The role of fear-avoidance beliefs on low back pain-related disability in a developing socioeconomic and conservative culture : a cross-sectional study of a Pakistani population

Background: The relationship of low back pain, the world’s top disabling condition, with functional disability is often explained by the mediation effect of fear, catastrophizing, and psychological distress. These relationships have not been explored within chronic back pain patients from a low socio-economic, predominantly Muslim country. Thus, it was unclear whether previously established pathways would be consistent in Pakistani pain patients to help guide Pakistani clinicians caring for back pain patients. This cross-sectional study translated English versions of questionnaires within the fear-avoidance model into Urdu, tested the clini-metric properties of the Urdu versions for people with chronic low back pain (CLBP) in Pakistan, and performed mediation analysis to investigate pathways of the fear-avoidance model. Methods: Translation of questionnaires was completed in 4 steps using the forward-backward technique, with subsequent analyses for internal consistency (Cronbach’s α), construct validity (Pearson’s r-value), and test–retest reliability (ICC r-value). Multiple mediation analysis with bootstrapping was performed to analyze pathways within the fear-avoidance model from the Urdu translated questionnaires. Results: A total of 151 people from Pakistan with CLBP completed the questionnaires, with good results for internal consistency (r > 0.85), convergent validity (r > 0.59), and test–retest reliability (ICC r > 0.85). The association of pain with disability was significant (B=2.36, r2 = 0.19, p = 0.19, p<0.001, and the indirect effect of the mediators explained 81% of pain intensity’s total effect on disability. All mediators, apart from physical activity-related fear-avoidance beliefs, were significant mediators of the effect of pain intensity on disability. Conclusion: The Urdu versions of the fear-avoidance questionnaires show good clini-metric properties for use in clinical settings and research in Pakistan. These analyses support existing data for the mediation effect of catastrophizing, psychological distress, and self-efficacy on pain-related disability, and extends these findings to suggest that fear about work may be more important in a relatively lower socioeconomic sample of pain patients

Reductions in movement-associated fear are dependent upon graded exposure in chronic low back pain : an exploratory analysis of a modified 3-item fear hierarchy

Objective: To explore the effectiveness of a modified fear hierarchy on measuring improvements in movement-associated fear in chronic low back pain. Methods: A modified 3-item fear hierarchy was created and implemented based on principles of graded exposure. This study was an exploratory analysis of the modified 3-item fear hierarchy from a larger clinical trial data set. Both groups received pain education and exercise, either bodyweight or strength training. Both groups performed item one on the hierarchy, the squat. Only the strength training group performed item 2, the deadlift. Neither group performed item 3, the overhead press. Analysis of Covariance and stepwise linear regression were used to explore results. Results: Improvement in movement-associated fear was conditional upon graded exposure. Both groups improved in the squat movement (p ≤ 0.05), which both performed. Only the strength training group improved in the deadlift (p ≤ 0.01), and neither improved in the overhead press (p ≥ 0.05). Conclusion: Reductions in movement-associated fear are conditional upon graded exposure, based on the use of a novel modified 3-item fear hierarchy. Further research is needed to understand the utility of this tool in a patient-led approach to co-designing a graded exposure-based intervention

Electromyographic analysis of upper body, lower body, and abdominal muscles during advanced Swiss ball exercises

Although there is now some evidence examining the use of a Swiss ball during core stability and resistance exercises, this has commonly been performed using basic or isometric exercises. There is currently no evidence examining more advanced Swiss ball exercises. The purpose of this study was to determine whether or not muscle activity measured during advanced Swiss ball exercises was at an approximate intensity recommended for strength or endurance training in advanced, or novice individuals. After a familiarization session, 14 recreationally active subjects performed 6 different "advanced" Swiss ball exercises in a randomized order. The primary dependent variables in this study were the activity levels collected from anterior deltoid, pectoralis major, rectus abdominis (RA), external obliques, lumbar erector spinae, vastus lateralis (VL), and biceps femoris using surface electromyography. All signals were normalized to maximal voluntary isometric contractions performed before testing for each muscle. The results of this study showed that the Swiss ball roll elicited muscle activity in triceps brachii (72.5+/-32.4%) and VL (83.6+/-44.2%) commensurate with the intensity recommended for strength exercises in advanced trainers. Rectus abdominis activity was greatest during the bridge exercise (61.3+/-28.5%, p<or=0.01). This was the only exercise to elicit RA muscle activity commensurate with a strength training effect. The remainder of the exercises elicited abdominal activity that would require a higher number of repetitions to be performed for an endurance training adaptation. Although this study has provided evidence for one advanced Swiss ball exercise providing a significant whole-body stimulus, the practical difficulty and risks of performing these more complicated Swiss ball exercises may outweigh potential benefits

Delayed abdominal muscle onsets and self-report measures of pain and disability in chronic low back pain

