Effect of long-term cervical extensor exercise program on functional disability, pain intensity, range of motion, cervical muscle mass and cervical curvature in young population with chronic non-specific neck pain: a randomized controlled trial

Abstract Background: There is growing popularity of chronic non-specific neck pain (CNNP) in young population. This study aimed to compare the effects of long-term specific cervical extensors training and stretching exercise on improving this chronic disorder in young population. Methods: This is a prospective, randomized, controlled study. We assigned 70 young young participants, 18 to 35 years of age, who suffered CNNP and had loss of cervical lordosis, to undergo either specific cervical extensor training (observation group) or stretching exercise (control group). The duration of exercise was designed to be 12 months. Outcome assessment involved the changes in neck disability index (NDI), visual analogue scale (VAS) from baseline, cervical range of motion (CROM), cross-sectional areas (CSAs) of cervical extensors, and cervical curvature from baseline. The outcome measures were compared between groups at 3-, 6- and 12-month after follow-up. Results: 70 participants underwent randomization. No significant difference of demographics and baseline data between the two groups was found. The observation group had greater improvement in NDI and VAS scores at 12-month follow-up than did the control group. Moreover, greater increase of CROM and CSAs of cervical extensors were found in observation group at 6-month and 12-month follow-up ( P <0.05). More participants in the observation group obtained cervical lordosis at 12-month follow-up, however the difference was marginal, non-significant (P=0.07). Conclusions: Among young population with CNNP, long-term specific cervical extensor training was associated with greater clinically meaningful improvement in disability, pain, and CROM. Increased CSAs of cervical extensors may potentially contribute to recovery of cervical lordosis. Trial registration: The study is registered at the Chinese domestic clinical trial (ChiCTR2000040009) at Chictr.org.The date of registration: November 18, 2020.