Management of acute low back pain in emergency departments in São Paulo, Brazil: a descriptive, cross-sectional analysis of baseline data from a prospective cohort study.

OBJECTIVE: To describe management strategies used in public emergency departments in a middle-income country for patients with acute non-specific low back pain. DESIGN: A descriptive, cross-sectional analysis of baseline data from a prospective cohort study. SETTING AND PARTICIPANTS: A study with 600 patients with low back pain presenting in four public emergency departments from São Paulo, Brazil was conducted. OUTCOME MEASURES: Diagnostic tests, pharmacological interventions, and/or referral to other healthcare professionals were collected. Descriptive analyses were used to report all outcomes. RESULTS: Of all patients, 12.5% (n=75) underwent some diagnostic imaging tests. Medication was administered to 94.7% (n=568) of patients. The most common medications were non-steroidal anti-inflammatory drugs (71.3%; n=428), opioids (29%; n=174) and corticosteroids (22.5%; n=135). Only 7.5% (n=45) of patients were referred to another type of care. CONCLUSION: There is a need for research data on low back pain from middle-income countries. There was an acceptable rate of prescription for diagnostic imaging tests. However, there were high medication prescriptions and small rates of referrals to other healthcare services. Our findings indicate that there is still a need to implement best practices in the management of acute low back pain at public emergency departments in Brazil.

What are the variables associated with Altmetric scores?

BACKGROUND: Social media has been used to disseminate the contents of scientific articles. To measure the impact of this, a new tool called Altmetric was created. Altmetric aims to quantify the impact of each article through online media. This systematic review aims to describe the associations between the publishing journal and published article variables and Altmetric scores. METHODS: Searches on MEDLINE, EMBASE, CINAHL, CENTRAL, and Cochrane Library were conducted. We extracted data related to both the publishing article and the publishing journal associated with Altmetric scores. The methodological quality of included articles was analyzed by the Appraisal Tool for Cross-sectional Studies. RESULTS: A total of 19 articles were considered eligible. These articles summarized a total of 573,842 studies. Citation counts, journal impact factor, access counts, papers published as open access, and press releases generated by the publishing journal were associated with Altmetric scores. The magnitude of these associations ranged from weak to strong. CONCLUSION: Citation counts and journal impact factor are the most common variables associated with Altmetric scores. Other variables such as access counts, papers published in open access journals, and the use of press releases are also likely to be associated with online media attention. SYSTEMATIC REVIEW REGISTRATION: This review does not contain health-related outcomes. Therefore, it is not eligible for registration.

Photobiomodulation therapy is not better than placebo in patients with chronic nonspecific low back pain: a randomised placebo-controlled trial.

ABSTRACT: Photobiomodulation therapy (PBMT) has been used in several musculoskeletal disorders to reduce pain, inflammation, and promoting tissue regeneration. The current evidence about the effects of PBMT on low back pain (LBP) is still conflicting. We aimed to evaluate the effects of PBMT against placebo on pain intensity and disability in patients with chronic nonspecific LBP. This was a prospectively registered, randomised placebo-controlled trial, with blinded patients, therapists, and assessors. The study was conducted on an outpatient physical therapy clinic in Brazil, between April 2017 and May 2019. A total of 148 patients with chronic nonspecific LBP were randomised to either active PBMT (n = 74) or placebo (n = 74). Patients from both groups received 12 treatment sessions, 3 times a week, for 4 weeks. Patients from both groups also received an educational booklet based on "The Back Book." Clinical outcomes were measured at baseline and at follow-up appointments at 4 weeks, 3, 6, and 12 months after randomisation. The primary outcomes were pain intensity and disability measured at 4 weeks. We estimated the treatment effects using linear mixed models following the principles of intention-to-treat. There was no clinical important between-group differences in terms of pain intensity (mean difference = 0.01 point; 95% confidence interval = -0.94 to 0.96) and disability (mean difference = -0.63 points; 95% confidence interval = -2.23 to 0.97) at 4 weeks. Patients did not report any adverse events. Photobiomodulation therapy was not better than placebo to reduce pain and disability in patients with chronic nonspecific LBP.

