Identifying Subgroups of Patients With Chronic Nonspecific Low Back Pain Based on a Multifactorial Approach: Protocol For a Prospective Study

Relationship between the flexion relaxation phenomenon and kinematics of the multi-segmental spine in nonspecific chronic low back pain patients

The flexion relaxation phenomenon (FRP) is characterized by the reduction of paraspinal muscle activity at maximum trunk flexion. FRP is reported to be altered (persistence of spinal muscle activity) in more than half of nonspecific chronic low back pain (NSCLBP) patients. Little is known about how the multi-segmental spine affects FRP. The aim of this observational study was to investigate the relationship between FRP and kinematic parameters of the multi-segmental spine in NSCLBP patients. Forty NSCLBP patients and thirty-five asymptomatic participants performed a standing maximal trunk flexion task. Surface electromyography was recorded along the erector spinae longissimus. The kinematics of the spine were assessed using a 3D motion analysis system. The investigated spinal segments were upper thoracic, lower thoracic, thoracolumbar, upper lumbar, lower lumbar, and lumbopelvic. Upper lumbar ROM, anterior sagittal inclination of the upper lumbar relative to the lower lumbar in the upright position, and ROM of the upper lumbar relative to the lower lumbar during full trunk flexion were significantly correlated with the flexion relaxation ratio (Rho 0.42 to 0.58, p < 0.006). The relative position and movement of the upper lumbar segment seem to play an important role in the presence or absence of FRP in NSCLBP patients.

Effects of pilates exercises on radiographic lumbo-pelvic alignment and range of motion in non-specific low back pain patients

OBJECTIVES

To determine the effects of Pilates exercises on lumbo-pelvic alignment in non-specific low back pain (NSLBP) patients.

METHODS

Twenty-two patients (Male:7; Female:15) with NSLBP aged 20-65 years were recruited and classified based on a modified O'Sullivan's classification system into flexion pattern (FP) or active extension pattern (EP) groups. Oswestry Disability index (ODI), Roland-Morris Disability Questionnaire (RMDQ) as well as radiographic lumbar global range of motion (ROM) and lumbo-pelvic alignment were measured Pre- and immediately post-intervention and at 6- and 12-month. The intervention included supervised six-weeks Pilates program with 60 min per session and up to two sessions per week.

RESULTS

Lumbar lordosis, sacral slope and sacral inclination were found to be significantly different between the FP and EP groups based on the O'Sullivan's classification system. However, despite the significant changes in RMDQ (p = 0.001), no significant changes were found for any of the alignment parameters (p > 0.05) post intervention for both groups. For lumbar global ROM, a statistically significant change was observed for the EP group (p = 0.028) but not for the FP group (p = 0.249). No significant correlations were identified between any of the self-reported outcomes, radiographic alignment and ROM parameters.

CONCLUSIONS

Patients self-perceived long-term functional improvements based on responding to questionnaires after Pilates exercises were not reflected in significant changes in lumbo-pelvic alignment or lumbar ROM. This may be due to the current cohort demonstrating within normal ranges due to the lesser severity of their condition, but further research is needed for clarification.

Measuring objective physical activity in people with chronic low back pain using accelerometers: a scoping review

Purpose

Accelerometers can be used to objectively measure physical activity. They could be offered to people with chronic low back pain (CLBP) who are encouraged to maintain an active lifestyle. The aim of this study was to examine the use of accelerometers in studies of people with CLBP and to synthesize the main results regarding the measurement of objective physical activity.

Methods

A scoping review was conducted following Arksey and O'Malley's framework. Relevant studies were collected from 4 electronic databases (PubMed, Embase, CINHAL, Web of Science) between January 2000 and July 2023. Two reviewers independently screened all studies and extracted data.

Results

40 publications out of 810 citations were included for analysis. The use of accelerometers in people with CLBP differed across studies; the duration of measurement, physical activity outcomes and models varied, and several limitations of accelerometry were reported. The main results of objective physical activity measures varied and were sometimes contradictory. Thus, they question the validity of measurement methods and provide the opportunity to discuss the objective physical activity of people with CLBP.

Conclusions

Accelerometers have the potential to monitor physical performance in people with CLBP; however, important technical limitations must be overcome.

