Central sensitization plays an important role in most chronic musculoskeletal pain problems; however, evidence of its importance in non-traumatic neck pain is mixed. This systematic review and meta-analysis examined the evidence for central sensitization in people with non-traumatic neck pain and the relationship between central sensitization measures, demographics and pain-related characteristics. Studies reporting case-control differences in hyperalgesia at non-painful remote sites, temporal summation, conditioned pain modulation
and exercise-induced analgesia efficacy were reviewed. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) between people with non-traumatic neck pain and controls were calculated using random effects models when appropriate. Associations between
SMDs with demographics and pain-related characteristics were explored using meta regression. 
Twenty-five studies were eligible with 23 included for meta-analysis. The SMD was moderate for remote mechanical hyperalgesia between people with non-traumatic neck pain regardless of disability levels and controls [sample size (n) = 1195, SMD: -0.65 (-0.84, -0.46)], and large between those with moderate/severe disability and controls [n=132, SMD: -
0.90 (-1.28, -0.53)] (high quality of evidence). The SMDs of remote mechanical hyperalgesia were negatively associated with age (R2=45.6%, P=0.010). There was very low to low quality of evidence for remote cold [n=177, SMD: -0.51 (-0.89, -0.14)] and heat hyperalgesia [n=177, SMD: -0.37 (-0.70 to -0.05)] and dysfunctional conditioned pain modulation [n=129, SMD: -0.36 (-0.72, -0.01)] in people with non-traumatic neck pain. Evidence from this review suggests that central sensitization is present in people with non-traumatic neck pain and may be associated with disability levels and age.

08 - CENTRAL SENSITIZATION IN PEOPLE WITH NON-TRAUMATIC NECK PAIN: SYSTEMATIC REVIEW AND META-ANALYSIS OF OBSERVATIONAL STUDIES