Pain extent is more strongly associated with disability, psychological factors, and neck muscle function in people with non-traumatic versus traumatic chronic neck pain: a cross sectional study

BACKGROUND: Neck pain is presented with a variety of symptoms. Pain drawings are used in the clinical assessment of people with neck pain. Pain extent based upon pain drawings can be associated with different factors. However, the relation between pain extent and function limitations in people with neck pain is unknown. AIM: The aim of this study was to explore the associations between pain extent extracted from pain drawings, and self-reported neck pain related disability, quality of life, depression, self-reported neck function, cervical muscle function, and range of motion in a chronic neck pain population and possible differences depending on the onset of pain being traumatic or not. DESIGN: Observational cross-sectional study. SETTING: Primary and secondary healthcare. POPULATION: People with chronic neck pain (N.=200) of traumatic (N.=120) or non-traumatic (N.=80) origin. METHODS: Outcome measures: Pain extent, Short Form 36 Health Survey Physical and Mental Component Summary (SF36-PCS/MCS), TAMPA Scale of Kinesiophobia (TSK), Beck Depression Inventory-II (BDI-II), Neck Disability Index (NDI), Craniocervical Flexion Test (CCFT), Cervical Extension Test (CE), and Cervical Range of Motion (ROM). Correlations were calculated using Spearman or Pearson correlation coefficients. Correlation between pain extent and outcomes were calculated for all participants collectively and then separately for those with a traumatic versus non-traumatic neck pain. RESULTS: Overall, significant positive correlations were observed between pain extent and NDI (r=0.33; P<0.001), BDI-II (r=0.29; P<0.001), CCFT (r=-0.24; P=0.001) and CE (r=-0.19; P=0.006). No difference was observed in pain extent between patients with traumatic (mean: 7.6±6.7%) and non-traumatic onset (7.4±6.8%). Pain extent correlated moderately with NDI, BDI-II, TSK, CCFT and CE in those with non-traumatic onset, but weakly with NDI, BDI-II, CCFT and CE in those with trauma-induced chronic neck pain. CONCLUSIONS: Pain extent is correlated with patient-reported neck function, depression and muscle test performance in people with chronic neck pain. These correlations were strongest in those with non-traumatic neck pain. CLINICAL REHABILITATION IMPACT: Patients presenting with larger pain areas show poorer psychological and physical function. Pain drawings can therefore indicate a need for addressing these functions in management of a person with chronic neck pain.