Measurement properties of 72 movement biomarkers aiming to discriminate non‑specific chronic low back pain patients from an asymptomatic population

The identification of relevant and valid biomarkers to distinguish patients with non-specific chronic low back pain (NSCLBP) from an asymptomatic population in terms of musculoskeletal factors could contribute to patient follow-up and to evaluate therapeutic strategies. Several parameters related to movement impairments have been proposed in the literature in that respect. However, most of them were assessed in only one study, and only 8% were evaluated in terms of reliability, validity and interpretability. The aim of this study was to consolidate the current knowledge about movement biomarkers to discriminate NSCLBP patients from an asymptomatic population. For that, an experimental protocol was established to assess the reliability, validity and interpretability of a set of 72 movement biomarkers on 30 asymptomatic participants and 30 NSCLBP patients. Correlations between the biomarkers and common patient reported outcome measures were also analysed. Four biomarkers reached at least a good level in reliability (ICC ≥ 0.75) and validity (significant difference between asymptomatic participants and NSCLBP patients, p ≤ 0.01) domains and could thus be possibly considered as valuable biomarkers: maximal lumbar sagittal angle, lumbar sagittal angle range of motion, mean lumbar sagittal angular velocity, and maximal upper lumbar sagittal angle during trunk sagittal bending. These four biomarkers demonstrated typically larger values in asymptomatic participants than in NSCLBP patients. They are in general weakly correlated with patient reported outcome measures, arguing for a potential interest in including related musculoskeletal factors in the establishment of a valuable diagnosis and in guiding treatment response.

Low back pain in patients hospitalised with liver cirrhosis- a retrospective study

BACKGROUND

Lower back pain is a common issue, but little is known about the prevalence of pain in patients with liver cirrhosis during hospitalisation. Therefore, the objective of this study was to determine lower back pain in patients with liver cirrhosis.

METHODS

The sample consisted of patients with liver cirrhosis (n = 79; men n = 55; women n = 24; mean age = 55.79 ± 12.52 years). The hospitalised patients were mobile. The presence and intensity of pain were assessed in the lumbar spine during hospitalisation. The presence of pain was assessed using the visual analogue pain scale (0-10). The range of motion of the lower spine was assessed using the Schober and Stibor tests. Frailty was measured by Liver Frailty Index (LFI). The condition of liver disease was evaluated using The Model For the End-Stage Liver Disease (MELD) and Child-Pugh score (CPS) and ascites classification. Student's t test and Mann-Whitney test were used for analysis of the difference of group. Analysis of variance (ANOVA) with the Tukey post hoc test was used to test differences between categories of liver frailty index. The Kruskal-Wallis test was used to test pain distribution. Statistical significance was determined at the α-0.05 significance level.

RESULT

The prevalence of pain in patients with liver cirrhosis was 13.92% (n = 11), and the mean intensity of pain according to the visual analogue scale was 3.73 (± 1.90). Lower back pain was present in patients with ascites (15.91%; n = 7) and without ascites (11.43%; n = 4). The prevalence of lower back pain was not statistically significant between patients with and without ascites (p = 0,426). The base of Schober's assessment mean score was 3.74 cm (± 1.81), and based on Stibor's assessment mean score was 5.84 cm (± 2.23).

CONCLUSION

Lower back pain in patients with liver cirrhosis is a problem that requires attention. Restricted spinal mobility has been reported in patients with back pain, according to Stibor, compared to patients without pain. There was no difference in the incidence of pain in patients with and without ascites.

Sensitivity and specificity of the flexion and extension relaxation ratios to identify altered paraspinal muscles' flexion relaxation phenomenon in nonspecific chronic low back pain patients

BACKGROUND

Among the main methods used to identify an altered flexion relaxation phenomenon (FRP) in nonspecific chronic low back pain (NSCLBP), it has been previously demonstrated that flexion relaxation ratio (FRR) and extension relaxation ratio (ERR) are more objective than the visual reference method.

OBJECTIVE

To determine the sensitivity and specificity of the different methods used to calculate the ratios in terms of their ability to identify an altered FRP in NSCLBP.

METHODS

Forty-four NSCLBP patients performed a standing maximal trunk flexion task. Surface electromyography (sEMG) was recorded along the erector spinae longissimus (ESL) and multifidus (MF) muscles. Altered FRP based on sEMG was visually identified by three experts (current standard). Six FRR methods and five ERR methods were used both for the ESL and MF muscles. ROC curves (with areas under the curve (AUC) and sensitivity/specificity) were generated for each ratio.

RESULTS

All methods used to calculate these ratios had an AUC higher than 0.9, excellent sensitivity (>90 %), and good specificity (80-100 %) for both ESL and MF muscles.

