Bruce F. Walker

The prevalence of low back pain: a systematic review of the literature from 1966 to 1998.

A systematic literature review of population prevalence studies of low back pain between 1966 and 1998 was conducted to investigate data homogeneity and appropriateness for pooling. Fifty-six studies were analyzed using methodologic criteria that examined sample representativeness, data quality, and pain definition. Acceptable studies were assessed for homogeneity and appropriateness for pooling. Thirty were methodologically acceptable. Of these there were significant differences in study design, patient age, mode of data collection, potential temporal effects, and prevalence results. Point prevalence ranged from 12% to 33%, 1-year prevalence ranged from 22% to 65%, and lifetime prevalence ranged from 11% to 84%. A limited number of studies were left for analysis, making the pooling of data difficult. A model using uniform best-practice methods is proposed.

A Consensus Approach Toward the Standardization of Back Pain Definitions for Use in Prevalence Studies

Study Design. A modified Delphi study conducted with 28 experts in back pain research from 12 countries. Objective. To identify standardized definitions of low back pain that could be consistently used by investigators in prevalence studies to provide comparable data. Summary of Background Data. Differences in the definition of back pain prevalence in population studies lead to heterogeneity in study findings, and limitations or impossibilities in comparing or summarizing prevalence figures from different studies. Methods. Back pain definitions were identified from 51 articles reporting population-based prevalence studies, and dissected into 77 items documenting 7 elements. These items were submitted to a panel of experts for rating and reduction, in 3 rounds (participation: 76%). Preliminary results were presented and discussed during the Amsterdam Forum VIII for Primary Care Research on Low Back Pain, compared with scientific evidence and confirmed and fine-tuned by the panel in a fourth round and the preparation of the current article. Results. Two definitions were agreed on a minimal definition (with 1 question covering site of low back pain, symptoms observed, and time frame of the measure, and a second question on severity of low back pain) and an optimal definition that is made from the minimal definition and add-ons (covering frequency and duration of symptoms, an additional measure of severity, sciatica, and exclusions) that can be adapted to different needs. Conclusion. These definitions provide standards that may improve future comparisons of low back pain prevalence figures by person, place and time characteristics, and offer opportunities for statistical summaries.

The test-retest reliability of centre of pressure measures in bipedal static task conditions - A systematic review of the literature

SUMMARY OF BACKGROUND DATA The analysis of centre of pressure (COP) excursions is used as an index of postural stability in standing. Conflicting data have been reported over the past 20 years regarding the reliability of COP measures and no standard procedure for COP measure use in study design has been established. SEARCH METHODS Six online databases (January 1980 to February 2009) were systematically searched followed by a manual search of retrieved papers. RESULTS Thirty-two papers met the inclusion criteria. The majority of the papers (26/32, 81.3%) demonstrated acceptable reliability. While COP mean velocity (mVel) demonstrated variable but generally good reliability throughout the different studies (r=0.32-0.94), no single measurement of COP appeared significantly more reliable than the others. Regarding data acquisition duration, a minimum of 90 s is required to reach acceptable reliability for most COP parameters. This review further suggests that while eyes closed readings may show slightly higher reliability coefficients, both eyes open and closed setups allow acceptable readings under the described conditions (r ≥ 0.75). Also averaging the results of three to five repetitions on firm surface is necessary to obtain acceptable reliability. A sampling frequency of 100 Hz with a cut-off frequency of 10 Hz is also recommended. No final conclusion regarding the feet position could be reached. CONCLUSIONS The studies reviewed show that bipedal static COP measures may be used as a reliable tool for investigating general postural stability and balance performance under specific conditions. Recommendations for maximizing the reliability of COP data are provided.

Hand-held Dynamometry Correlation With the Gold Standard Isokinetic Dynamometry: A Systematic Review

To examine the current evidence regarding the reliability and validity of hand‐held dynamometry for assessment of muscle strength in the clinical setting.

