Task-Specific Sensitivity in Physical Function Testing Predicts Outcome in Patients With Low Back Pain

Through the Lens of Movement-Evoked Pain: A Theoretical Framework of the "Pain-Movement Interface" to Guide Research and Clinical Care for Musculoskeletal Pain Conditions

Over 120 million Americans report experiencing pain in the past 3 months. Among these individuals, 50 million report chronic pain and 17 million report pain that limits daily life or work activities on most days (ie, high-impact chronic pain). Musculoskeletal pain conditions in particular are a major contributor to global disability, health care costs, and poor quality of life. Movement-evoked pain (MEP) is an important and distinct component of the musculoskeletal pain experience and represents an emerging area of study in pain and rehabilitation fields. This focus article proposes the "Pain-Movement Interface" as a theoretical framework of MEP that highlights the interface between MEP, pain interference, and activity engagement. The goal of the framework is to expand knowledge about MEP by guiding scientific inquiry into MEP-specific pathways to disability, high-risk clinical phenotypes, and underlying individual influences that may serve as treatment targets. This framework reinforces the dynamic nature of MEP within the context of activity engagement, participation in life and social roles, and the broader pain experience. Recommendations for MEP evaluation, encompassing the spectrum from high standardization to high patient specificity, and MEP-targeted treatments are provided. Overall, the proposed framework and recommendations reflect the current state of science in this emerging area of study and are intended to support future efforts to optimize musculoskeletal pain management and enhance patient outcomes. PERSPECTIVE: Movement-evoked pain (MEP) is a distinct component of the musculoskeletal pain experience and emerging research area. This article introduces the "Pain-Movement Interface" as a theoretical framework of MEP, highlighting the interface between MEP, pain interference, and activity engagement. Evaluating and treating MEP could improve rehabilitation approaches and enhance patient outcomes.

Movement-Evoked Pain Versus Widespread Pain: A Longitudinal Comparison in Older Adults With Chronic Low Back Pain From the Delaware Spine Studies

It is currently unknown which pain-related factors contribute to long-term disability and poorer perceived health among older adults with chronic low back pain (LBP). This investigation sought to examine the unique influence of movement-evoked pain (MeP) and widespread pain (WP) on longitudinal health outcomes (ie, gait speed, perceived disability, and self-efficacy) in 250 older adults with chronic LBP. MeP was elicited with 3 standardized functional tests, while presence of WP was derived from the McGill Pain Map. Robust regression with HC3 standard errors was used to examine associations between these baseline pain variables and health outcomes at 12-month follow-up. Covariates for these models included age, sex, body mass index, resting and recall LBP intensity, LBP duration, depression, pain catastrophizing, and baseline outcome (eg, baseline gait speed). Greater MeP was independently associated with worse 12-month LBP-related disability (b = .384, t = 2.013, P = .046) and poorer self-efficacy (b = -.562, t = -2.074, P = .039); but not gait speed (P > .05). In contrast, WP and resting and recall LBP intensity were not associated with any prospective health outcome after adjustment (all P > .05). Compared to WP and resting and recall LBP intensity, MeP is most strongly related to longitudinal health outcomes in older adults with chronic LBP. PERSPECTIVE: This article establishes novel independent associations between MeP and worse perceived disability and self-efficacy at 12-months in older adults with chronic LBP. MeP likely has biopsychosocial underpinnings and consequences and may therefore be an important determinant of health outcomes in LBP and other geriatric chronic pain populations.

Task-based measures of sensitivity to physical activity predict daily life pain and mood among people living with back pain

BACKGROUND

Clinical interventions aim to improve the daily life experiences of patients. However, past research has highlighted important discrepancies between commonly used assessments (e.g. retrospective questionnaires) and patients' daily life experiences of pain. These gaps may contribute to flawed clinical decision-making and ineffective care. Recent work suggests that real-time, task-based clinical assessments may help reduce these discrepancies by adding predictive value in explaining daily life pain experiences. This study aimed to investigate these relationships by evaluating whether task-based measures of sensitivity to physical activity (SPA) predict daily life pain and mood, beyond traditional pain-related questionnaires.

METHODS

Adults with back pain (<6-month onset) answered pain-related questionnaires and completed a standardized lifting task. SPA-Pain, SPA-Sensory and SPA-Mood were, respectively, assessed as task-evoked changes in pain intensity, pressure pain threshold (back, hands), situational catastrophizing. Over the next 9 days, daily life pain and mood were assessed using smartphone-based ecological momentary assessment (EMA-Pain and EMA-Mood, respectively) with stratified random sampling. Data analyses estimated fixed effects (b) using multilevel linear modelling with random intercepts.

RESULTS

Median EMA completion per participant was 66.67% (n = 67 participants). After controlling for covariates, SPA-Pain was associated with EMA-Pain (b = 0.235, p = 0.002) and SPA-Psych approached significance with EMA-Mood (b = -0.159, p = 0.052).

CONCLUSIONS

Task-based assessment of SPA helps explain daily life pain and mood among adults with back pain, beyond traditional questionnaires. Adding task-based assessment of SPA may achieve a more complete picture of pain and mood in daily life, offering clinicians better guidance when prescribing activity-based interventions that are designed to modify daily life behaviour, such as graded activity.

SIGNIFICANCE

This study found that, among people with back pain, task-based measures of sensitivity to physical activity contribute additional predictive value for daily life pain and mood beyond self-report questionnaires. Findings suggest that real-time, task-based measures may help mitigate some of the shortcomings that are commonly associated with retrospective questionnaires.