The impact of low back pain systematic reviews and clinical practice guidelines measured by the Altmetric score: Cross-Sectional study.

BACKGROUND: Although Altmetric has been widely used by researchers to monitor the audience of their articles, there are no studies that have analysed factors associated with Altmetric score for systematic reviews and clinical practice guidelines. OBJECTIVES: 1) To analyse factors that could be associated with Altmetric scores for low back pain systematic reviews and clinical practice guidelines. 2) To describe the characteristics of these articles and their Altmetric scores. METHODS: We searched for all low back pain systematic reviews and guidelines indexed on the Physiotherapy Evidence Database published between 2015 and 2017. We extracted data related to the published paper, the publishing journal, and Altmetric scores. RESULTS: A total of 66 systematic reviews and 5 guidelines were included. The variable impact factor (independent variable) was associated with Altmetric mentioned score (dependent variable) with a ß coefficient of 15.4 (95% CI: 0.97, 29.7) ajusted to all remaining variables. The variable number of citations normalized by year of publication (independent variable) was associated with Altmetric reader score (dependent variable) with a ß coefficient of 6.4 (95% CI: 4.03, 8.72) ajusted to all remaining variables. We also found that the majority of the systematic reviews and guidelines were published in English, had a descriptive title, were published as open access, included multicenter studies, and had media release generated by the publishing journal. CONCLUSION: Metrics related to the number of citations, such as the impact factor are associated with Altmetric scores.

Factors associated with the reporting quality of low back pain systematic review abstracts in physical therapy: a methodological study.

BACKGROUND: Abstracts of systematic reviews (SR) are frequently used to guide clinical decision-making. However, if the abstract is inadequately reported, key information may be missing and it may not accurately summarize the results of the review. OBJECTIVE: We aimed to investigate 1) if abstracts are fully reported; 2) if abstract reporting is associated with review/journal characteristics in physical therapy for low back pain (LBP); and 3) if these abstracts are consistent with the corresponding full texts. METHODS: We searched the Physiotherapy Evidence Database for SRs in physical therapy for LBP published between 2015 and 2017. Associations between abstract reporting quality and review/journal characteristics were explored with linear regression. Abstract reporting was assessed with the 12 item Preferred Reporting Items for Systematic Reviews and Meta-Analyses for abstracts (PRISMA-A) checklist. Consistency of reporting between abstracts and the full text was evaluated by comparing responses to each item of the PRISMA-A using Kappa coefficients. Methodological quality of the reviews was assessed with A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2). RESULTS: We included 66 SRs, 9 Cochrane and 57 non-Cochrane. Review methodological quality ranged from 'high' (8%) to 'critically low' (76%). The mean ± SD of the "total number of PRISMA-A fully reported items" (range 0-12 points for fully reported items) was 4.1 ±â€¯1.9 points for non-Cochrane review abstracts and 9.9 ±â€¯1.1 points for Cochrane abstracts. Factors associated with reporting quality of abstracts were: journal impact factor (ß 0.20; 95% CI: 0.06, 0.35), number of words in abstract (ß 0.01; 95% CI: 0.00, 0.01) and review methodological quality ('critically low' with ß -3.06; 95% CI: -5.30, -0.82; with 'high' as reference variable). There was typically inconsistent reporting between abstract and full text, with most Kappa values lower than 0.60. CONCLUSIONS: The abstracts of SRs in physical therapy for LBP were poorly reported and inconsistent with the full text. The reporting quality of abstracts was higher in journals with a higher impact factor, in abstracts with a greater number of words, and when the review was of higher methodological quality.

Eight in Every 10 Abstracts of Low Back Pain Systematic Reviews Presented Spin and Inconsistencies With the Full Text: An Analysis of 66 Systematic Reviews.

