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

ABSTRACT

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.

KEYWORDS:

• Cervical spine
• neck muscle
• reliability
• dynamometer strength

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

Francis Grondin

Francis Grondin Graduated in Physiotherapy in 2010, PhD candidate at University of La Réunion. His research focuses on cervical radiculopathies diagnosis, neck muscle impairments and treatment of non-specific chronic neck pain individuals

David Colman

David Colman is actually PhD candidte at the University of Liège (ULiège) and assistant professor in the Department of Sport and Rehabilitation Sciences at the University of Liège. He’s working as a half-time physiotherapist in the Spine Center of the Liège University Hospital Center. His thesis research topic concern the contribution to the clinical assessment of neck extensors dysfunctions in neck pain patients.

Nicolas Peyrot

Nicolas Peyrot is full professor of biomechanics at Le Mans University and director of the STAPS (Sciences and Technics of Physical and Sportive Activities) department. After defending his thesis at Saint-Etienne University in 2009, he joined the Reunion University in 2011, then Le Mans University in 2018. His research at the laboratory Motricity, Interactions, Performance (MIP - EA4334) focuses on the study of biomechanical and physiological determinants of motor performance in the fields of sport and health, and integrates the biomechanics of locomotion and muscle physiology.

Olivier Maillard

Olivier Maillard Teacher and researcher in Public Health and Epidemiology, Deputy head of the Center for Clinical Research in Reunion island since 2015. He has participated in the teaching and methodology of diagnostic accuracy studies in the School of Physiotherapy of the Island.

Sébastien Freppel

Dr. Sébastien FREPPEL MD,PhD, Internship and residency in the Nancy University Hospital Chief of the Neurosurgical Department of the Reunion University Hospital (Saint Pierre) since 2013. Skull base surgery, pediatric neurosurgery and spine surgery. Research efforts focused on degenerative cervical spine diseases

Teddy Caderby

Teddy Caderby received his PhD degree in Biomechanics from the University of La Réunion in 2013. He is currently an Assistant Professor at the Department of Physical Activity and Sports Sciences (STAPS) of the University of La Réunion where he primarily teaches Human Biomechanics and Anatomy. His research focuses on human movement and muscle function. His work is aimed mainly at developing non-pharmacological interventions to improve the mobility and quality of life in people with impaired sensorimotor function, such as people with chronic neck pain, the elderly or diabetics.