Intrarater and Inter-rater Reliability of Maximal Voluntary Neck Muscle Strength Assessment Using a Handheld Dynamometer in Women With Headache and Healthy Women

Cervical muscle parameters and allodynia in migraine and cervical pain-A controlled study

BACKGROUND

Neck pain is common among individuals with migraine, but there is a lack of information of how this comorbidity can be associated with cervical muscle function. This controlled cross-sectional study aimed to compare cervical muscle function, activity, and sensitization in women with migraine, neck pain, both, and neither.

METHODS

This study included women, between 18 and 55 years old, with either episodic migraine with or without aura, without any concomitant headache diagnosis; chronic neck pain, with at least moderate intensity and mild disability; or neither headache nor neck pain. Pain pressure threshold, allodynia, muscle strength, and endurance and cervical muscles activity were evaluated.

RESULTS

One hundred subjects, with mean age of 30.4 years old, were stratified by diagnosis (n = 25 per group) and by self-reported pain during tests. Lower endurance during flexion was observed for migraine and neck pain (34s) relative to neck pain alone (45s), migraine (40s), and controls (58s) (p = 0.04). For extensor endurance, means were 142s, 166s, 215s, and 270s, respectively (p < 0.001). Endurance times were impacted by the presence of test-induced pain decreasing about 40%-53% of the performance. Diagnostic groups did not differ significantly in strength (p > 0.05), but all pain groups presented significantly higher proportion of test-induced pain, lower muscle activity during the maximal isometric voluntary contractions, and lower pressure pain thresholds.

CONCLUSION

Patients with migraine, chronic neck pain, and the association of both present altered cervical muscle function and activity. Also, test-induced pain impacts significantly on neck muscles endurance.

SIGNIFICANCE

The diagnosis of migraine and chronic neck pain is associated with altered function and activity of the cervical muscles. However, the test-induced pain had an important contribution to worse cervical muscle endurance. This suggests that the therapeutic approach should focus on de-sensitization of the trigeminal-cervical complex when dealing with the comorbidity of migraine and cervical pain.

Reference Values for Cervical Muscle Strength in Healthy Women Using a Hand-Held Dynamometer and the Association with Age and Anthropometric Variables

Knowledge of reference values for cervical muscle strength is a key tool for clinicians to use as a clinical reference measure and to establish goals during rehabilitation. The objective was to establish reference values for the maximal strength of cervical muscles in healthy women using a handheld dynamometer and verify the association of cervical muscle strength with age and anthropometric measurements. A hundred women were classified into four groups (n = 25) according to age: 18-29 years, 30-39 years, 40-49 years, and 50-60 years. Maximal muscle strength of the cervical spine was measured using a Lafayette® handheld dynamometer for flexion, extension, and bilateral lateral flexion. No differences in cervical muscle strength were observed among the groups (p > 0.05). However, the 18-29-year-old group took less time to reach the peak of force for flexion than the 50-60-year-old group. Moderate correlations were observed between cervical flexor strength and weight, body mass index, and neck circumference, and between cervical extensor strength and weight and body mass index (r = 0.43-0.55; p < 0.05). Reference values for cervical muscle strength in healthy women were established using a handheld dynamometer, and the association between muscle strength and anthropometric data was moderate.

Neck Strength Evaluated With Fixed and Portable Dynamometers in Asymptomatic Individuals: Correlation, Concurrent Validity, and Agreement

OBJECTIVE

The purpose of this study was to assess the correlation, concurrent validity, and agreement between the isometric cervical force measurements obtained with fixed and portable dynamometers in asymptomatic individuals.

METHODS

Fifty asymptomatic individuals performed 3 maximal isometric contractions for flexion, extension, and lateral flexion of the cervical spine using fixed and portable dynamometers. The correlation and concurrent validity for the measurements of the portable and fixed dynamometers were analyzed using Spearman's correlation coefficient and the intraclass correlation coefficient (ICC), respectively. The agreement between the force values of the portable and fixed dynamometers was measured using the Bland-Altman method.

RESULTS

Isometric cervical force measurements obtained with the fixed dynamometer and portable dynamometer showed a moderately to highly significant correlation for flexion (r_s = 0.74), extension (r_s = 0.82), right lateral flexion (r_s = 0.74), and left lateral flexion (r_s = 0.68). The concurrent validity was moderate to good for all measurements (ICC_2,3 = 0.67-0.80). The fixed and portable dynamometers did not agree, with a significant mean difference between the methods of 2.8 kgf (95% confidence interval [CI], 2.1-3.4 kgf) for cervical flexion, 5.3 kgf (95% CI, 4.2-6.4 kgf) for extension, and 9.1 kgf (95% CI, 0.4-2.1 kgf) for left lateral flexion. The limits of agreement were broad for all movements, with errors that varied between 61% and 77% of the mean force obtained with the fixed dynamometer.

CONCLUSION

The neck strength measurements obtained with the fixed and portable dynamometers demonstrated high to moderate correlation and had moderate to good comparability for asymptomatic participants. However, they did not agree in that the 2 methods did not provide equivalent measurements, and, therefore, based on these findings, the same equipment should always be used when reassessing an individual.

