Domains of chronic low back pain and assessing treatment effectiveness : a clinical perspective

Nonspecific chronic low back pain (CLBP) is a common clinical condition that has impacts at both the individual and societal level. Pain intensity is a primary outcome used in clinical practice to quantify the severity of CLBP and the efficacy of its treatment; however, pain is a subjective experience that is impacted by a multitude of factors. Moreover, differences in effect sizes for pain intensity are not observed between common conservative treatments, such as spinal manipulative therapy, cognitive behavioral therapy, acupuncture, and exercise training. As pain science evolves, the biopsychosocial model is gaining interest in its application for CLBP management. The aim of this article is to discuss our current scientific understanding of pain and present why additional factors should be considered in conservative CLBP management. In addition to pain intensity, we recommend that clinicians should consider assessing the multidimensional nature of CLBP by including physical (disability, muscular strength and endurance, performance in activities of daily living, and body composition), psychological (kinesiophobia, fear-avoidance, pain catastrophizing, pain self-efficacy, depression, anxiety, and sleep quality), social (social functioning and work absenteeism), and health-related quality-of-life measures, depending on what is deemed relevant for each individual. This review also provides practical recommendations to clinicians for the assessment of outcomes beyond pain intensity, including information on how large a change must be for it to be considered "real" in an individual patient. This information can guide treatment selection when working with an individual with CLBP

High-Frequency, Low-Magnitude Vibration Does Not Prevent Bone Loss Resulting from Muscle Disuse in Mice following Botulinum Toxin Injection

High-frequency, low-magnitude vibration enhances bone formation ostensibly by mimicking normal postural muscle activity. We tested this hypothesis by examining whether daily exposure to low-magnitude vibration (VIB) would maintain bone in a muscle disuse model with botulinum toxin type A (BTX). Female 16–18 wk old BALB/c mice (N = 36) were assigned to BTX-VIB, BTX-SHAM, VIB, or SHAM. BTX mice were injected with BTX (20 µL; 1 U/100 g body mass) into the left hindlimb posterior musculature. All mice were anaesthetized for 20 min/d, 5 d/wk, for 3 wk, and the left leg mounted to a holder. Through the holder, VIB mice received 45 Hz, ±0.6 g sinusoidal acceleration without weight bearing. SHAM mice received no vibration. At baseline and 3 wk, muscle cross-sectional area (MCSA) and tibial bone properties (epiphysis, metaphysis and diaphysis) were assessed by in vivo micro-CT. Bone volume fraction in the metaphysis decreased 12±9% and 7±6% in BTX-VIB and BTX-SHAM, but increased in the VIB and SHAM. There were no differences in dynamic histomorphometry outcomes between BTX-VIB and BTX nor between VIB and SHAM. Thus, vibration did not prevent bone loss induced by a rapid decline in muscle activity nor produce an anabolic effect in normal mice. The daily loading duration was shorter than would be expected from postural muscle activity, and may have been insufficient to prevent bone loss. Based on the approach used in this study, vibration does not prevent bone loss in the absence of muscle activity induced by BTX

Using whole-body vibration for countermeasure exercise

Whole-body vibration exercise has been tested as a countermeasure against deterioration of body systems in spaceflight simulation (bed rest). The first Berlin BedRest Study demonstrated that resistive vibration exercise (RVE) can reduce muscle loss, prevent muscle weakness, prevent bone loss, and ameliorate pain during post–bed rest recovery as well as prevent or reduce changes in other body systems. A limitation of this study was the inability to determine the contribution of WBV in addition to resistance exercise (RE). The second Berlin BedRest Study showed that adding WBV to RE resulted in better efficacy to prevent bone loss, whereas RE and RVE were equivocal in reducing or preventing muscle atrophy. There was some evidence of an additional effect of WBV in modulating body composition changes when added to RE. Successful countermeasure exercise with WBV is possible when performed vigorously, i.e. with large loading force, and with more than three exercise sessions per week

Protection motivation theory screening tool for predicting chronic low back pain rehabilitation adherence: analysis of a randomised controlled trial

