Correlation between lumbar dysfunction and fat infiltration in lumbar multifidus muscles in patients with low back pain

Background: Lumbar multifidus muscles (LMM) are important for spinal motion and stability. Low back pain (LBP) is often associated with fat infiltration in LMM. An increasing fat infiltration of LMM may lead to lumbar dysfunction. The purpose of this study was to investigate whether there is a correlation between the severity of lumbar dysfunction and the severity of fat infiltration of LMM. Methods: In a cross-sectional study, 42 patients with acute or chronic LBP were recruited. Their MRI findings were visually rated and graded using three criteria for fat accumulation in LMM: Grade 0 (0–10%), Grade 1 (10–50%) and Grade 2 (>50%). Lumbar sagittal range of motion, dynamic upright and seated posture control, sagittal movement control, body awareness and self-assessed functional disability were measured to determine the patients’ low back dysfunction. Results: The main result of this study was that increased severity of fat infiltration in the lumbar multifidus muscles correlated significantly with decreased range of motion of lumbar flexion (p = 0.032). No significant correlation was found between the severity of fat infiltration in LMM and impaired movement control, posture control, body awareness or self-assessed functional disability. Conclusion: This is the first study investigating the relationship between the severity of fat infiltration in LMM and the severity of lumbar dysfunction. The results of this study will contribute to the understanding of the mechanisms leading to fat infiltration of LMM and its relation to spinal function. Further studies should investigate whether specific treatment strategies are effective in reducing or preventing fat infiltration of LMM

Cervical musculoskeletal impairments and pressure pain sensitivity in office workers with headache

Background: Office workers are specifically vulnerable to headache conditions. Neck pain is reported by almost 80% of patients with headaches. Associations between currently recommended tests to examine cervical musculoskeletal impairments, pressure pain sensitivity and self-reported variables in headache, are unknown. The aim of this study is to evaluate whether cervical musculoskeletal impairments and pressure pain sensitivity are associated with self-reported headache variables in office workers. Methods: This study reports a cross-sectional analysis using baseline data of a randomized controlled trial. Office workers with headache were included in this analysis. Multivariate associations, controlled for age, sex and neck pain, between cervical musculoskeletal variables (strength, endurance, range of motion, movement control) and pressure pain threshold (PPT) over the neck and self-reported headache variables, such as frequency, intensity, and the Headache-Impact-Test-6, were examined. Results: Eighty-eight office workers with a 4-week headache frequency of 4.8 (±5.1) days, a moderate average headache intensity (4.5 ± 2.1 on the NRS), and “some impact” (mean score: 53.7 ± 7.9) on the headache-impact-test-6, were included. Range of motion and PPT tested over the upper cervical spine were found to be most consistently associated with any headache variable. An adjusted R2 of 0.26 was found to explain headache intensity and the score on the Headache-Impact-Test-6 by several cervical musculoskeletal and PPT variables. Discussion: Cervical musculoskeletal impairments can explain, irrespective of coexisting neck pain, only little variability of the presence of headache in office workers. Neck pain is likely a symptom of the headache condition, and not a separate entity

A Multi-component Intervention (NEXpro) Reduces Neck Pain-Related Work Productivity Loss: A Randomized Controlled Trial Among Swiss Office Workers.

Purpose Neck pain is common among office workers and leads to work productivity loss. This study aimed to investigate the effect of a multi-component intervention on neck pain-related work productivity loss among Swiss office workers. Methods Office workers, aged 18-65 years, and without serious neck-related health problems were recruited from two organisations for our stepped-wedge cluster randomized controlled trial. The 12-week multi-component intervention included neck exercises, health-promotion information, and workplace ergonomics. The primary outcome of neck pain-related work productivity loss was measured using the Work Productivity and Activity Impairment Questionnaire and expressed as percentages of working time. In addition, we reported the weekly monetary value of neck pain-related work productivity loss. Data was analysed on an intention-to-treat basis using a generalized linear mixed-effects model. Results Data from 120 participants were analysed with 517 observations. At baseline, the mean age was 43.7 years (SD 9.8 years), 71.7% of participants were female (N = 86), about 80% (N = 95) reported mild to moderate neck pain, and neck pain-related work productivity loss was 12% of working time (absenteeism: 1.2%, presenteeism: 10.8%). We found an effect of our multi-component intervention on neck pain-related work productivity loss, with a marginal predicted mean reduction of 2.8 percentage points (b = -0.27; 95% CI: -0.54 to -0.001, p = 0.049). Weekly saved costs were Swiss Francs 27.40 per participant. Conclusions: Our study provides evidence for the effectiveness of a multi-component intervention to reduce neck pain-related work productivity loss with implications for employers, employees, and policy makers.Trial Registration ClinicalTrials.gov, NCT04169646. Registered 15 November 2019-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04169646

A Multi-component Intervention (NEXpro) Reduces Neck Pain-Related Work Productivity Loss: A Randomized Controlled Trial Among Swiss Office Workers

