Potential Muscle Biomarkers of Chronic Myalgia in Humans – A Systematic Review of Microdialysis Studies

Approximately 20% of the European population report severe chronic pain (Breivik et al., 2006), with higher prevalences in women and in lower income groups (Gerdle et al., 2004; Larsson et al., 2007). Common chronic pain conditions are localized neck-shoulder pain including trapezius myalgia (prevalence in population 10-20%) (Lidgren, 2008), chronic whiplash associated disorders (WAD) (prevalence in the population 1.5%) (Guez et al., 2002), and chronic widespread pain (CWSP) (prevalence in population 5-10%) (Gerdle et al., 2008a). Chronic pain is associated with disability, low quality of life, and substantial socioeconomic costs (Breivik et al., 2006; Phillips, 2006; SBU, 2006).