Psychological Features and Their Relationship to Movement-Based Subgroups in People Living With Low Back Pain

Quantifying lumbar mobility using a single tri-axial accelerometer

Background

Lumbar mobility is regarded as important for assessing and managing low back pain (LBP). Inertial Measurement Units (IMUs) are currently the most feasible technology for quantifying lumbar mobility in clinical and research settings. However, their gyroscopes are susceptible to drift errors, limiting their use for long-term remote monitoring.

Research question

Can a single tri-axial accelerometer provide an accurate and feasible alternative to a multi-sensor IMU for quantifying lumbar flexion mobility and velocity?

Methods

In this cross-sectional study, 18 healthy adults performed nine repetitions of full spinal flexion movements. Lumbar flexion mobility and velocity were quantified using a multi-sensor IMU and just the tri-axial accelerometer within the IMU. Correlations between the two methods were assessed for each percentile of the lumbar flexion movement cycle, and differences in measurements were modelled using a Generalised Additive Model (GAM).

Results

Very high correlations (r > 0.90) in flexion angles and velocities were found between the two methods for most of the movement cycle. However, the accelerometer overestimated lumbar flexion angle at the start (-4.7° [95 % CI -7.6° to -1.8°]) and end (-4.8° [95 % CI -7.7° to -1.9°]) of movement cycles, but underestimated angles (maximal difference of 4.3° [95 % CI 1.4° to 7.2°]) between 7 % and 92 % of the movement cycle. For flexion velocity, the accelerometer underestimated at the start (16.6°/s [95%CI 16.0 to 17.2°/s]) and overestimated (-12.3°/s [95%CI -12.9 to -11.7°/s]) at the end of the movement, compared to the IMU.

Significance

Despite the observed differences, the study suggests that a single tri-axial accelerometer could be a feasible tool for continuous remote monitoring of lumbar mobility and velocity. This finding has potential implications for the management of LBP, enabling more accessible and cost-effective monitoring of lumbar mobility in both clinical and research settings.

Quantifying lumbar sagittal plane kinematics using a wrist-worn inertial measurement unit

Wearable sensors like inertial measurement units (IMUs), and those available as smartphone or smartwatch applications, are increasingly used to quantify lumbar mobility. Currently, wearable sensors have to be placed on the back to measure lumbar mobility, meaning it cannot be used in unsupervised environments. This study aims to compare lumbar sagittal plane angles quantified from a wrist-worn against that of a lumbar-worn sensor. Twenty healthy participants were recruited. An IMU was placed on the right wrist and the L3 spinal level. Participants had to position their right forearm on their abdomen, parallel to the floor. Three sets of three consecutive repetitions of flexion, and extension were formed. Linear mixed models were performed to quantify the effect of region (lumbar vs. wrist) on six outcomes [minimum, maximum, range of motion (ROM) of flexion and extension]. Only flexion ROM was significantly different between the wrist and lumbar sensors, with a mean of 4.54° (95% CI = 1.82°-7.27°). Across all outcomes, the maximal difference between a wrist-worn and lumbar-worn sensor was <8°. A wrist-worn IMU sensor could be used to measure gross lumbar sagittal plane mobility in place of a lumbar-worn IMU. This may be useful for remote monitoring during rehabilitation.

Identifying Clinical Phenotypes in People Who Are Hispanic/Latino With Chronic Low Back Pain: Use of Sensor-Based Measures of Posture and Movement, Pain, and Psychological Factors

OBJECTIVE

The aim of this study was to identify clinical phenotypes using sensor-based measures of posture and movement, pain behavior, and psychological factors in Hispanic/Latino people with chronic low back pain (CLBP).

METHODS

Baseline measures from an ongoing clinical trial were analyzed for 81 Hispanic/Latino people with CLBP. Low back posture and movement were measured using commercial sensors during in-person testing and 8 hours of ecological monitoring. Magnitude, frequency, and duration of lumbar movements, sitting and standing postures were measured. Movement-evoked pain was assessed during in-person movement testing. Psychological measures included the Pain Catastrophizing Scale and the Fear Avoidance Beliefs Questionnaire. Random forest analysis was conducted to generate 2 groups and identify important variables that distinguish groups. Group differences in demographics, pain, psychological, and posture and movement variables were examined using t-tests and chi-square analyses.

RESULTS

Two subgroups of Hispanic/Latino people with CLBP were identified with minimal error (7.4% misclassification ["out-of-bag" error]). Ecological posture and movement measures best distinguished groups, although most movement-evoked pain and psychological measures did not. Group 1 had greater height and weight, lower movement frequency, more time in sitting, and less time in standing. Group 2 had a greater proportion of women than men, longer low back pain duration, higher movement frequency, more time in standing, and less time in sitting.

CONCLUSION

Two distinct clinical phenotypes of Hispanic/Latino people with CLBP were identified. One group was distinguished by greater height and weight and more sedentary posture and movement behavior; the second group had more women, longer duration of low back pain, higher lumbar spine movement frequency, and longer duration of standing postures.

