Background
Neck pain is common in the general population with one-year prevalence varying from 30% to 50%. Globally, neck pain is the fourth leading cause of years lived with disability, which underlines the importance of research to develop effective prevention and treatment programs based on knowledge of underlying mechanisms of neck pain. A recent paper indicates a close connection between alterations in motor control and pain processing in the brain.
Research over the last decade indicates several alterations in neck motor control and sensorimotor entities in subjects with neck pain compared to healthy subjects. Neck pain patients may have delayed onset of deep neck flexors, increased activation of superficial neck flexors, jerky movement patterns, decreased cervical flexor endurance, lower movement velocity, decreased cervical muscle strength, reduced trajectory movement control, irregular and stiffer movement patterns, increased postural sway, and reduced joint position sense. However, no single parameter stands out as representing motor dysfunction in the neck and studies typically use a subset of variables that vary between studies.
Surprisingly, few studies have utilized a comprehensive set of neck movement and motor control tests to contrast patients and healthy subjects. Such comparisons may help identifying specific underlying neck movement or motor control constructs that differentiate patients from healthy subjects. Based on the previous research we decided to group different neck motion and motor control parameters within different constructs of tentative underlying neck motor dysfunction. The aim of this study was thus to compare neck motion and motor control in neck pain patients with moderate to severe neck pain and healthy subjects with tests representing five different constructs: neck flexibility, proprioception, trajectory movement control, head steadiness, and postural sway. Secondary aim was to evaluate the association between clinical features such as pain, disability, and kinesiophobia and the constructs of motor control and neck motion.