A cochrane review of superficial heat or cold for low back pain

Study Design. Cochrane systematic review. Objective. To assess the effects of superficial heat and cold therapy for low back pain in adults. Summary of Background Data. Heat and cold are commonly used in the treatment of low back pain. Methods. We searched electronic databases from inception to October 2005. Two authors independently assessed inclusion, methodologic quality, and extracted data, using the criteria recommended by the Cochrane Back Review Group. Results. Nine trials involving 1,117 participants were included. In two trials of 258 participants with a mix of acute and subacute low back pain, heat wrap therapy significantly reduced pain after 5 days (weighted mean difference [WMD], 1.06; 95% confidence interval [CI], 0.68–1.45, scale range, 0–5) compared with oral placebo. One trial of 90 participants with acute low back pain found that a heated blanket significantly decreased pain immediately after application (WMD, −32.20; 95% CI, −38.69 to −25.71; scale range, 0–100). One trial of 100 participants with a mix of acute and subacute low back pain examined the additional effects of adding exercise to heat wrap and found that it reduced pain after 7 days. Conclusions. The evidence base to support the common practice of superficial heat and cold for low back pain is limited, and there is a need for future higher-quality randomized controlled trials. There is moderate evidence in a small number of trials that heat wrap therapy provides a small short-term reduction in pain and disability in a population with a mix of acute and subacute low back pain, and that the addition of exercise further reduces pain and improves function. There is insufficient evidence to evaluate the effects of cold for low back pain and conflicting evidence for any differences between heat and cold for low back pain.

Mechanical or inflammatory low back pain: what are the potential signs and symptoms?

Non-specific low back pain (NSLBP) is commonly conceptualised and managed as being inflammatory and/or mechanical in nature. This study was designed to identify common symptoms or signs that may allow discrimination between inflammatory low back pain (ILBP) and mechanical low back pain (MLBP). Experienced health professionals from five professions were surveyed using a questionnaire listing 27 signs/symptoms. Of 129 surveyed, 105 responded (81%). Morning pain on waking demonstrated high levels of agreement as an indicator of ILBP. Pain when lifting demonstrated high levels of agreement as an indicator of MLBP. Constant pain, pain that wakes, and stiffness after resting were generally considered as moderate indicators of ILBP, while intermittent pain during the day, pain that develops later in the day, pain on standing for a while, with lifting, bending forward a little, on trunk flexion or extension, doing a sit up, when driving long distances, getting out of a chair, and pain on repetitive bending, running, coughing or sneezing were all generally considered as moderate indicators of MLBP. This study identified two groups of factors that were generally considered as indicators of ILBP or MLBP. However, none of these factors were thought to strongly discriminate between ILBP and MLBP.

A Cochrane Review of combined chiropractic interventions for low-back pain

Study Design. Cochrane systematic review of randomized controlled trials. Objective. To determine the effects of combined chiropractic interventions on pain, disability, back-related function, overall improvement, and patient satisfaction in adults with low-back pain (LBP). Summary of Background Data. Chiropractors commonly use a combination of interventions to treat people with LBP, but little is known about the effects of this care. Methods. We used a comprehensive search strategy. All randomized trials comparing combined chiropractic interventions (rather than spinal manipulation alone) with no treatment or other therapies were included. At least two authors selected studies, assessed bias risk, and extracted data. Descriptive synthesis and meta-analyses were performed. Results. We included 12 studies involving 2887 LBP participants. Three studies had low risk of bias. Included studies evaluated a range of chiropractic procedures in a variety of subpopulations with LBP. For acute and subacute LBP, chiropractic interventions improved short- and medium-term pain (standardized mean difference [SMD] −0.25 [95% CI: −0.46 to −0.04] and MD −0.89 [95%CI: −1.60 to −0.18]) compared with other treatments, but there was no significant difference in long-term pain (MD −0.46 [95% CI −1.18 to 0.26]). Short-term improvement in disability was greater in the chiropractic group compared to other therapies (SMD −0.36 [95% CI: −0.70 to −0.02]). However, the effect was small and studies contributing to these results had high risk of bias. There was no difference in medium- and long-term disability. No difference was demonstrated for combined chiropractic interventions for chronic LBP and studies that had a mixed population of LBP. Conclusion. Combined chiropractic interventions slightly improved pain and disability in the short term and pain in the medium term for acute/subacute LBP. However, there is currently no evidence that supports or refutes that these interventions provide a clinically meaningful difference for pain or disability in people with LBP when compared to other interventions.