STUDY DESIGN: Overview study. BACKGROUND: Abstracts of systematic reviews have presented 'spin' (i.e. overstated interpretation of study results) and inconsistency with the full text. OBJECTIVES: 1. Do abstracts of low back pain reviews contain spin? 2. Do these abstracts consistently represent the full text? 3. Is abstract spin associated with the type of conclusion? METHODS: We searched the Physiotherapy Evidence Database (PEDro) on 10th January 2018. Data were extracted from systematic reviews of physiotherapy interventions for low back pain, published between 2015 and 2017. Spin was assessed using a 7-item checklist. We evaluated consistency by comparing information contained in the abstract and the full text using the 7-item checklist with Kappa coefficient analysis. We used logistic regression analysis to evaluate the association between spin in the abstract and type of conclusion. We evaluated methodological quality using the AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews). RESULTS: We included 66 eligible systematic reviews, subdivided into Cochrane (n=9) and non-Cochrane (n=57) reviews. There was some form of spin in 80% of abstracts. Abstracts of non-Cochrane reviews were not consistent with the full text (fair to moderate agreement). Cochrane review abstracts had substantial to almost perfect agreement with the full text. Spin was not associated with the type of conclusion in all systematic reviews (P < 0.05). The methodological quality ranged from 'high' to 'critically low'. CONCLUSIONS: The abstracts of systematic reviews evaluating physiotherapy interventions for low back pain need improvement. J Orthop Sports Phys Ther, Epub 23 Aug 2019. doi:10.2519/jospt.2020.8962.

Journal impact factor is associated with PRISMA endorsement, but not with the methodological quality of low back pain systematic reviews: a methodological review.

PURPOSE: To analyze the association of impact factor of the journals publishing low back pain systematic reviews with whether these journals endorsed the PRISMA recommendations and the reviews methodological quality. METHODS: We searched the Physiotherapy Evidence Database on January 2018 for all low back pain systematic reviews, published between 2015 and 2017. Our primary outcomes were PRISMA recommendations endorsement by the journal and 2017 journal impact factor. We assessed systematic review methodological quality using the AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews) and reported descriptive statistics. A multivariate linear regression model was built. We assessed 66 systematic reviews published in 42 journals. Thirty-seven journals had an impact factor (mean 4.0, SD 4.8). 55% journals endorsed the PRISMA recommendations. The methodological quality of 75.8% systematic reviews was critically low. Journals with higher impact factor were associated with journals endorsing the PRISMA recommendations (ß 3.7; 95% CI 1.2, 6.3), but were not associated with the reviews' methodological quality (ß - 0.3; 95% CI - 4.8, 4.3). LIMITATIONS: Our findings may not be generalized to other study populations and interventions such as medical devices, surgery and medication. CONCLUSIONS: Three out of every four published low back pain systematic reviews had critically low methodological quality. Journals with higher impact factor were associated with journals endorsing the PRISMA recommendations. Clinicians must know how to critically appraise reviews. Journals' editorial policies should include the assessment of study methodological quality and reporting in the review process of an article. These slides can be retrieved under Electronic Supplementary Material.

Description of low back pain clinical trials in physical therapy: a cross sectional study.

OBJECTIVE: To describe the main characteristics of low back pain randomized controlled trials on the Physiotherapy Evidence Database, and to rank the journals where these trials were published according to their Impact Factor. METHODS: This is a cross sectional study based on a collection of randomized controlled trials. A random sample of 200 low back pain trials published between 2010 and 2015 were selected from Physiotherapy Evidence Database in February 2016. We collected the following main characteristics of trials: 2015 journal Impact Factor; if the paper was published as open access; CONSORT recommendations endorsement by the journal; methodological quality and statistical reporting measured by the 0-10 items Physiotherapy Evidence Database scale. Data was analyzed descriptively. RESULTS: Trials were published in journals with a mean Impact Factor of 2.5 (SD 2.5), from which 55.5% endorsed the CONSORT recommendations. The methodological quality was moderate with 5.8 points (SD 1.6). The top 3 journals according to Impact Factor were: (1) British Medical Journal; (2) Annals of Internal Medicine; and (3) BMC Medicine. Only 6 out of 97 journals publishing low back pain trials combined the following factors: journal Impact Factor higher than 2.0, mean trial methodological quality higher than 6.0 points, endorse CONSORT recommendations and offering papers as open access. CONCLUSION: Clinicians interested in low back pain trials must look for a wide variety of healthcare journals. A substantial number of low back pain randomized controlled trials did not follow adequate reporting and methodological recommendations.

