Table 5

Secondary outcome measures results
StudyIntervention (N)Comparator (N)Secondary outcome measuresKey findings
Bodes-Pardo et al. []Trigger point therapy + stretching (10)Sham trigger point therapy (10)Neck pain intensity (VAS), Cervical spine ROM (CROM device), Cervical pressure pain threshold (algometer), Deep Cervical flexors performance (CCFT)P < 0.001 for neck pain intensity, CCFT, pressure pain thresholds and CROM at 1 week. MCID reached for CROM (MD = 8.2–13.6°)
Chaibi et al. []Cervical manipulation (4)Sham manual therapy (4); Control (4)CGH duration (hrs/day)P values not calculated due to small sample size
Dunning et al. []Cervical and thoracic manipulation (58)Cervical and thoracic mobilization and cranio-cervical flexion exercises (52)CGH duration (hrs in the last week), Disability (NDI), Global Rating of Change scale (GRC), Drugs intakeP < 0.001 for NDI and GRC at 1, 4 weeks and 3 months. P < 0.05 for headache duration at 1 week and 3 months. P < 0.001 for medication intake at 3 months. MCID proposed by the study for NDI were reached (MD = − 11,6 at 4 weeks)
Esin et al. []Kinesiotaping (34)Sham taping (34); Education and autonomous rehabilitation instructions (33)Pressure pain threshold (cervical, sub-occipital, trapezius muscles)P < 0.01 for pressure pain threshold at 4 and 8 weeks
Haas et al. []Cervical and thoracic manipulation—8 sessions (20)Moist heat and light massage—8 sessions (20)Disability (MVK), Drugs intake (N in the past 4 weeks), Other headache frequency (episodes in the past month)Intervention main effect: P < 0.05 for other headache frequency and medication intake at 24 weeks. P < 0.05 for Disability at 12 weeks
Cervical and thoracic manipulation—16 sessions (20)Moist heat and light massage—16 sessions (20)Disability (MVK), Drugs intake (N in the past 4 weeks), Other headache frequency (episodes in the past month)Intervention main effect: P < 0.05 for other headache frequency and medication intake at 24 weeks. P < 0.05 for Disability at 12 weeks
Haas et al. []Cervical and thoracic manipulation—6 sessions (65)Sham massage (64)Disability (HIT-6), Perceived change (0-points scale), Quality of life (VAS 0–100), Subjective CGH improvement (20-points scale), satisfaction (7-points Likert scale), neck pain frequencyP < 0.05 for Disability at 6 and 24 weeks
Cervical and thoracic manipulation—12 sessions (64)Sham massage (64)Disability (HIT-6), Perceived change (0-points scale), Quality of life (VAS 0–100), Subjective CGH improvement (20-points scale), satisfaction (7-points Likert scale), neck pain frequencyP < 0.05 for Disability, neck pain frequency and intensity at 6 weeks. P < 0.05 for perceived change at 6 and 24 weeks
Cervical and thoracic manipulation—18 sessions (63)Sham massage (64)Disability (HIT-6), Perceived change (0-points scale), Quality of life (VAS 0–100), Subjective CGH improvement (20-points scale), satisfaction (7-points Likert scale), neck pain frequencyP < 0.05 for Disability, perceived change and neck pain frequency at 6 and 24 weeks. P < 0.05 for neck pain intensity at 6 weeks
Hall et al. []C1-2 SNAG (16)Sham SNAG (16)Cervical spine ROM (CROM device during FRT)P < 0.001 for CROM (FRT), MCID reached (MD = 11–20°) after 1st intervention
Jafari et al. []Trigger point therapy (9)No treatment control (10)Change in elastic modulus in trigger point area (Pa), Trigger point area (cm2), Pressure pain threshold (Algometer, VAS), CGH duration (hrs in the last 2 weeks)P < 0.05 for headache duration, pressure pain threshold, TrP area at 3 weeks