Objective: The objective of this study was the measure the onset time of the transverse abdominis (TA) muscle during rapid unilateral shoulder movements in individuals with chronic low back pain (LBP), and to evaluate the relationship between latency times and self-report measures of pain and disability. Design: Descriptive cross-sectional study. Setting: University laboratory. Participants: Eighty individuals with chronic LBP of a non-specific origin (males n = 44, females n = 36). Main outcome measures: Responses of the right and left surface TA/internal obliques were measured using surface electromyography (EMG) during rapid unilateral shoulder flexion, abduction, and extension. Pain intensity was measured using a visual analog scale (VAS), and disability with the Oswestry disability index (ODI). Results: Seventy-five percent of individuals were identified as lacking feedforward activation. A significant side × direction main effect was identified, with the ipsilateral latency more delayed in flexion and abduction (F(2316) = 58.2, p < 0.001). Individuals without feedforward activation had lower ODI scores (23.2 ± 6.9% vs 31.0 ± 9.2%, mean difference 7.8%, 95% CI 3.9 to 11.6%, p < 0.001). Regression analysis found that 17% of the variance in VAS scores for the entire sample (n = 80) were explained by the latency times measured. This relationship was stronger when the sample was separated into individuals who did (n = 20), and did not (n = 60) have feedforward activation. Conclusion: Deep abdominal muscle onsets during rapid limb movement were significantly associated with self-rated pain scores. Seventy-five percent of individuals with chronic non-specific LBP exhibited delayed activation. No evidence has been provided in this study to support, or refute the use of specific localized deep abdominal contractions for exercise rehabilitation programs

Muscle activation changes after exercise rehabilitation for chronic low back pain

Objective: To investigate the changes in 2 electromyographic measures, flexion relaxation (FR) response and feed-forward activation of the deep abdominals, associated with low back pain (LBP) after different rehabilitation interventions. Design: A 2×2 factorial design with subjects' self-selecting treatment with randomization after 4 weeks to either the specific exercise group or exercise advice group for a further 12-week period. Setting: General community practitioners and university training center. Participants: Subjects with chronic nonspecific LBP were recruited for this study. A total of 112 people were initially screened, and 60 were recruited for the study, with 50 being available for long-term follow-up. Intervention: Four weeks of treatment (manipulative or nonmanipulation) and 12 weeks of subsequent exercise (supervised Swiss ball training or exercise advice). Main Outcome Measures: The Oswestry Disability Index, FR response measured at T12-L1 and L4-5, and feed-forward activation of the deep abdominal muscles. Results: More rapid improvements in disability were identified for subjects who received the supervised exercise program. The FR response at L4-5 also increased more for those who received directly supervised exercise. Long-term follow-up showed that there was still a between-group difference in the FR response, despite no difference in self-rated disability. Long-term changes were observed for the feed-forward activation of the deep abdominals; however, no exercise or treatment effects were identified. Conclusions: Supervised exercise rehabilitation leads to more rapid improvements in self-rated disability, which were associated with greater improvement in the low back FR response

Acute effect of labile surfaces during core stability exercises in people with and without low back pain

Objective: The purpose of this study was to measure trunk muscle activity, whole body balance, and lumbar range of motion during core stability exercises in individuals with and without low back pain (LBP) on and off a labile surface. Design: Descriptive cross-sectional study. Setting: University laboratory. Participants: Ten individuals with chronic non-specific LBP and 10 matched control subjects. Main outcome measures: Bilateral trunk muscle activity was measured using surface electromyography (EMG); whole body balance was measured by quantifying the dispersion of the centre of pressure (CoP); lumbar range of motion (LROM) was measured with single-axis inclinometers. Results: Individuals with LBP had adaptive recruitment patterns during the side-bridge and modified push-up exercises. CoP dispersion and LROM were not different between groups for any exercise. The labile surface did not change the difference between groups, and only increased muscle activity during the side-bridge (p<0.05). The labile surface increased LROM (p=0.35) and CoP dispersion (p<0.001) during the quadruped, decreased LROM during squats (p = 0.05), and increased CoP dispersion during push-ups (p=0.04). Conclusion: Individuals with LBP exhibited adaptive trunk muscle activity levels while maintaining similar levels of balance and lumbar movement to healthy controls. Since research suggests no one mode of exercise is more beneficial in LBP rehabilitation, the practicality and safety of labile surfaces for LBP exercise rehabilitation must be questioned from this study

Self-report measures best explain changes in disability compared with physical measures after exercise rehabilitation for chronic low back pain