Reliability of the Mechanical Diagnosis and Therapy System in Patients With Spinal Pain: A Systematic Review.

BACKGROUND: An updated summary of the evidence for the reliability of the Mechanical Diagnosis and Therapy (MDT) system in patients with spinal pain is needed. OBJECTIVE: To investigate the evidence on the intrarater and interrater reliability of MDT in patients with spinal pain. METHODS: Searches in MEDLINE, CINAHL, Embase, PEDro, and Scopus were conducted for this systematic review. We included any study design as long as reliability of the MDT method was tested in patients with spinal pain. We collected data on the reliability of MDT to identify main and subsyndromes, directional preference, the centralization phenomenon, and lateral shift. The methodological quality of studies was assessed using the Quality Appraisal of Diagnostic Reliability and the Guidelines for Reporting Reliability and Agreement Studies checklists. RESULTS: Twelve studies were included (8 studies on back pain, pooled n = 2160 patients; 3 studies on neck pain, pooled n = 45 patients; and 3 studies recruited mixed spinal conditions, pooled n = 389 patients). Studies investigating patients with back pain reported kappa estimates ranging from 0.26 to 1.00 (main and subsyndromes), 0.27 to 0.90 (directional preference), and 0.11 to 0.70 (centralization phenomenon). Kappa estimates for studies investigating neck pain ranged from 0.47 to 0.84 (main and subsyndromes) and 0.46 (directional preference). In mixed populations, kappa estimates ranged from 0.56 to 0.96 (main and subsyndromes). CONCLUSION: The MDT system appears to have acceptable interrater reliability for classifying patients with back pain into main and subsyndromes when applied by therapists who have completed the credentialing examination, but unacceptable reliability in other therapists. We found conflicting evidence regarding the reliability of the MDT system in patients with neck pain or mixed pain locations. J Orthop Sports Phys Ther 2018;48(12):923-933. Epub 22 Jun 2018. doi:10.2519/jospt.2018.7876.

Impact of Low Back Pain Clinical Trials Measured by the Altmetric Score: Cross-Sectional Study.

BACKGROUND: There is interest from authors and publishers in sharing the results of their studies over the Internet in order to increase their readership. In this way, articles tend to be discussed and the impact of these articles tends to be increased. In order to measure this type of impact, a new score (named Altmetric) was created. Altmetric aims to understand the individual impact of each article through the attention attracted online. OBJECTIVE: The primary objective of this study was to analyze potential factors related with the publishing journal and the publishing trial that could be associated with Altmetric scores on a random sample of low back pain randomized controlled trials (RCTs). The secondary objective of this study was to describe the characteristics of these trials and their Altmetric scores. METHODS: We searched for all low back pain RCTs indexed on the Physiotherapy Evidence Database (PEDro; www.pedro.org.au) published between 2010 and 2015. A total of 200 articles were randomly selected, and we extracted data related to the publishing trial, the publishing journal, methodological quality of the trials (measured by the 0-10 item PEDro scale), and total and individual scores of Altmetric mentioned and Altmetric reader. The study was a cross-sectional study, and multivariate regression models and descriptive statistics were used. RESULTS: A total of four variables were associated with Altmetric mentioned score: impact factor (ß-coefficient=3.4 points), number of years since publication (ß-coefficient=-4.9 points), number of citations divided by years since publication (ß-coefficient=5.2 points), and descriptive title (ß-coefficient=-29.4 points). Only one independent variable was associated with Altmetric reader score: number of citations divided by years since publication (ß-coefficient=10.1 points, 95% CI 7.74-12.46). We also found that the majority of articles were published in English, with a descriptive title, and published in open access journals endorsing the Consolidated Standards of Reporting Trials (CONSORT) statement. CONCLUSIONS: Researchers should preferably select high impact factor journals for submission and use declarative or interrogative titles, as these factors are likely to increase the visibility of their studies in social media.

