Table 1 Baseline data

Fixed variables

 Age (years)^a

32.81 (8.59)

32.52 (8.91)

0.914

 BMI (kg/cm²)^a

24.52 (4.01)

24.96 (4.23)

0.645

 Years of illness

15.33 (6.81)

15.38 (9.26)

0.747

 Self-report of neck pain^b

18 (85.71%)

10 (47.62%)

0.046*

 Intensity of neck pain (NRS) ^a

4.23 (2.64)

1.95 (2.33)

0.005*

 Prophylactic medication^b

8 (38.10%)

2 (9.52%)

0.144

 Acute medication^b

10 (47.62%)

12 (57.14%)

0.879

Primary outcomes

 Frequency of headache (days with headache/month)^a

9.81 (8.80)

9.57 (6.88)

0.916

 Intensity of headache (NRS)^a

8.67 (1.11)

8.76 (1.51)

0.866

Secondary outcomes

 Cervical ROM^a

Movement

Flexion

62.48 (7.99)

60.24 (9.83)

0.394

Extension

73.86 (13.36)

72.57 (11.04)

0.727

Lateral flexion right

46.05 (5.51)

48.05 (8.26)

0.403

Lateral flexion left

51.86 (8.24)

48.52 (8.90)

0.214

Rotation right

68.19 (7.78)

66.24 (5.36)

0.373

Rotation left

69.29 (9.26)

67.62 (6.94)

0.507

 Pressure pain threshold^a

Muscle

Frontal

2.05 (0.72)

2.45 (1.02)

0.094

Anterior temporalis

1.76 (0.62)

2.02 (0.83)

0.267

Medium temporalis

2.20 (0.84)

2.39 (0.97)

0.498

Posterior temporalis

2.30 (0.91)

2.58 (1.07)

0.359

Sternocleidomastoid

1.85 (0.68)

2.21 (0.80)

0.122

Scapular levator

2.45 (1.02)

2.78 (1.17)

0.315

Upper trapezius

2.05 (0.72)

2.32 (0.91)

0.328

Suboccipital

1.81 (0.64)

2.15 (0.76)

0.106

 CCFT (mmHg)^a

Pressure level

25.14 (1.96)

24.95 (2.58)

0.794

 MIVC^a

Muscle group

Flexor

 Force_n (N/kg)

0.78 (0.29)

0.87 (0.20)

0.227

 Peak time (s)

2.30 (0.54)

2.31 (0.55)

0.927

Extensor

 Force_n (N/kg)

1.12 (0.50)

1.23 (0.49)

0.456

 Peak time (s)

2.50 (0.46)

2.65 (0.38)

0.257

 Endurance^a

Muscle group

Flexor endurance time (s)

44.24 (40.28)

39.90 (25.99)

0.651

Extensor endurance time (s)

174.43 (128.25)

229.19 (170.87)

0.238

 Questionnaires^a

Total score

MIDAS

58.38 (46.25)

45.05 (27.00)

0.199

NDI

13.00 (7.42)

9.38 (4.29)

0.072

ASC-12

9.76 (4.11)

7.76 (3.63)

0.118

TAMPA

37.48 (11.25)

35.1 (6.66)

0.377

PSFS

4.32 (2.52)

4.94 (2.55)

0.190