Study Design. Sixteen-week intervention for chronic patients with low back pain (LBP) with 9-month follow-up. Primary randomization at 4 weeks into either supervised Swiss ball exercise or an exercise advice group. Objective. To evaluate changes in disability and pain in individuals with chronic LBP after combined treatment and exercise interventions, and to evaluate whether changes in self-report or physical measures would best explain improvements in disability. Summary of Background Data. There is a need to understand what the effectiveness of a clinically applicable treatment intervention is for an individual’s perception of their back pain. There is insufficient evidence about the different combinations of manual treatment that commonly precede involvement in exercise programs. Methods. Sixty individuals with chronic nonspecific LBP (at least 3-month duration) were randomly assigned (after 4 weeks of manipulative or nonmanipulative treatment) to either a supervised Swiss ball exercise group, or an advice group. The exercise intervention was for 12 weeks with a long-term follow-up of 9 months. Self-report measures and physical measures (endurance times and myoelectric fatigue) were collected throughout the study. Results. Self-rated disability improved more after the treatment period for individuals who received supervised exercise compared with advice alone. There was no difference found between individuals who received manipulative or nonmanipulative treatment. Multiple regression analysis found that self-report measures best explained improvements in disability throughout the study. Long-term findings showed no group differences. Conclusion. Supervised exercise is a more successful subsequent to manual treatment compared with exercise advice. The improvements associated with this type of program were primarily manifested in the psychologic self-report measures rather than physical measurements

Buy-in for back pain : does individualization matter?

Background: The aim of this study was to investigate the effect of individualization of an exercise program on the buy-in received from chronic low back pain (CLBP) patients. Methods: Participants were randomized to 8 weeks of an individualized (IEP) or general exercise program (GEP). All participants were required to attend one 1:1 session per week with an exercise physiologist and 4 home-based sessions. Clinical outcomes were assessed with the Oswestry Disability Index (ODI) and visual analog pain scale (VAS) measured before and after the 8-week intervention along with barrier self-efficacy and adherence. Additionally, multidimensional outcome expectations, exercise self-efficacy, and intention to exercise were measured before the intervention, after the first session, and after 8 weeks. Measures were taken after the first session to observe if clinical assessment and informing the patient that the program was individualized manipulated beliefs differently compared to providing a GEP. Beliefs about the program after the first session were elevated in both groups. Results: Adherence to the supervised and home-based sessions was high and similar between groups. Clinical outcome measures were similar with both groups showing significant reduction from baseline in the ODI (P ≤ 0.01). Conclusion: Thus, it appears an individualized program is no more beneficial than a GEP for CLBP. Clinically, it appears a GEP is an intelligent choice for practitioners as it negates the need for clinical assessments, which appear to add no benefit to outcomes or adherence

Core stability exercises in individuals with and without chronic nonspecific low back pain

The aim of this study was to measure trunk muscle activity during several commonly used exercises in individuals with and without low back pain (LBP). Abdominal bracing was investigated as an exercise modification that may increase the acute training stimulus. After an initial familiarization session, 10 patients with LBP and 10 matched controls performed 5 different exercises (quadruped, side bridge, modified push-up, squat, shoulder flexion) with and without abdominal bracing. Trunk muscle activity and lumbar range of motion (LROM) were measured during all exercises. Muscle activity was measured bilaterally during each exercise from rectus abdominis (RA), external obliques (EO), and lumbar erector spinae (ES) with pairs of surface electrodes. Recorded signals were normalized to a percentage of maximal voluntary contractions performed for each muscle. The ES activity was lower for the LBP group during the quadruped (p < 0.05) and higher for RA and EO during the side bridge (p < 0.001), compared to for the healthy controls. Higher muscle activity was observed across exercises in an inconsistent pattern when abdominal bracing was used during exercise. The LROM was no different between groups for any exercise. The lack of worsening of symptoms in the LBP group and similar LROM observed between groups suggest that all exercises investigated in this study are of use in rehabilitating LBP patients. The widespread use of abdominal bracing in clinical practice, whether it be for patients with LBP or healthy individuals, may not be justified unless symptoms of spinal instability are identified. © 2011 National Strength and Conditioning Association

Does a 'tight' hamstring predict low back pain reporting during prolonged standing?

The purpose of this study was to investigate the relationship between hamstring passive stiffness and extensibility in asymptomatic individuals with the reporting of low back pain during 2-h prolonged standing. Twenty healthy participants with no history of low back pain (mean±SD, age 22.6±2.7years, height 1.74±0.09m, weight 76.2±14.8kg). Low back pain (VAS score; mm) was continuously monitored during 2-h prolonged standing. Hamstring extensibility, passive stiffness, and stretch tolerance were measured before and after prolonged standing using an instrumented straight leg raise (iSLR). Ten participants reported a clinically relevant increase (Δ VAS > 10mm) in low back pain during prolonged standing. Hamstring extensiblity (leg°max), passive stiffness (Nm.°-1), and stretch tolerance (VAS; mm) were no different between pain developers and non-pain developers. No changes in hamstring measures were observed following 2-h prolonged standing. No relationship was observed in this study between measures of hamstring extensibility and the reporting of low back pain during prolonged standing. There is no evidence to recommend hamstring extensibility interventions (i.e. passive stretching) as a means of reducing pain reporting in occupations requiring prolonged standing