Medium term effects of kinesio taping in patients with chronic non-specific low back pain: a randomized controlled trial.

BACKGROUND: Kinesio taping is a commonly used intervention for patients with chronic low back pain. However, the medium term effects of kinesio taping in these patients are unknown. OBJECTIVE: To investigate the effectiveness of kinesio taping in patients with chronic low back pain after 6 months from randomization. METHODS: This was a randomized controlled trial with a 6 months follow up. One hundred and forty eight participants were randomly assigned to the experimental (kinesio taping with skin convolutions) or control (kinesio taping without convolutions-Sham Taping) group. Participants from both groups had the tape reapplied twice a week for four weeks. The outcomes were pain, disability and global impression of recovery after 6 months. RESULTS: One participant was lost to follow up in the experimental group (n=73, response rate 99%) and two in the control group (n=72, response rate 97%). After 6 months there were no statistically significant between-group differences in pain intensity (between-group difference -0.8 points, 95% CI -1.7 to 0.2), global impression of recovery (0.4, -0.7 to 1.5), or disability (-1.1, -3.0 to 0.7). CONCLUSION: Four weeks of kinesio taping treatment was no better than sham taping for patients with chronic low back pain, at 6 months follow-up. Trial Registration Number (http://www.ensaiosclinicos.gov.br/): RBR-7ggfkv (Brazilian Registry of Clinical Trials).

Effects of photobiomodulation therapy in patients with chronic non-specific low back pain: protocol for a randomised placebo-controlled trial.

INTRODUCTION: Low back pain (LBP) is one of the largest and most frequent public health problems worldwide. Photobiomodulation therapy (PBMT) is a frequently used non-pharmacological therapy for the treatment of musculoskeletal disorders. However, there is little high-quality scientific evidence that demonstrates the effectiveness of PBMT in the treatment of patients with chronic LBP in the short, medium and long term. Therefore, the objective of this clinical trial is to evaluate the effects of PBMT in patients with chronic non-specific LBP in the short, medium and long term. METHODS AND ANALYSES: This is a prospectively registered, two-arm randomised placebo-controlled trial with blinded patients, assessors and treatment providers. One hundred and forty-eight patients with chronic non-specific LBP will be recruited. Treatment sessions will be provided three times a week for 4 weeks (totaling 12 sessions) with patients receiving either placebo or active PBMT. For ethical reasons, all patients, regardless of treatment allocation, will also receive an information booklet based on 'The Back Book'. Clinical outcomes will be measured at baseline, at the end of treatment, as well as 3, 6 and 12 months after randomisation. The primary outcomes will be pain intensity and disability measured after 12 sessions of treatment. The secondary outcomes will be pain intensity and disability measured at 3, 6 and 12 months after randomisation, in addition to specific disability and global perceived effect in all time points. ETHICS AND DISSEMINATION: The study was approved by the Research Ethics Committee of Universidade Cidade de São Paulo. The results will be disseminated through scientific publications and presentations at national and international scientific meetings. TRIAL REGISTRATION NUMBER: NCT03089424.

Measurement properties of the Brazilian version of the Working Alliance Inventory (patient and therapist short-forms) and Session Rating Scale for low back pain.

