Flexion-relaxation ratio in computer workers with and without chronic neck pain

Author(s)

Pinheiro, Carina Ferreira ^{[1, 2]} ; dos Santos, Marina Foresti ^{[1, 3]} ; Chaves, Thais Cristina ^{[1, 2, 4]}

Affiliation

^[1] Univ Sao Paulo, Ribeirao Preto Med Sch, BR-14049 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Post Grad Program Rehabil & Funct Performance, BR-14049 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Undergrad Program Phys Therapy, BR-14049 Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Dept Neurosci & Behav Sci, BR-14049 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF ELECTROMYOGRAPHY AND KINESIOLOGY; v. 26, p. 8-17, FEB 2016.
• Web of Science Citations: 2

Abstract

This study evaluated the flexion-relaxation phenomenon (FRP) and flexion-relaxation ratios (FR-ratios) using surface electromyography (sEMG) of the cervical extensor muscles of computer workers with and without chronic neck pain, as well as of healthy subjects who were not computer users. This study comprised 60 subjects 20-45 years of age, of which 20 were computer workers with chronic neck pain (CPG), 20 were computer workers without neck pain (NPG), and 20 were control individuals who do not use computers for work and use them less than 4 h/day for other purposes (CG). FRP and FR-ratios were analyzed using sEMG of the cervical extensors. Analysis of FR-ratios showed smaller values in the semispinalis capitis muscles of the two groups of workers compared to the control group. The reference FR-ratio (flexion-relaxation ratio {[}FRR], defined as the maximum activity in 1 s of the re-extension/full flexion sEMG activity) was significantly higher in the computer workers with neck pain compared to the CG (CPG: 3.10, 95% confidence interval {[}CI95%] 2.50-3.70; NPG: 2.33, CI95% 1.93-2.74; CG: 1.99, CI95% 1.81-2.17; p < 0.001). The FR-ratios and FRR of sEMG in this study suggested that computer use could increase recruitment of the semispinalis capitis during neck extension (concentric and eccentric phases), which could explain our results. These results also suggest that the FR-ratios of the semispinalis may be a potential functional predictive neuromuscular marker of asymptomatic neck musculoskeletal disorders since even asymptomatic computer workers showed altered values. On the other hand, the FRR values of the semispinalis capitis demonstrated a good discriminative ability to detect neck pain, and such results suggested that each FR-ratio could have a different application. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 12/24138-9 - Flexion-Relaxation Ratio of Cervical Muscles and Chronic Neck Pain in Workers Office Computer Users
• Grantee: Carina Ferreira Pinheiro de Araújo
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 13/02312-0 - Flexion-Relaxation ratio of neck pain muscles and chronic neck pain in computer office workers
• Grantee: Thaís Cristina Chaves
• Support Opportunities: Regular Research Grants