Jull et al. []Spinal mobilization and manipulation (51)No treatment control (48)Cervical pressure pain threshold (VAS), Deep Cervical flexors performance (CCFT), Pain with neck movement (VAS), Neck pain index (Northwick Park), CGH duration (hrs in the past week), Medication intakeP < 0.05 for neck pain index, headache duration and pain on palpation at 7 weeks and 12 months. P < 0.05 for pain with neck movements at 7 weeks. P < 0.015 for medication intake at 12 months. P > 0.05 for CCFT at 7 weeks and 12 months
Low load endurance exercises for cervico-scapular muscle (52)No treatment control (48)Cervical pressure pain threshold (VAS), Deep Cervical flexors performance (CCFT), Pain with neck movement (VAS), Neck pain index (Northwick Park), CGH duration (hrs in the past week)P < 0.05 for neck pain index and pain with neck movement at 7 weeks and 12 months. P < 0.05 for pain on palpation at 7 weeks. P < 0.015 for medication intake at 12 months. P < 0.001 for CCFT at 7 weeks and 12 months
Combination of the above (49)No treatment control (48)Cervical pressure pain threshold (VAS), Deep Cervical flexors performance (CCFT), Pain with neck movement (VAS), Neck pain index (Northwick Park), CGH duration (hrs in the past week)P < 0.05 for neck pain index, headache duration and pain on palpation at 7 weeks and 12 months. P < 0.05 for pain with neck movements at 7 weeks. P < 0.015 for medication intake at 12 months. P < 0.001 for CCFT at 7 weeks, P < 0.01 at 12 months
Malo-Urriès et al. []Upper cervical mobilization (41)No treatment control (41)General cervical spine ROM (using CROM device), Upper cervical spine ROM (using CROM device during FRT), Cervical, suboccipital, trapezius pressure pain threshold (Algometer, Kg/cm2)P > 0.05 for pressure pain thresholds. P < 0.05 for general cervical ROM (flexion, left rotation), P = 0.006 for right FRT and P < 0.001 for left FRT post intervention. MCIDs for FRT were reached (MD + 5.4° to 7.4°)
Nilsson et al. []Cervical manipulation (28)G2: Deep friction massage, trigger point therapy to upper back and neck, laser light therapy (26)Medication intake (N/day)P = 0.14 at week 5, with P < 0.05 after X2 test for type-2 error. Within-group changes saw P < 0.0001 in the experimental group
Sedighi et al. []Sub-occipital and trapezius dry needling (15)Sham sub-occipital and trapezius dry needling (15)Cervical spine ROM (4-points scale), Sub-occipital and trapezius pressure pain threshold (4-points scale), Function (FRI)P < 0.01 for FRI at 1 week. Within-group changes only were provided for other outcomes, with P < 0.05 for ROM and P < 0.001 for trigger point tenderness in the MT group at 1 week
Sharma et al. []Multimodal therapy (spinal mobilization, low load and mobility exercise program for the cervical spine, postural correction intervention) (9)Postural correction (9)Deep Cervical flexors performance (CCFT), Disability (NDI), CGH duration (hrs in the past week)P = 0.001 for all outcome measures at 4 weeks. NDI MCID cannot be assessed due to absence of raw data
Exercise therapy (low load and mobility exercise program for the cervical spine, postural correction intervention) (9)Postural correction (9)Deep Cervical flexors performance (CCFT), Disability (NDI), CGH duration (hrs in the past week)P = 0.001 for all outcome measures at 4 weeks. NDI MCID cannot be assessed due to absence of raw data
von Piekartz et al. []Manual therapy + exercise (TMJ manual therapy, TMJ coordination and ROM exercises) (22)Usual care (cranio-cervical manual and exercise therapy) (21)Anamnestic questionnaire (AQ), Graded-chronic pain status (GCPS-NL, scale 1 to 4), Temporo-mandibular pressure pain threshold (Digital algometer, Kgf), Disability (NDI), TMJ noise (presence/absence of click), TMJ-related disability (GCPS), TMJ ROM (cm), Pain with TMJ opening, Mandibular deviation (presence/absence)Between-group P < 0.05 for all outcomes at 3 months. P < 0.05 for AQ, GCPS, pressure pain thresholds, TMJ noise, pain with TMJ opening at 6 months. MCID proposed by the study reached for NDI (− 6.5 at 3 months), not for mouth opening ROM at both timepoints