BACKGROUND: In the low back pain (LBP) field, therapeutic alliance is considered a non-specific factor of interventions associated with improvements in clinical outcomes. However, there is a paucity of studies aimed to evaluate measurement properties of tools used to objectively quantify the alliance between therapist and patients, such as the Working Alliance Inventory (WAI) and Session Rating Scale (SRS). OBJECTIVE: To translate and cross-culturally adapt the short-form version of WAI - therapist and SRS into Brazilian Portuguese; to investigate the measurement properties, of the WAI-Patient, WAI-Therapist and SRS in patients with LBP and their physical therapists, respectively. METHODS: One hundred patients with LBP and 18 physical therapists were recruited from physical therapy clinics in Brazil. Therapeutic alliance measures were collected at the initial assessment, prior to the second session, and at 2-month follow-up. The measurement properties investigated were reproducibility, internal consistency, ceiling/floor effects and responsiveness. RESULTS: Although WAI-Patient, WAI-Therapist and SRS were considered to have acceptable test-retest reliability (ICC2,1 > 0.70), these questionnaires showed problems with other measurement properties. WAI-Patient showed problems with internal consistency (i.e. Cronbach's alpha < 0.70 for all subscales). Presence of ceiling effect (i.e. > 15% of participants with the maximum score) and poor internal responsiveness were found for the WAI-Patient (Effect size = 0.15; 84% CI: 0.04 to 0.29) and for the SRS (Effect size = 0.05; 84% CI: -0.22 to 0.11). The WAI-Therapist revealed slightly better measurement properties. CONCLUSION: We identified psychometric limitations with most measurement properties of the WAI questionnaires and SRS. Future studies are needed to refine these tools.

Measurement Properties of the Brazilian-Portuguese Version of the Lumbar Spine Instability Questionnaire.

STUDY DESIGN: Cross-cultural adaptation and analysis of measurement properties. OBJECTIVE: To translate and cross-culturally adapt the Lumbar Spine Instability Questionnaire (LSIQ) into Brazilian-Portuguese and to test its measurement properties in Brazilian patients with low back pain. SUMMARY OF BACKGROUND DATA: The selection of subgroup of patients that respond better to specific interventions is the top research priority in the field of back pain. The LSIQ is a tool able to stratify patients with low back pain who responds better to motor control exercises. There is no Brazilian-Portuguese version of the LSIQ available. METHODS: The original version of the LSIQ was translated and cross-culturally adapted. We collected data from 100 patients with low back pain. In addition to LSIQ, we also collected information about physical activity levels (measured by the International Physical Activity Questionnaire short version), disability (measured by the Roland Morris Disability Questionnaire), pain intensity (measured by the Pain numerical Rating Scale), kinesiophobia (measured by the Tampa Scale of Kinesiophobia), and depression (measured by the Beck Depression Inventory). The measurement properties tested were internal consistency, reproducibility (reliability and agreement), construct validity, and ceiling and floor effects. RESULTS: The Brazilian-Portuguese version of the LSIQ showed good measurement properties with a Cronbach alpha of 0.79, an intraclass correlation coefficient of 0.75, a standard error of measurement of 1.65 points, and a minimal detectable change of 3.54 points. We did not detect ceiling and floor effects. The construct validity analysis was observed a moderate correlation between the LSIQ and Pain Numerical Rating Scale r = 0.46, Roland Morris Disability Questionnaire r = 0.66, Tampa Scale of Kinesiophobia r = 0.49, and Beck Depression Inventory r = 0.44. CONCLUSION: The Brazilian-Portuguese version of LIQ has adequate measurement properties and can be used in clinical practice and research. LEVEL OF EVIDENCE: NA.

Associação entre recrutamento de músculos abdominais com desfechos clínicos e risco prognóstico em indivíduos com dor lombar crônica não específica: estudo preliminar / Asociación entre el reclutamiento de músculos abdominales con resultados clínicos y riesgo pronóstico en sujetos con dolor lumbar crónico inespecífico: estudio preliminar / Association between abdominal muscles recruitment with clinical outcomes and prognostic risk in patients with chronic non-specific low back pain: a preliminary study