IMPACT

Ecological measures of posture and movement are important for identifying 2 clinical phenotypes in Hispanic/Latino people with CLBP and may provide a basis for a more personalized plan of care.

LAY SUMMARY

Wearable sensors were used to measure low back posture and movement in Hispanic/Latino people with chronic low back pain. These posture and movement measures helped to identify 2 different clinical subgroups that will give physical therapists more information to better personalize treatment for chronic low back pain in Hispanic/Latino patients.

Association Between Smoking and Pain, Functional Disability, Anxiety and Depression in Patients With Chronic Low Back Pain

Objectives: Chronic low back pain (CLBP) accounts for a majority of the disability associated with LBP, which can produce long-term negative effects. This cross-sectional study aimed to investigate the association between smoking and pain, dysfunction and psychological status in patients with CLBP. Methods: The 54 patients with CLBP were recruited and divided into smoking and non-smoking groups. Their pain, dysfunction, anxiety, depression, fear and quality of life were evaluated. The amount of cigarettes smoked daily was recorded. Results: Significant differences in VAS, ODI, RMDQ and FABQ and the impact of LBP on life and work were found between smoking and non-smoking patients. In addition, a correlation was found between the daily cigarette smoking amount and VAS_max, FABQ_total, SDS and FABQ-W. Moreover, a correlation was observed between the amount of cigarettes smoked daily and the degree of impact of low back pain on work. Conclusion: The study found that smoking affected the aggravation of symptoms in patients with CLBP, which indicated that patients with CLBP and people at risk of LBP should be aware of the harm caused by smoking.

Road traffic delays in commuting workplace and musculoskeletal health among sedentary workers: A cross-sectional study in Dhaka city

OBJECTIVES

Despite previous research aimed at identifying factors linked to musculoskeletal health issues, there was no evidence about the relationship between road traffic delays (RTDs) and musculoskeletal health in sedentary employees. As a result, the aim of our research was to understand such a correlation among bank employees in Dhaka, Bangladesh.

METHODS

A cross-sectional analysis was conducted with bank employees who worked in sedentary settings. The Eriksen subjective health complaints scale was used to measure the eight items of musculoskeletal health complaints (MHCs), and RTDs were measured using principal component analysis using variables commute time, distance, and traffic congestion experience to work. The association between RTDs and MHCs was identified using a multilevel model after adjusting potential confounders.

RESULTS

A total of 628 employees (mean[SD] age, 36.1[7.0] years; 254[40.5%] women) participated in the study. Among the employees, the one-month prevalence of MHCs was 57.2%. The highest prevalence of MHCs was low-back pain (36.6%), followed by neck pain (22.9%) and upper-back pain (21.2%). Also, 136(21.7%) employees reported long-RTDs in commuting workplace and 81% of them had MHCs. The multilevel analysis identified that long-RTDs had a significant relationship with MHCs (adjusted odds ratio, AOR = 10.20, 95%CI = 5.41-16.91). Private transportation commuters reported 70% reduced odds of MHCs (AOR = 0.30, 95%CI = 0.15-0.59) and walking or bicycling commuters had 84% fewer MHCs (AOR = 0.16, 95%CI = 0.10-0.28) compared to public bus commuters.

CONCLUSIONS

Sedentary employees with long-RTDs reported increased MHCs, emphasizing the importance of including musculoskeletal exercise in office facilities. Findings of this study also highlight the need for a sound public transportation system in Dhaka city.

Effectiveness of Manual and Electrical Acupuncture for Chronic Non-specific Low Back Pain: A Randomized Controlled Trial

BACKGROUND

Low back pain is a common condition that can be effectively treated by acupuncture. However, several treatment point prescriptions and further electrical needle stimulation (i.e., local acupoints, distal acupoints, and sensitized acupoints) may be used. There is an implicit yet unexplored assumption about the evidence on manual and electrical stimulation techniques.

OBJECTIVE

The present study aims to identify effectiveness of electroacupuncture (EA) and manual acupuncture (MA) on pain and disability in patients with chronic nonspecific low back.

METHODS

This study is a randomized controlled clinical trial. Sixty-six patients between 20 and 60 years of age with non-specific chronic low back pain experiencing low back pain lasting for at least the previous three months and ≥3 points on a 10 numerical analogic scale. Patients diagnosed with chronic LBP were assigned to receive either 12 sessions of MA or EA. The primary outcomes measurements were pain intensity on Numeric Rating Scale and disability by Roland Morris Disability Questionnaire.

RESULTS

The participants reported improvements post-treatment to pain intensity and disability respectively; however, no differences between groups were observed. Regarding the secondary outcomes, we observed a between-group difference only for kinesiophobia in favor of the manual acupuncture group (difference = -4.1 points, 95% CI = -7.0 to -1.1). The results were maintained after 3 months of follow-up.

CONCLUSION

The study provides evidence that EA is not superior to MA treatment. Both therapies had similar efficacy in reducing pain and disability for chronic nonspecific low back pain.

Stress and Self-Efficacy as Long-Term Predictors for Chronic Low Back Pain: A Prospective Longitudinal Study

Purpose

Psychosocial variables are known risk factors for the development and chronification of low back pain (LBP). Psychosocial stress is one of these risk factors. Therefore, this study aims to identify the most important types of stress predicting LBP. Self-efficacy was included as a potential protective factor related to both, stress and pain.

