Why neck pain persists rethinking neck pain recovery through a complex systems approach

Introduction: In patients with acute neck pain, recovery ranges from rapid symptom resolution to persistent pain. Traditional cause-effect reasonings cannot fully explain this heterogeneity, highlighting the need for approaches that capture the dynamic, non-linear nature of recovery.
Purpose: This masterclass proposes understanding neck pain recovery as a dynamic process shaped by interactions among biological, psychological, biophysical, behavioural, and social factors, rather than by any single factor. Using data from a longitudinal study identifying three distinct recovery trajectories, concepts from complex systems theory are applied: feedback loops (reciprocal interactions that can amplify or dampen symptoms), attractor states (stable patterns in which the system settles), control parameters (components that govern to which attractor state the system evolves), attractor landscapes (a map of possible recovery outcomes) and tipping points (thresholds at which small changes of control parameters redirect recovery trajectories). Recovery is conceptualised as emerging from the collective interplay between biopsychosocial components, which can stabilise the system toward either a favourable (low pain) or unfavourable (persistent pain) attractor state.
Implications: A complex systems approach emphasises early identification of patients at risk of persistent pain, pinpointing important control parameters, and timing interventions to disrupt maladaptive feedback loops (i.e., high pain intensity, poor sleep quality, which elevates inflammation and amplifies pain intensity) before they consolidate. Where maladaptive feedback loops dominate, personalised interventions may redirect the system toward recovery; where feedback loops are adaptive, minimal/no intervention may suffice. By recognising recovery as non-linear and influenced by interacting biopsychosocial components, this masterclass gives direction for future research and more effective treatment and prevention of persistent pain.