RESUMO Este estudo investigou a associação entre testes clínicos, desfechos clínicos e risco prognóstico de pacientes com dor lombar crônica não específica. Para esta pesquisa, 20 pacientes, maiores de 18 anos, foram selecionados por conveniência e submetidos à avaliação dos desfechos clínicos por meio de Escala numérica de dor e Questionário de incapacidade. Para classificação de risco prognóstico utilizou-se o questionário STarT Back, e para avaliar o recrutamento do músculo transverso do abdome foram utilizados os seguintes testes clínicos: Escala de classificação clínica (ECC); e medida da espessura dos músculos do abdome por meio de imagens ultrassonográficas (MEM-US). Os testes foram realizados em um único dia por avaliador treinado, e a ordem dos testes foi aleatória. Os coeficientes de correlação de Pearson (r) e Spearman (rS) foram utilizados para investigar a associação. Os resultados mostraram que as associações entre o risco prognóstico de dor lombar com os desfechos clínicos, dor e incapacidade foram moderadas (r=0,68 e r=0,57, respectivamente). Para ECC, as associações com incapacidade e risco prognóstico foram consideradas razoáveis (r=-0,34 e r=-0,36, respectivamente). Não houve associações com a MEM-US. Na amostra de baixo risco prognóstico, a relação do ECC com a incapacidade foi considerada moderada para boa, enquanto para dor a correlação foi razoável (rS=-0,62 e rS=-0,24, respectivamente). Concluímos que existe associação entre ECC com desfechos clínicos e risco prognóstico, e a estratificação, segundo o risco prognóstico, aumenta a relação observada. Futuros estudos devem ser conduzidos com novas medidas para avaliação do recrutamento muscular abdominal com amostras maiores.

RESUMEN En este estudio se examinó la asociación entre las pruebas clínicas, los resultados clínicos y el riesgo pronóstico en sujetos con dolor crónico inespecífico. Para la investigación, se eligieron 20 sujetos, mayores de 18 años, por conveniencia, y se les sometieron a evaluación de resultados clínicos a través de la Escala numérica de dolor y del Cuestionario de incapacidad. Para clasificar el riesgo pronóstico, se empleó el cuestionario STarT Back, y para evaluar el reclutamiento del músculo transverso del abdomen se emplearon las siguientes pruebas clínicas: la Escala de clasificación clínica (ECC); y la medición de la espesura de los músculos del abdomen a través de imágenes ecográficas (MEM-ES). Las pruebas fueron aplicadas en un solo día por un evaluador entrenado, y el orden de las pruebas fue aleatorio. Se emplearon los coeficientes de correlación de Pearson (r) y Spearman (rS) para investigar la asociación. Los resultados mostraron que fueron moderadas las asociaciones entre el riesgo pronóstico de dolor lumbar con los resultados clínicos, dolor e incapacidad (r=0,68 y r=0,57, respectivamente). Para la ECC, se consideraron razonables las asociaciones entre incapacidad y riesgo pronóstico (r=-0,34 y r=-0,36, respectivamente). Con la MEM-ES no hubo asociaciones. En el muestreo de bajo riesgo pronóstico, la relación de la ECC con la incapacidad fue considerada de moderada a buena, mientras que fue razonable la correlación para dolor (rS=-0,62 y rS=-0,24, respectivamente). Se concluyó que hay asociación entre la ECC y los resultados clínicos y riesgo pronóstico, y la estratificación, según el riesgo pronóstico, aumenta la relación observada. Deben llevarse a cabo nuevas investigaciones con nuevas mediciones para evaluar el reclutamiento del músculo abdominal con muestras mayores.