CONCLUSION

Both FRP ratios (FRR and ERR) for MF and ESL muscles, appear to be an objective, sensitive and specific method for identifying altered FRP in NSCLBP patients.

Hipervigilância postural e percepção da postura correta sentada em indivíduos com e sem dor lombar

Objetivos Verificar se há diferença na hipervigilância postural sentada em indivíduos com e sem dor lombar. Além disso, observar se há diferença na percepção da postura correta sentada entre indivíduos com dor lombar e sem dor lombar.

Métodos O presente estudo possui delineamento observacional transversal, como tamanho amostral de 92 indivíduos, posteriormente divididos igualmente em dois grupos (com dor lombar e sem dor lombar). Foram utilizados dois instrumentos: a escala de hipervigilância para analisar a frequência que voluntários corrigem a postura sentada no dia; e o quadro de posturas para investigar a percepção dos voluntários sobre a postura correta sentada. Os dados foram submetidos ao teste de Normalidade de Shapiro-Wilk. Para comparar os valores da Escala de Hipervigilância foi utilizado o teste de Mann-Whitney e o teste Qui-quadrado e exato de Fisher para avaliação da postura correta sentada.

Resultados Não houve diferença significativa entre a hipervigilância postural sentada entre indivíduos com dor lombar e sem dor lombar. Não houve diferença significativa entre a escolha da postura correta sentada entre o grupo de indivíduos com e sem dor lombar.

Conclusão Não há diferença entre a escolha da postura correta sentada e quantidade de hipervigilância postural em indivíduos com ou sem dor lombar.

Altered muscle strength and flexibility among a subgroup of women with chronic nonspecific low back pain: Cross-sectional case-control study

OBJECTIVE

To compare muscle strength and flexibility among a subgroup of women with extension-related chronic nonspecific low back pain (CNLBP) with healthy controls.

METHODS

In this case-control study, 32 subjects with and without extension-related CNLBP were tested (n = 16 in each group). Gluteal, abdominal, paravertebral, and hamstring strength, along with hip flexor flexibility and hamstring flexibility were compared between groups. Data were analyzed using the Mann-Whitney test (p < .007).

RESULTS

The CNLBP subgroup displayed significantly lower strength of all muscles analyzed (p < .007), with the exception of gluteus medius. The flexibility of the hip flexors and hamstrings were not significantly reduced among the women with CNLBP (p > .007).

DISCUSSION

The present study showed that alterations in muscle strength, but not flexibility, partly consistent with those previously hypothesized but not objectively reported, were present among a subgroup of women with extension-related CNLBP. These results may have implications for the selection of therapeutic exercises among this subgroup of people with CNLBP.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Cross-cultural adaptation and validity of the Spanish fear-avoidance components scale and clinical implications in primary care

BACKGROUND

Pain-related fear-avoidance (FA) is a common problem affecting many patients with painful medical conditions. As there is great interest in the clinical importance of the relationship between FA and disability, several questionnaires have been developed to measure FA. The Fear-Avoidance Components Scale (FACS) is a recently developed patient-reported instrument that addresses critical issues not previously considered in previous FA-related questionnaires. The original English version of the FACS demonstrated good reliability, internal consistency, and construct, criterion, and predictive validity. Two factors were determined: General Fear Avoidance and Types of Activities That are Avoided. The aim of this study was to to translate the FACS into European-style Spanish (FACS-Sp), and validate its psychometric properties.

METHODS

This two-stage psychometric study included 330 subjects with various chronic musculoskeletal pain disorders. An initial translation and cross-cultural adaptation of the FACS, from English to Spanish, was performed. Then, critical psychometric properties were analysed, including internal consistency by Cronbach's α coefficients, structural validity from the Maximum Likelihood Extraction (MLE), and convergent validity by Pearson correlation with the Central Sensitization Inventory (CSI).

RESULTS

This study reports for the first time the psychometric properties of the Spanish version of the FACS. Total scores ranged from 0 to 88 points, with a mean of 30.49 (±17.18). The FACS-Sp showed a high internal consistency for factor 1 (α = 0.902) and factor 2 (α = 0.88). Factor structure was two-dimensional and supported structural validity, accounting for 48.75% of the total variance. Convergent validity analysis found a significant Pearson correlation r = 0.414.

