Examining the association between objective physical activity and momentary pain: a systematic review of studies using ambulatory assessment

Chronic pain (CP) is a debilitating and increasingly common health condition that adversely impacts function, including physical activity (PA). Research using ambulatory assessment (AA) methods (e.g., ecological momentary assessment, actigraphy) offers promise for elucidating the relationship between momentary pain and objective PA in CP populations. This study aimed to systematically review articles assessing the association between momentary pain and PA in adults with CP as measured using AA and to make recommendations for the measurement and study of this relationship. Five databases were systematically searched, and 13 unique records (N = 768) met inclusion criteria. CP conditions included mixed/nonspecific CP (k = 3), low back pain (k = 2), fibromyalgia (k = 1), unspecified arthritis (k =1), and hip/knee osteoarthritis (k = 6). Average age of participants across studies was 55.29 years and the majority identified as women (60.68%) and White (83.16%). All studies measured objective PA via actigraphy, and momentary pain with either a diary/log or ratings on an actigraph. Studies varied in quantification of PA (i.e., activity counts, step count, moderate-vigorous PA), statistical method (i.e., correlation, regression, multilevel modelling), and inclusion of moderators (e.g., pain acceptance). Studies reported mixed results for the pain-PA relationship. This heterogeneity suggests that no summarizing conclusions can be drawn about the pain-PA relationship without further investigation into its complex nuances. More within-person and exploratory examinations that maximize the richness of AA data are needed. Greater understanding of this relationship can inform psychotherapeutic and behavioral recommendations to improve CP outcomes. PROSPERO registration number: CRD42023389913. Perspective This article presents a systematic review of the literature on the association between momentary pain and physical activity in adults with chronic pain as measured using ambulatory assessment methods. Better understanding this nuanced relationship could help elucidate areas for timely intervention and may inform clinical recommendations to improve CP outcomes.