Is there a relationship between pain intensity and postural sway in patients with non-specific low back pain?

BackgroundIncreased center of pressure excursions are well documented in patients suffering from non-specific low back pain, whereby the altered postural sway includes both higher mean sway velocities and larger sway area. No investigation has been conducted to evaluate a relationship between pain intensity and postural sway in adults (aged 50 or less) with non-specific low back pain.MethodsSeventy-seven patients with non-specific low back pain and a matching number of healthy controls were enrolled. Center of pressure parameters were measured by three static bipedal standing tasks of 90 sec duration with eyes closed in narrow stance on a firm surface. The perceived pain intensity was assessed by a numeric rating scale (NRS-11), an equal number of patients (n = 11) was enrolled per pain score.ResultsGenerally, our results confirmed increased postural instability in pain sufferers compared to healthy controls. In addition, regression analysis revealed a significant and linear increase in postural sway with higher pain ratings for all included COP parameters. Statistically significant changes in mean sway velocity in antero-posterior and medio-lateral direction and sway area were reached with an incremental change in NRS scores of two to three points.ConclusionsCOP mean velocity and sway area are closely related to self-reported pain scores. This relationship may be of clinical use as an objective monitoring tool for patients under treatment or rehabilitation.

The Relationship of Lumbar Multifidus Muscle Morphology to Previous, Current, and Future Low Back Pain: A 9-Year Population-Based Prospective Cohort Study

Study Design. Population based prospective cohort study. Objective. We explored the cross-sectional relationships between lumbar multifidus (LM) intramuscular adipose tissue (IMAT) infiltration and low back pain (LBP) at 3 successive time points and investigated the role of IMAT in predicting the occurrence of LBP after 5 and 9 years. Summary of Background Data. Although LBP is a major source of disease burden, the biological determinants of LBP are poorly understood. Methods. Participants were 40-year-old adults randomly sampled from a Danish population and followed up at 45 and 49 years of age. At each time point, participants underwent magnetic resonance imaging and reported ever having had LBP, LBP in the previous year, nontrivial LBP in the previous year, or a history of pain radiating into the legs. Pixel intensity and frequencies from T1-weighted magnetic resonance images identified the greatest proportion of LM IMAT at the L4 and L5 spinal levels. IMAT infiltration was categorized as normal/mild, moderate, or severe based on tertile divisions. Associations were explored with crude and adjusted odds ratios (aORs) from logistic regression models. Model covariates included sex, body mass index, and occupational and leisure time physical activity. Results. A total of 401 participants were enrolled, with 331 (83%) and 286 (71%) participants followed up at 5 and 9 years, respectively. The cross-sectional analyses demonstrated that at the age of 40 years, participants with severe IMAT infiltration demonstrated increased odds of ever experiencing LBP (aOR [95% confidence interval, 95% CI] = 3.16 [1.45–6.89]), nontrivial LBP (aOR [95% CI] = 2.82 [1.36–5.81]), LBP in the past year (aOR [95% CI] = 1.95 [1.07–3.53]), and leg pain (aOR [95% CI] = 2.08 [1.19–3.62]). There were no consistent cross-sectional associations between LBP/leg pain and LM IMAT at 45 or 49 years of age and LM IMAT did not predict future LBP or leg pain. Conclusion. The relationship between LM IMAT and LBP/leg pain is inconsistent and may be modified by age. Level of Evidence: N/A

Chiropractic Observation and Analysis Study (COAST): Providing an understanding of current chiropractic practice

Objectives: COAST (Chiropractic Observation and Analysis Study) aimed to describe the clinical practices of chiropractors in Victoria, Australia.