CONCLUSION

This study reports for the first time the psychometric properties of the Spanish version of the FACS-Sp. Psychometric properties supported the validation of FACS-Sp and ensured the conceptual equivalence with the original English version. In primary care and chronic pain rehabilitation, FA assessment is crucial for clinical decision-making and treatment guidance. The FACS-Sp offers a new measure of FA in Spanish speaking populations. Future research on the FACS-Sp should evaluate test-retest reliability, treatment responsiveness and psychometric comparisons with other translated versions.

Flexion-Relaxation Ratio Asymmetry and Its Relation With Trunk Lateral ROM in Individuals With and Without Chronic Nonspecific Low Back Pain

STUDY DESIGN

A cross-sectional comparative study.

OBJECTIVE

The present study aimed to investigate the relationship between the FR phenomenon asymmetry of lumbar muscles and trunk lateral range of motion (ROM) asymmetry in nonspecific chronic low back pain (NSCLBP) patients.

SUMMARY OF BACKGROUND DATA

Imbalance in trunk muscle activation between right and left sides can induce pain by loading the spine incorrectly, especially in patients with NSCLBP. A previous study reported a greater asymmetry in the FR phenomenon of the erector spinae in NSCLBP patients than in asymptomatic participants (APs). Imbalance of muscle properties, such as trunk ROM, has been suggested as a possible cause of this observed asymmetry.

METHODS

Twenty-eight NSCLBP patients and 22 AP performed 3 standing maximal trunk flexions. Surface electromyography was recorded bilaterally for erector spinae longissimus and lumbar multifidus. A FR ratio was calculated for each muscle. The fingertip-to-thigh test was performed to assess trunk lateral ROM. Each parameter's asymmetry was calculated as the absolute difference between right and left sides.

RESULTS

NSCLBP patients present a significantly lower trunk lateral ROM than AP. FR ratio asymmetry of the erector spinae was significantly greater in NSCLBP patients than in AP (P < 0.05). FR ratio asymmetry of the multifidus and trunk lateral ROM asymmetry were not significantly different between groups. Significant correlation (r = 0.49) between FR ratio asymmetry of erector spinae and trunk lateral ROM asymmetry was observed only for patients with NSCLBP.

CONCLUSION

The present findings showed that FR ratio asymmetry of erector spinae longissimus is moderately correlated with trunk lateral ROM asymmetry. In addition, the results confirmed that patients with NSCLBP present a reduced trunk lateral ROM, a FR ratio asymmetry of the erector spinae which is correlated with trunk rotation. These findings suggested an imbalance spine loading which can contribute to the persistence of pain.

LEVEL OF EVIDENCE

3.

Muscle Activity Pattern Dysfunction During Sit to Stand and Stand to Sit in the Movement System Impairment Subgroups of Low Back Pain

OBJECTIVE

To investigate impairment in the activity pattern of some muscles involved in sit to stand (STD) and stand to sit (STS) among 2 low back pain (LBP) subgroups of the Movement System Impairment (MSI) model.

DESIGN

Case-control study.

SETTING

A university medical center.

PARTICIPANTS

Fifteen women without chronic LBP and 22 women with chronic LBP (N=37) in 2 subgroups (15 into the lumbar extension rotation (LER) and 7 into lumbar flexion rotation [LFR]) voluntarily participated in this study.

INTERVENTIONS

Participants were asked to perform STD and STS at a preferred speed. Surface electromyography (EMG) were measured bilaterally from the internal oblique (IO), lumbar erector spine (ES), medial hamstring (MH), and lateral hamstring (LH) muscles.

MAIN OUTCOME MEASURES

Changes in mean and maximum amplitude, time to peak amplitude, duration of muscle activity, and bilateral asymmetry of these variables.

RESULTS

During STD, bilateral asymmetry in mean amplitude of MH in the LER subgroup (P=.031) and bilateral asymmetry in duration of LH in the LFR subgroup (P=.026) were exhibited. Also, in this task reduced time to peak left MH activation were found in the LFR subgroup than 2 other groups (control; P=.028/LER; P=.004). During STS, increased left ES maximum amplitude were observed in the LFR subgroup than LER subgroup (P=.029). Also, reduced time to peak right ES (P=.035) and left LH (P=.038) activation in the LER subgroup than control subjects and reduced time to peak left LH activation in LFR subgroup than control subjects (P=.041) were observed during STS.

CONCLUSIONS

The differences between the 2 LBP subgroups may be a result of impairment in the activity pattern of some muscles during functional activity.