7.4), LR-conjuct LLF: 11.7 (7.9), RR-conjuct E: 8.8 (8.7), RR-conjuct RLF: 8.6 (9.1), LLF-conjuct F: 11.3 (7.1), LLF-conjuct F: 11.3 (7.1), LLF-conjuct LR: 16.7 (8.2), RLF-conjuct F: 13.9 (6.4), RLF-conjuct RR: 18.5 (7.2)

HC. F-conjuct RLF: 5.0 (2.5), F-conjuct RR: 4.5 (1.6)^a, E-conjuct LLF: 7.9 (4.7), E-conjuct LR: 7.3 (2.9), LR-conjuct E: 8.4 (3.8), LR-conjuct LLF: 12.0 (3.8), RR-conjuct E: 9.6 (2.9), RR-conjuct RLF: 10.7 (5.0), LLF-conjuct F: 10.2 (5.2), LLF-conjuct F: 10.2 (5.2), LLF-conjuct LR: 16.6 (7.3), RLF-conjuct F: 10.2 (5.6), RLF-conjuct RR: 16.6 (6.0)

Lemmers 2018, case control

Non-specific, NR, NPRS 4 (2), 16♂19♀, 48 (15), NR, physiotherapy clinic, NR

50♂ 50♀, 44 (16), NR, physiotherapy clinic, NR

NR, NR, NR

Yes, AROM, yes, yes, Sitting with back support, no, pain limit, self-selected, no

Flock of Birds electromagnetic tracking system (Ascension Technologies, Shelburne, USA©), no, NR, NR, NR, NR

Non-specific NP. Variability. F/E: 0.73 (0.32). LF: 0.45 (0.27). Non-specific NP. Root mean square of jerk. F/E: 12.97 (5.01). LF: 8.70 (3.62). Conjuct motion: F/E conjuct R: 18.84 (11.22), F/E conjuct LF: 15.12 (8.02), LF conjuct F/E: 59.25 (37.94), LF conjuct R: 59.01 (31.08)

HC. Variability. F/E: 0.98 (0.59). LF: 0.48 (0.31). HC. Root mean square of jerk. F/E: 13.26 (5.48). LF: 8,18 (3.67). Conjuct motion: F/E conjuct R: 18.84 (11.22), F/E conjuct LF: 15.12 (8.02), LF conjuct F/E: 59.25 (37.94), LF conjuct R: 59.01 (31.08)

Meisingset 2015, case control

NP, > 2 weeks, NPRS 4.6 (1.4), 20♂, 55♀, 43.1 (12.9), 24.9 (4.7), private physiotherapy clinic and specialised neck and back pain clinic at university hospital, NR

43♂, 48♀, 40.8 (13.8), 25 (3.5), university hospital, NR

Physiotherapist, well trained, NR

Unclear, AROM, JPE, unclear, yes, sitting, back support, fixed to back support, end range, self-selected, yes (JPE test)

Electromagnetic motion tracker system (Polhemus, Inc, Colchester, Vermont, USA), 240 Hz, NR, NR, NR, NR

NP. Peak velocity (°/sec) (adjusted for age and gender): F/E: 70.6 (35.8), R: 109.3 (45), LF: 57.9 (24.8). Conjuct motion (°) (adjusted for age and gender). F/E cunjuct: 12.3 (4.4), R cunjuct: 19.8 (8), LF cunjuct: 45.7 (24.7)

NP. Peak velocity (°/sec) (adjusted for age and gender): F/E: 115.6^a (35), R: 158.9^a (45.8), LF: 85.7^a (24.3). Conjuct motion (°) (adjusted for age and gender). F/E cunjuct: 16.5^a (4.4), R cunjuct: 25.1^a (7.8), LF cunjuct: 62.5 (24.3)

Röijezon 2010, case control

Non-specific neck pain (sample 1), 132 (NR) months, VAS 62 (16) mm, 0♂, 16♀, 48 (7), 26.6 (4.9), local papers, NR. Non-specific neck pain (sample 2), 120 (NR) months, NRS 5.4 (1.6), 0♂, 102♀, 51 (9), 26.7 (4.7), local papers, NR

0♂, 16♀, 45 (10), 23.8 (1.7), local papers, NR 0♂, 33♀, 47 (10), 24.9 (4.1), local papers, NR

NR, NR, NR

Yes and no, fast ROM, yes, yes, sitting, NR, NR, fast as possible, no

Electromagnetic tracking system (FASTRAK™,Polhemus Inc, USA), 60 Hz, NR, NR, peak speed: hc 0.75 (0.41–0.91), np 0.84 (0.58–0.94). ROM: hc 0.64 (0.21–86), np 0.86 (0.63–0.95), peak speed: hc 33 (25–52), np 41 (31–64). hc ROM: 4.2 (3.1–6.4), np 3.8 (2.8–5.9)

NP. Peak velocity (°/sec). R: 226 (88). SID (%): 18.1 (6.5), CM 12.4 (3.7)

HC. Peak velocity (°/sec). R: 348 (92) SID (%):13.7 (4.7)

CM 18.8 (7.5)

