Psychosocial Moderators and Mediators of Sensorimotor Exercise in Low Back Pain: A Randomized Multicenter Controlled Trial

Abstract

The effects of exercise interventions on unspecific chronic low back pain (CLBP) have been investigated in many studies, but the results are inconclusive regarding exercise types, efficiency, and sustainability. This may be because the influence of psychosocial factors on exercise induced adaptation regarding CLBP is neglected. Therefore, this study assessed psychosocial characteristics, which moderate and mediate the effects of sensorimotor exercise on LBP. A single-blind 3-arm multicenter randomized controlled trial was conducted for 12-weeks. Three exercise groups, sensorimotor exercise (SMT), sensorimotor and behavioral training (SMT-BT), and regular routines (CG) were randomly assigned to 662 volunteers. Primary outcomes (pain intensity and disability) and psychosocial characteristics were assessed at baseline (M1) and follow-up (3/6/12/24 weeks, M2-M5). Multiple regression models were used to analyze whether psychosocial characteristics are moderators of the relationship between exercise and pain, meaning that psychosocial factors and exercise interact. Causal mediation analysis were conducted to analyze, whether psychosocial characteristics mediate the exercise effect on pain. A total of 453 participants with intermittent pain (mean age = 39.5 ± 12.2 years, f = 62%) completed the training. It was shown, that depressive symptomatology (at M4, M5), vital exhaustion (at M4), and perceived social support (at M5) are significant moderators of the relationship between exercise and the reduction of pain intensity. Further depressive mood (at M4), social-satisfaction (at M4), and anxiety (at M5 SMT) significantly moderate the exercise effect on pain disability. The amount of moderation was of clinical relevance. In contrast, there were no psychosocial variables which mediated exercise effects on pain. In conclusion it was shown, that psychosocial variables can be moderators in the relationship between sensorimotor exercise induced adaptation on CLBP which may explain conflicting results in the past regarding the merit of exercise interventions in CLBP. Results suggest further an early identification of psychosocial risk factors by diagnostic tools, which may essential support the planning of personalized exercise therapy.Level of Evidence: Level I.Clinical Trial Registration: DRKS00004977, LOE: I, MiSpEx: grant-number: 080102A/11-14. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00004977.

Dose–response relationship and effect modifier of stabilisation exercises in nonspecific low back pain: a project-wide individual patient data re-analysis on 1483 intervention participants

“…Although the magnitude of potential effect modifiers influenced the intervention effects, the doseresponse relationships were robust when these further modifiers were considered as covariates. Patients with higher (baseline) pain grades or those with pain killer medication or less depressive symptoms 18,32 showed larger effects, whereas age, blue-collar vs white-collar workers, the total amount of exercise per week, anxiety, perceived social support, and postural control had no, or only a nonsignificant, modifying effect in our sample. Our hypothesis could, thus, be verified.…”

“…Such known effect modifiers are age, the severity of symptoms at baseline, pain medication, motor control deficits, habitual physical activity levels, job demands, perceived social support, social satisfaction, anxiety, and depressive symptomatology. 9,11,18,32 Thus, in order to delineate the role of the dose in exercise, such further potential effect (response) modifiers must also be considered.…”

Machine learning-based identification of determinants for rehabilitation success and future healthcare use prevention in patients with high-grade, chronic, nonspecific low back pain: an individual data 7-year follow-up analysis on 154,167 individuals

“…Numerous known treatment effect moderators, modifiers, and/or prognostic factors of treatment success in low back pain therapies comprise age, gender, habitual physical activity levels, the severity of symptoms at baseline, previous sick leave because of low back pain, motor control deficits, psychological distress, quality of life, perceived social support, social satisfaction, anxiety and depressive symptomatology, job demands, employment status and type, education, socioeconomic status, narcotic medication use, and treatment expectations. 4,5,9,17,20,21,27,29,31,32,41 Many of these prognostic factors could be confirmed in our analysis; some were new, whereas some were not assessed during the monitoring. Most importantly, the direction of the impact of most of these known prognostic factors is not always clear.…”

Stress and Pain. Predictive (Neuro)Pattern Identification for Chronic Back Pain: A Longitudinal Observational Study

“…On the other hand, neuromuscular adaption within the sensorimotor system is, for example, influenced by the neurotransmitter concentration. This reciprocal relationship between exercise, pain and stress ( 49 ) leads to limitations in the explanation of the pain network constellations ( 62 ). Therefore, the results in general may be conflicted or limited by methods or exclusion of important factors (e.g., physical activity/exercising, sleep) ( 59 ).…”