Yang and Shanb []Hot pack and low frequency therapy on trapezius + cranio cervical flexion exercises (10)Hot pack and low frequency therapy on trapezius (10)Muscular fatigue (Hz), Muscle tone (N/m)P < 0.05 for change in muscle fatigue for SCM and UFT muscles at 2 and 4 weeks. P < 0.05 for change in muscle tone at left UT and bilateral SCM at 2 and 4 weeks
Hot pack and low frequency therapy on trapezius + sub-occipital relaxation (10)Hot pack and low frequency therapy on trapezius (10)Muscular fatigue (Hz), Muscle tone (N/m)P < 0.05 for change in muscle fatigue for SCM and UFT muscles at 2 and 4 weeks. P < 0.05 for change in muscle tone at left UT and bilateral SCM at 2 and 4 weeks
Youssef and Shanb []Cervical mobilization and exercise (20)Massage and exercise (18)Cervical spine ROM (cm), Disability (NDI), CGH duration (hours/week)P < 0.05 for all ROM directions and CGH duration at 7 weeks. Between-group P = 0.26 for NDI at 7 weeks, but within-group P < 0.001 and MCID were reached (− 27.2 at 7 weeks)
Abdel et al. []Exercise Therapy (stretching, isometric contractions, postural correction) + Graston technique (30)Exercise Therapy (stretching, isometric contractions, postural correction) (30)Disability (NDI), Cervical spine ROM (CROM device), HD (hours in the past week), Medication intakeWithin-group P < 0.05 for flexion, left lateral flexion and right lateral flexion CROM at 2 weeks in the conrol group; P < 0.0001 for all other outcomes at all timepoints in both groups, and for between-groups differences at 4 weeks favouring Graston technique. MCIDs reached for NDI (MD = 11.1 at 4 weeks)
Dunning et al. []Spinal manipulation and electrical dry needling (74)Spinal mobilization and scapular and cranio-cervical exercise (68)HD (hours in the past week), Disability (NDI), Global Rating of Change (GROC), Medication intakeBetween-group P < 0.001 for HD at all timepoints, for GRC and Medication intake at 3 months. MCIDs reached for NDI (MD = 14.4 at 4 weeks and 16.9 at 3 months) and between-group P < 0.001 at all timepoints
Lerner-Lentz et al. []Spinal manipulation, cranio-cervical and scapular exercise (21)Spinal mobilization and scapular and cranio-cervical exercise (24)Disability (NDI), Headache Impact Test (HIT-6), Globale Rate of Change (GRC), Patient Acceptable Symptoms Scale (PASS)MCIDs reached for NDI in both groups (MD = 13.9 for manipulation and MD = 12.8 for mobilization group at 1 month). Within-group P < 0.05 at all timepoionts for all groups for all secondary outcomes. Between-groups P > 0.05 at all time points
Moustafa et al. []Myofascial release, spinal mobilization, cranio-cervical and scapular exercise, Dennerol cervical extension traction (30)Myofascial release, spinal mobilization, cranio-cervical and scapular exercise (30)Disability (HIT-6; HDI), Radiographic cervical alignment variables, Daily Defined Dose (DDD)Within-group P < 0.001 for HIT-6, HDI, DDD at 10 weeks for the control group, and at all time points for the intervention group. Between group P > 0.05 at 10 weeks for HIT-6, HDI, DDD. Between group P < 0.001 at all timepoints favouring the experimental group for Radiographic variables, and for all other outcome measures at 1 and 2-years follow ups

For each trial, the intervention and comparator(s), the number of participants for each group, the secondary outcome measures of interest, the RoB score, and mean changes with statistical and clinical significance values (P value and MCID) at each time-point are described.

N number of participants, CCFT cranio-cervical flexion test, FRT flexion-rotation test, TMJ temporo-mandibular joint, ROM range of motion, HD headache duration, NDI neck disability index, MCID minimal clinically important difference