OBJECTIVE: To explore a protection motivation theory screening tool for predicting rehabilitation adherence. DESIGN: Analysis of a randomised controlled trial. SETTING: An exercise physiology and physiotherapist clinic. PARTICIPANTS: Patients with chronic low back pain (n=40). INTERVENTIONS: General strength and conditioning (GSC) compared with motor control and manual therapy. Primary and secondary outcome measures: predicting patient adherence to supervised sessions and dropout using the Sports Injury Rehabilitation Beliefs Scale, seven-item barriers checklist and Positive and Negative Affect Schedule and Sports Injury Rehabilitation Adherence Scale. RESULTS: Average attendance was 77% (motor control and manual therapy) and 60% (GSC) with eight dropouts. No Sports Injury Rehabilitation Adherence Scale values other than 5 across all three components were recorded. Treatment efficacy (p=0.019), self-efficacy (p=0.001), rehabilitation value (p=0.028) and injury severity (p=0.002) positively correlated with susceptibility (the extent of vulnerability to having health problems from not taking action). Rehabilitation value positively correlated with self-efficacy (p=0.005). Injury severity positively correlated with rehabilitation value (p=0.011). The final model for number of cancellations included rehabilitation value only and accounted for approximately 12% of variance (p=0.033). CONCLUSIONS: Perceived value of rehabilitation should be considered by clinicians in the rehabilitation setting to improve treatment adherence in patients with chronic low back pain. TRIAL REGISTRATION NUMBER: ACTRN12615001270505

Magnetic resonance imaging assessment of trunk muscles during prolonged bed rest

Study Design. Prospective longitudinal study. Objective. To investigate, using magnetic resonance imaging (MRI), the influence of bed rest on the lumbopelvic musculature. Summary of Background Data. Reduced gravitational loading and inactivity (bed rest) are known to result in significant change in musculoskeletal function, although little is known about its effects on specific muscles of the lumbopelvic region. Methods. Ten healthy male subjects underwent 8 weeks of bed rest with 6 months of follow-up. MRI of the lumbopelvic region was conducted at regular time-points during and after bed rest. Using uniplanar images at L4, cross-sectional areas (CSAs) of the multifidus, lumbar erector spinae, quadratus lumborum, psoas, anterolateral abdominal, and rectus abdominis muscles were measured. Results. Multifidus CSA decreased by day 14 of bed rest (F = 7.4, P = 0.04). The lumbar erector spinae and quadratus lumborum CSA showed no statistically significant difference to baseline across the time of bed rest (P > 0.05). The anterolateral abdominal, rectus abdominis, and psoas CSA all increased over this time. Psoas CSA increased by day 14 (F = 6.9, P = 0.047) and remained so until day 56, whereas the anterolateral abdominal CSA (F = 29.4, P = 0.003) and rectus abdominis CSA (F = 8.9, P = 0.03) were not statistically larger than baseline until day 56. On reambulation after completion of the bed rest phase, multifidus, anterolateral abdominal, and rectus abdominis CSA returned to baseline levels (P > 0.05) by day 4 of follow-up, whereas psoas CSA returned to baseline level after day 28 of the follow-up period. Conclusions. Bed rest resulted in selective atrophy of the multifidus muscle. An increased CSA of the trunk flexor musculature (increases in psoas, anterolateral abdominal, and rectus abdominis muscles) may reflect muscle shortening or possible overactivity during bed rest. Some of the changes resemble those seen in low back pain and may in part explain the negative effects of bed rest seen in low back pain sufferers

Pain sensitivity is reduced by exercise training: Evidence from a systematic review and meta-analysis

BELAVY, D. L., J. Van Oosterwijck, M. Clarkson, E. Dhondt, N. L. Mundell, C. Miller and P. J. Owen. NEUROSCI BIOBEHAV REV 21(1) XXX-XXX, 2020. Exercise training is capable of reducing pain in chronic pain syndromes, yet its mechanisms are less well established. One mechanism may be via the impact of exercise on increasing a person's pain threshold. Here we show, via meta-analysis of fifteen exercise training studies in pain syndromes that exercise training leads to increased pressure pain thresholds (low to moderate quality evidence). We also find low to moderate quality evidence exists that exercise training was more effective than non-exercise interventions, such as pain education, massage and stress management for improving pain sensitivity. Further, the effect of exercise was greater locally at the site of pain and less so at remote regions. These finding suggest that adaptations in central inhibition occur over time with exercise training and, more widely, add to the mechanistic understanding of how effective interventions can improve pain in chronic pain syndromes