Sjølander 2008, case control

Insidious neck pain, 97 (68) months, VAS 52 (16) mm, 0♂, 9♀, 40 (9), NR (NR), rehabilitation centre, NR. WAD II and III, 76 (84) months, VAS 45 (19) mm, 2♂, 5♀, 45 (11), NR (NR), rehabilitation centre, NR

3♂, 13♀, 41 (9), NR (NR), local community, NR

NR, NR, NR

Yes, AROM in rotation, yes, yes, standing, NA, yes, fast as possible, NR

Electromagnetic tracking system, 60, NR, NR, NR, NR

Insidious neck pain. Peak velocity (°/sec): **out-left: 95.3 (27.5), out-right: C12, in-left:89.7 (26.3), in-right: 85.4 (32.4), total jerk index: out-left: 15.9 (9.5), out-right: 14.1 (9.7), in-left: 16.2 (8.7), in-right:17.3 (11.3)

WAD. Peak velocity (°/sec): out-left: 108.6 (20.4), out-right: C12, in-left: 103.7 (19.1), in-right: 96.4 (27.4), total jerk index: out-left: 13.1 (5.1), out-right: 13.6 (9.1), in-left: 11.1 (6.1), in-right: 15.2 (10.6)

HC. Peak velocity (°/sec): out-left: 132.8 (39.6), out-right: C12, in-left: 119.5 (28.6), in-right: 116.9 (28.6), total jerk index: out-left: 7.5 (4.4)^ab, out-right: 7.7 (4.2), in-left: 8.6 (4.9)^ab, in-right: 9.4 (7.1)

Tsang 2013, case control

CNP, 5.13 (NR) years, NPRS 38.97/100, 9♂25♀, 38.44 (10.87), 21.77 (3.03), local community, NR

9♂ 25♀, 34.35 (9.08), 22.07, local community, NR

NR, NR, NR

Yes, AROM, yes, yes, sitting, NR, no, end range, NR, no

Fastrak, Polhemus Inc., Colchester, VT, USA, 30, NR, NR, NR, NR

CNP. Mean velocity (°/sec). F: ≈ 62 (21). E: ≈ 57 (16). LR: ≈ 134 (52). RR: ≈ 129 (52). LLF: ≈ 52 (16). RLF: ≈ 52 (10)

HC. Mean velocity (°/sec). F: ≈ 83 (26). E: ≈ 78 (26). LR: ≈ 186 (52). RR: ≈ 181 (52). LLF: ≈ 72 (31). RLF: ≈ 72 (31).

Vogt 2007, case control

CNP, NR (NR), VAS 37 (8) mm, 6♂, 10♀, 55.8 (2.8), NR (NR), co-operating rehabilitation clinics, NR

8♂, 10♀, 56.6 (3.5) (3.5), NR (NR), advertisements, NR

NR, NR, NR

Yes, AROM, yes, yes, sitting, NR, end range, self-selected, NR

Zebris CMS 70©, Germany, 30, > 0.6 mm, NR, > 0.92 (r = 0.996–0.921; p < 0.001), NR

CNP. CV (%). F: 12.1 (12.0). E: 11.2 (9.5). LR: 8.0 (7.1). RR: 8.0 (7.1). LLF: 12.0 (3.3). RLF: 13.3 (4.0).

HC. CV (%). F: 2.8 (1.3). E: 1.9 (0.9). LR: 1.7 (1.0). RR: 1.7 (1.0). LLF: 5.3 (3.0). RLF: 5.1 (2.6).

Woodhouse 2008, case control

WAD I and II, > 6 months (NR), NPRS 5.60 (2.49), 22♂, 34♀, 38.19 (10.8), NR (NR), referred, NR. CNP, > 6 months (NR), NPRS 3.84 (− 1.74), 19♂, 38♀, 43.7 (12.6), NR (0), physiotherapists and general practitioners, NR

29♂, 28♀, 38.2 (10.9), NR (NR), different, NR

NR, NR, no

NR, AROM, NR, yes, sitting, NR, end range, NR, eyes closed

3-Space Fastrak , 120 Hz, reference, NR, NR, NR

WAD. F/E-conjuct R: 3.95 (1.89), F/E-conjuct LF: 3.66 (1.82), R conjuct-F/E: 6.89 (3.22), R conjuct-LF: 7.00 (3.52), R conjuct-LF: 7.00 (3.52), LF-conjuct F/E: 6.59 (2.98)

CNP. F/E-conjuct R: 4.58 (1.32)^c, F/E-conjuct LF: 4.18 (1.24), R-conjuct F/E: 8.99 (3.26)^c, R-conjuct LF: 8.87 (4.09)^c, R-conjuct LF: 8.87 (4.09)^c, LF-conjuct F/E: 7.57 (3.12)

HC. F/E-conjuct R: 5.10 (1.53)^a, F/E-conjuct LF: 5.24 (2.26)^ab, R-conjuct F/E: 12.79 (5.23)^ab, R-conjuct LF: 13.15 (4.08)^ab, R-conjuct LF: 13.15 (4.08)^ab, LF-conjuct F/E: 8.43 (2.69)^ab