Reliability and difference in neck extensor muscles strength measured by a portable dynamometer in individuals with and without chronic neck pain

OBJECTIVE

There are limited reports about the reliability of measuring neck extensor muscle strength using a portable dynamometer in neck pain patients. The aims of the current study were 1) to investigate intra- and inter-rater reliability of neck extensor isometric strength measurement using a portable dynamometer in patients with chronic nonspecific neck pain (CNSNP) and 2) to compare neck extensor isometric strength in participants with and without CNSNP.

METHODS

Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were followed. Two examiners received a 15-minute training before enrollment. Inter-rater reliability was assessed with a 10-minute interval between measurements, and intra-rater reliability was assessed with a 10-day interval. Three trials were assessed and examiners were blind to the strength values (in Newtons) from other sessions of 20 individuals with CNSNP (mean±SD= 37.9 ± 9.8y; Neck Disability Index 29.2 ± 7.4%) and 20 individuals with other musculoskeletal disorders (mean ± SD = 32.8 ± 46.2y).

RESULTS

Intra-rater reliability was excellent with intraclass correlation coefficient (ICC)(3,1) of 0.95 (CI:0.90-0.97) and inter-rater reliability was good to excellent with ICC(2,1) of 0.88 (CI:0.77-0.94) in CNSNP. No significant difference of neck extensor strength was found between CNSNP (93.27N±31.94) and Individuals without CNSNP (111.43N±40.11) (p > 0.05).

CONCLUSION

A portable dynamometer is a reliable tool for measuring maximal isometric neck extension strength in individuals with CNSNP. Slightly but no significant differences of neck extensor strength values between individuals with and without CNSNP. Future studies are needed to assess the generalizability of the findings in patients with other muscle deconditioning.

Neck-specific strengthening exercise compared with placebo sham ultrasound in patients with migraine: a randomized controlled trial

BACKGROUND

Migraine patients have musculoskeletal disorders and pain in the cervical. And, despite the pathophysiology demonstrating the relationship between migraine and the cervical spine, the effectiveness of craniocervical exercises in these patients has not been verified. So, the aimed of this study was verify the effectiveness of craniocervical muscle-strengthening exercise (CMSE) in reducing the frequency and intensity of headache in migraine patients.  METHODS: A two-armed, parallel-group randomized controlled trial with a 3-month follow-up was performed. For eight weeks, the volunteers in the intervention group (n = 21) performed a protocol of CMSE, while those in the sham ultrasound group (n = 21) received the application of disconnected therapeutic ultrasound in the upper trapezius and guideline for home-stretching. The primary outcomes were the frequency and intensity of the headache. The secondary outcomes were questionnaires about migraine and neck disability, and satisfaction with the treatment, cervical range of motion, the pressure pain threshold, craniocervical flexion test (CCFT), cervical muscle strength and endurance test, and the cervical muscle activity during the physical tests.

RESULTS

No differences were observed for the changes observed in primary outcomes after eight weeks and at the 3-months follow up (p > 0.05). For the secondary outcomes, craniocervical exercises improved the sensitivity of the frontal muscle (p = 0.040) and promoted a reduced amplitude of muscle activity of the anterior scalene and upper trapezius in the last stages of CCFT (p ≤ 0.010). There was also reduced muscle activity of the anterior scalene and splenius capitis in the endurance test (p ≤ 0.045), as evaluated by surface electromyography.

CONCLUSION

CMSE were insufficient in reducing the frequency and intensity of headache, improving the performance of the cervical muscles, or reducing migraine and neck pain-related disabilities. This was found despite a decreased electromyographic activity of the cervical muscles during the last stages of CCFT and increased median frequency during the endurance test.

TRIAL REGISTRATION

Accession code RBR-8gfv5j , registered 28/11/2016 in the Registro Brasileiro de Ensaios Clínicos (ReBEC).

Differentiating migraine, cervicogenic headache and asymptomatic individuals based on physical examination findings: a systematic review and meta-analysis

BACKGROUND

Migraine and cervicogenic headache (CGH) are common headache disorders, although the large overlap of symptoms between them makes differential diagnosis challenging. To strengthen differential diagnosis, physical testing has been used to examine for the presence of musculoskeletal impairments in both conditions. This review aimed to systematically evaluate differences in physical examination findings between people with migraine, CGH and asymptomatic individuals.

METHODS

The databases MEDLINE, PubMed, CINAHL, Web of Science, Scopus, EMBASE were searched from inception until January 2020. Risk of bias was assessed with the Downs and Black Scale for non-randomized controlled trials, and with the Quality Assessment of Diagnostic Accuracy Studies tool for diagnostic accuracy studies. When possible, meta-analyses with random effect models was performed.