Participants and Methods

This prospective observational study assessed n = 1071 subjects with low back pain over 2 years. Psychosocial stress was evaluated in a broad manner using instruments assessing perceived stress, stress experiences in work and social contexts, vital exhaustion and life-event stress. Further, self-efficacy and pain (characteristic pain intensity and disability) were assessed. Using least absolute shrinkage selection operator regression, important predictors of characteristic pain intensity and pain-related disability at 1-year and 2-years follow-up were analyzed.

Results

The final sample for the statistic procedure consisted of 588 subjects (age: 39.2 (±13.4) years; baseline pain intensity: 27.8 (±18.4); disability: 14.3 (±17.9)). In the 1-year follow-up, the stress types “tendency to worry”, “social isolation”, “work discontent” as well as vital exhaustion and negative life events were identified as risk factors for both pain intensity and pain-related disability. Within the 2-years follow-up, Lasso models identified the stress types “tendency to worry”, “social isolation”, “social conflicts”, and “perceived long-term stress” as potential risk factors for both pain intensity and disability. Furthermore, “self-efficacy” (“internality”, “self-concept”) and “social externality” play a role in reducing pain-related disability.

Conclusion

Stress experiences in social and work-related contexts were identified as important risk factors for LBP 1 or 2 years in the future, even in subjects with low initial pain levels. Self-efficacy turned out to be a protective factor for pain development, especially in the long-term follow-up. Results suggest a differentiation of stress types in addressing psychosocial factors in research, prevention and therapy approaches.

Hybrid Approach to Treatment Tailoring for Low Back Pain: A Proposed Model of Care

Various approaches have been used to guide the treatment of low back pain. These approaches have been considered in isolation and often tested against each other. An alternative view is that a model of care that involves a hybrid approach may benefit patients with low back pain. This commentary considers the potential benefits of a sequentially applied hybrid approach for treatment tailoring to optimize resource allocation to those most likely to require comprehensive care, and then decision making toward treatment paths with the greatest potential for success. In a first step, a prognosis-based approach, such as the Subgroups for Targeted Treatment Back Screening Tool (STarT Back), identifies individuals likely to require greater resource allocation. Although a clear path is indicated toward simple and psychologically informed care for the low- and high-risk groups, respectively, there is limited guidance for the large medium-risk group. For that group, the hybrid model provides a stepwise path of additional methods to guide treatment selection. This includes subgrouping based on pain mechanism to guide priority domains for the next phase, which includes tailoring of psychological and movement-based approaches. Motor control approaches to exercise would be indicated for individuals with medium risk and a nociceptive pain mechanism, with treatment guided by detailed assessment via one of several paradigms. Psychologically informed treatments are tailored to those with medium risk and a predominantly central pain mechanism, guided by detailed assessment of psychosocial features. A hybrid approach to a model of care could simplify treatment selection and take advantage of the benefits of each method in a time- and cost-efficient manner. J Orthop Sports Phys Ther 2019;49(6):453-463. Epub 13 Feb 2019. doi:10.2519/jospt.2019.8774.

Lumbar range of motion in chronic low back pain is predicted by task-specific, but not by general measures of pain-related fear

BACKGROUND

Most studies fail to show an association between higher levels of pain-related fear and protective movement behaviour in patients with chronic low back pain (CLBP). This may be explained by the fact that only general measures of pain-related fear have been used to examine the association with movement patterns. This study explored whether task-specific, instead of general measures of pain-related fear can predict movement behaviour.

METHODS

Fifty-five patients with CLBP and 54 healthy persons performed a lifting task while kinematic measurements were obtained to assess lumbar range of motion (ROM). Scores on the Photograph Daily Activities Series-Short Electronic Version (PHODA-SeV), Tampa Scale for Kinesiophobia and its Activity Avoidance and Somatic Focus subscales were used as general measures of pain-related fear. The score on a picture of the PHODA-SeV, showing a person lifting a heavy object with a bent back, was used as task-specific measure of pain-related fear.

RESULTS

Lumbar ROM was predicted by task-specific, but not by general measures of pain-related fear. Only the scores on one other picture of the PHODA-SeV, similar to the task-specific picture regarding threat value and movement characteristics, predicted the lumbar ROM. Compared to healthy persons, patients with CLBP used significantly less ROM, except the subgroup with a low score on the task-specific measure of pain-related fear, who used a similar ROM.

CONCLUSIONS

Our results suggest to use task-specific measures of pain-related fear when assessing the relationship with movement. It would be of interest to investigate whether reducing task-specific fear changes protective movement behaviour.

SIGNIFICANCE

This study shows that lumbar range of motion in CLBP is predicted by task-specific, but not by general measures of pain-related fear. This suggests that both in clinical practice and for research purposes, it might be recommended to use task-specific measures of pain-related fear when assessing the relationship with movement behaviour. This may help to disentangle the complex interactions between pain-related fear, movement and disability in patients with CLBP.