ABSTRACT This study investigated the association between clinical trials, clinical outcomes and prognosis risk of patients with chronic non-specific low back pain. Methodology: Twenty patients, older than 18 years, were selected by convenience and submitted to evaluation of clinical outcomes through a numeric pain rating scale and a disability questionnaire. To classify prognostic risk, we used the STarT Back questionnaire, and to evaluate transverse abdominal muscle recruitment, we used the following clinical tests: clinical rating scale (CRS); and measure of the thickness of the abdominal muscles using ultrasonography images (MEM-US). The tests were performed in a single day by a trained evaluator in random order. Pearson (r) and Spearman (rs) correlations were used to investigate the association. Results: The associations between the prognostic risk of low back pain with clinical outcomes, pain and disability, were moderate (r=0.68 and r=0.57, respectively). For CRS, associations with disability and prognosis risk were considered reasonable (r=-0.34 and r=-0.36, respectively). There were no associations with the MEM-US. In the low prognostic risk sample, the CRS's relationship with disability was considered from moderate to good, while pain correction was reasonable (rs=-0.62; and rs=-0.24, respectively). Conclusion: We observed an association between CRS and clinical outcomes and prognostic risk, with stratification, according to prognostic risk, that increases the relationship observed. Future studies should be conducted with new measures for the evaluation of abdominal muscle recruitment with larger samples.

Electromyographic analysis of the vertebral extensor muscles during the Biering-Sorensen Test / Análise eletromiográfica dos músculos extensores vertebrais durante o teste Biering-Sorensen / Análisis electromiográfico de los músculos extensores vertebrales durante la prueba Biering-Sorensen

The purpose of the study was to analyze the electromyographic signal of the multifidus, longissimus thoracis and the lumbar iliocostalis muscles during the Biering-Sorensen test in subjects without lower back pain. Twenty volunteers performed the test on three separate occasions. An analysis of variance detected a difference between the three test times (p = 0.0026). For the frequency domain, it was observed that there were differences between the multifidus and the lumbar erectors muscles; longissimus and iliocostalis muscles. However, in the time domain analysis, no difference was observed. As the values of the slope coefficients of median frequencies were higher for the multifidus muscle, compared to the longissimus and lumbar iliocostalis muscles, this may indicate a higher tendency toward muscle fatigue. Therefore, considering the applied methodology, the study of electromyographic signals in the frequency domain should be considered as an instrument to assess fatigue of the spinal extensor muscles in clinical situations.

O propósito deste estudo foi analisar o sinal eletromiográfico dos músculos multífido, longuíssimo torácico e iliocostal lombar durante o teste de Biering-Sorensen em sujeitos sem dor lombar. Vinte voluntários realizaram o teste em três momentos distintos. A análise da variância detectou diferença entre os três momentos do teste (p = 0,0026). Para o domínio da frequência, foi observada a presença de diferença entre o músculo multífido e os eretores lombares; longuíssimo e o iliocostal. Entretanto, na análise no domínio do tempo não foram observadas diferenças. Como o valor do coeficiente de inclinação da frequência mediana foi maior para o músculo multífido comparado aos músculos longuíssimo e iliocostal, isto pode indicar uma maior tendência deste músculo à fadiga. Portanto, considerando-se a metodologia aplicada, o estudo do sinal eletromiográfico no domínio da frequência deve ser considerado como um instrumento para avaliar a fadiga do músculos extensores da coluna vertebral em situações clínicas.

El propósito de este estudio fue analizar la señal eletromiográfica de los músculos multífido, longuíssimo torácica y iliocostal lumbar durante la prueba Biering-Sorensen en sujetos sin dolor lumbar. Veinte voluntarios realiza la prueba en tres momentos diferentes. El análisis de varianza detectó una diferencia entre las tres etapas de la prueba (p = 0,0026). Para el dominio de la frecuencia, se observó la presencia de la diferencia entre el multífido y erector lumbar; longuíssimo y iliocosta. Sin embargo, el análisis en el dominio del tiempo, no se observaron diferencias. Como el valor del coeficiente de la pendiente de la frecuencia media fue más alta para el músculo multífido en comparación con longuíssimo y iliocostal, esto puede indicar un aumento de la tendencia del músculo a la fatiga. Por lo tanto, teniendo en cuenta la metodología, el estudio de la señal electromiográfica en el dominio de la frecuencia debe ser considerado como un instrumento para evaluar la fatiga de los músculos extensores de la columna vertebral en entornos clínicos.