RESULTS

From 19,682 articles, 62 studies were included in this review and 41 were included in the meta-analyses. The results revealed: a) decreased range of motion [°] (ROM) on the flexion-rotation test (FRT) (17.67, 95%CI:13.69,21.65) and reduced neck flexion strength [N] (23.81, 95%CI:8.78,38.85) in CGH compared to migraine; b) compared to controls, migraineurs exhibit reduced flexion ROM [°] (- 2.85, 95%CI:-5.12,-0.58), lateral flexion ROM [°] (- 2.17, 95% CI:-3.75,-0.59) and FRT [°] (- 8.96, 95%CI:-13.22,-4.69), reduced cervical lordosis angle [°] (- 0.89, 95%CI:-1.72,-0.07), reduced pressure pain thresholds over the cranio-cervical region [kg/cm²], reduced neck extension strength [N] (- 11.13, 95%CI:-16.66,-5.6) and increased activity [%] of the trapezius (6.18, 95%CI:2.65,9.71) and anterior scalene muscles (2.87, 95%CI:0.81,4.94) during performance of the cranio-cervical flexion test; c) compared to controls, CGH patients exhibit decreased neck flexion (- 33.70, 95%CI:-47.23,-20.16) and extension (- 55.78, 95%CI:-77.56,-34.00) strength [N].

CONCLUSION

The FRT and neck flexion strength could support the differential diagnosis of CGH from migraine. Several physical tests were found to differentiate both headache types from asymptomatic individuals. Nevertheless, additional high-quality studies are required to corroborate these findings.

STUDY REGISTRATION

Following indications of Prisma-P guidelines, this protocol was registered in PROSPERO on 21/05/2019 with the number CRD42019135269 . All amendments performed during the review were registered in PROSPERO, indicating the date and what and why was changed.

Reliability and Validity of Clinical Tests for Measuring Strength or Endurance of Cervical Muscles: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the reliability and validity of clinical tests for measuring cervical muscle strength or endurance in participants with and without neck pain.

DATA SOURCE

Systematic review and meta-analysis on reliability and validity. Literature search was conducted on January 28, 2020, using 5 databases: MEDLINE, Cumulative Index to Nursing and Allied Health, EMBASE, SPORTDiscus, and Scopus.

STUDY SELECTION

We included studies that investigated the reliability or validity of clinical tests for measuring cervical muscle strength or endurance in participants with nonspecific chronic neck pain, with or without irradiation, or healthy participants. We included only those that were viable for daily practice and of low cost.

DATA EXTRACTION

Data were extracted as follows: (1) author and year of publication, (2) demographic values and health condition, (3) reported clinical tests, (4) inclusion and exclusion criteria, (5) description of test, (6) interrater reliability, and (7) intrarater reliability. For validity studies we also extracted the (8) reference method and (9) validity estimates.

DATA SYNTHESIS

Methodological quality was assessed with the Quality Appraisal of Diagnostic Reliability and the Guidelines for Reporting Reliability and Agreement Studies. Data on reliability and validity were extracted from included articles and then analyzed.

RESULTS

Thirty-one studies were included. Cervical flexor and extensor endurance test, craniocervical flexion test (CCFT), AND cervical muscle strength using a handheld dynamometer (HHD) showed moderate to good intra- and interrater reliability (intraclass correlation coefficients ranging from 0.64-0.90). Concurrent validity was measured by only 2 studies, which do not provide adequate evidence for a recommendation.

CONCLUSIONS

The cervical flexor and extensor endurance tests, CCFT, and HHD for measuring cervical strength presented an acceptable interrater and intrarater reliability.

Neck-specific strengthening exercise compared with sham ultrasound when added to home-stretching exercise in patients with migraine: study protocol of a two-armed, parallel-groups randomized controlled trial

BACKGROUND

Migraine is a highly disabling condition and pharmacological treatment is the gold standard. However, several patients have also positive responses to the application of different manual techniques and therapeutic exercises in terms of reducing the intensity and frequency of migraine attacks. Nevertheless, the effects of a neck-specific exercise program have not yet been evaluated in these patients.

OBJECTIVE

To determine the effectiveness of a neck-specific exercise program in reducing the intensity and frequency of migraine attacks as compared to a sham ultrasound group.

METHODS

A two-armed, parallel-groups randomized controlled trial with 3 months of follow-up will be conducted. 42 individuals, both genders, aged between 18 and 55 years old with a medical diagnosis of migraine will be included. The intervention group will perform a protocol consisting of exercises for strengthening the muscles of the cervical spine. Participants within the sham ultrasound group will receive detuned ultrasound therapy in the upper trapezius muscle. Both groups will receive a weekly session for 8 weeks. The efficacy of each intervention will be measured by the frequency and intensity of migraine at a 3-months follow-up.

TRIAL REGISTRATION

This study was registered under access code RBT-8gfv5j in the Registro Brasileiro de Ensaios Clínicos (ReBEC) in November 28, 2016.

CONCLUSION

This study will aim to determine the efficacy of a neck-specific exercise program in reducing the frequency and intensity of migraine attacks. If the results show that a neck-specific exercise program is effective in reducing the frequency and intensity of migraine attacks, therapists will have a low cost and easily applicable tool to treat migraine.