Purpose Neck pain is common among office workers and leads to work productivity loss. This study aimed to investigate the effect of a multi-component intervention on neck pain-related work productivity loss among Swiss office workers. Methods Office workers, aged 18-65 years, and without serious neck-related health problems were recruited from two organisations for our stepped-wedge cluster randomized controlled trial. The 12-week multi-component intervention included neck exercises, health-promotion information, and workplace ergonomics. The primary outcome of neck pain-related work productivity loss was measured using the Work Productivity and Activity Impairment Questionnaire and expressed as percentages of working time. In addition, we reported the weekly monetary value of neck pain-related work productivity loss. Data was analysed on an intention-to-treat basis using a generalized linear mixed-effects model. Results Data from 120 participants were analysed with 517 observations. At baseline, the mean age was 43.7 years (SD 9.8 years), 71.7% of participants were female (N = 86), about 80% (N = 95) reported mild to moderate neck pain, and neck pain-related work productivity loss was 12% of working time (absenteeism: 1.2%, presenteeism: 10.8%). We found an effect of our multi-component intervention on neck pain-related work productivity loss, with a marginal predicted mean reduction of 2.8 percentage points (b = -0.27; 95% CI: -0.54 to -0.001, p = 0.049). Weekly saved costs were Swiss Francs 27.40 per participant. Conclusions: Our study provides evidence for the effectiveness of a multi-component intervention to reduce neck pain-related work productivity loss with implications for employers, employees, and policy makers.Trial Registration ClinicalTrials.gov, NCT04169646. Registered 15 November 2019-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04169646 . Keywords: Absenteeism; Ergonomics; Exercise; Health promotion; Presenteeis

Association of exercise frequency and type with neck pain intensity : a quantitative analysis in office workers

Background: The guideline for the treatment of neck pain recommends active therapy, such as exercise. The aim of this study was to investigate the association of exercise frequency and type with neck pain intensity in a sample of office workers. Methods: This longitudinal analysis is among a subset of our randomized controlled trial “Neck exercise for productivity” (NEXpro). Office workers from two Swiss organisations without severe neck problems were included. All office workers were asked to perform a 12-week exercise program in spring 2020 to reduce their neck pain. Exercise frequency was quantified by the number of exercises performed. Exercise type corresponded to the number of strengthening and non-strengthening exercises performed. Both were measured by an application on participants’ digital devices. Neck pain intensity was assessed before and after the intervention using the Numeric Rating Scale NRS 0-10, and the difference was calculated. A linear regression model was fitted to the data to estimate the association of exercise frequency and type with reduction in neck pain intensity. Results: Forty office workers aged 27.3 to 63.7 years (mean 44.9) participated in the study, 75% of whom were women. The mean neck pain intensity was NRS 2.8/10 before and NRS 1.8/10 after the intervention. Over 12 weeks, an average of 225 exercises were performed, of which 145.1 were strengthening and 80.6 were non-strengthening exercises. No statistically significant association was found with neck pain intensity for either exercise frequency (b=0.002, 95% CI from -0.003 to 0.007, p=0.38) or exercise type (strengthening: b=0.001, 95% CI from -0.007 to 0.009, p=0.75; non strengthening: b=0.012, 95% CI from - 0.001 to 0.026, p=0.07). Conclusion: Our results do not indicate that participants who exercised more frequently and performed strengthening exercises experienced a greater reduction in neck pain intensity

Association of neck pain, neck disability, and fear avoidance beliefs with adherence to exercise : a quantitative analysis in office workers

Background: Adherence to exercise is a common problem in occupational health studies. The aim of this study was to investigate the association of pain-specific and psychological factors with adherence to exercises in a sample of office workers. Methods: This analysis is among a subset of our randomized controlled trial “Neck exercise for productivity” (NEXpro). Office workers from two Swiss organisations without severe neck problems were included (N=69). All office workers were asked to perform a 12-week neck exercise program in either spring or autumn 2020. The construct variable of adherence to exercise was defined as the number of days performing a set of exercises (minimum=0 days, maximum=84 days), and was measured by an application on participants’ digital devices. The predictors of neck disability (Neck Disability Index 0-100%), neck pain intensity (Numeric Rating Scale NRS 0-10), neck pain frequency (number of days with neck pain within the last 4-weeks), and fear avoidance beliefs (Fear Avoidance Beliefs Questionnaire 0-18) were collected before intervention commencement. A linear regression model was fitted to the data to predict adherence to exercise. Results: The majority of office workers were female (69.9%) and between 25.7 and 63.3 years of age (mean 44.9). Adherence to exercise was 33.2/84 days, with a mean neck disability of 12.1%, a mean neck pain intensity of NRS 2.6/10, a mean neck pain frequency of 7.6/28 days, and a mean fear avoidance beliefs value of 5/18. We found weak evidence for an association of neck disability with adherence to exercise (b=0.379, 95%CI from -0.039 to 0.797, p=0.075). Conclusion: Participants with higher neck disability tended to have higher adherence to exercise as measured by more days on which they performed exercises. Neck pain intensity, neck pain frequency, and fear avoidance beliefs were not found to be predictive of adherence to exercise

Nonspecific neck pain and physical factors of the neck : a quantitative analysis in office workers

Background: Nonspecific neck pain is a major burden in office workers. The aim of this study was to investigate the relationship of nonspecific neck pain and physical factors of the neck. Methods: This quantitative analysis is among a subset of our stepped-wedge cluster-randomized controlled trial “Neck exercise for productivity” (NEXpro). Office workers from two Swiss organisations without severe neck problems were included. All data were collected in January 2020. Neck pain was quantified with a measure of intensity (Numeric Rating Scale NRS 0-10), disability (Neck Disability Index NDI 0-100%), and frequency (number of days with neck pain in the last four weeks). Among physical factors of the neck, we assessed strength [Newton] and endurance [seconds] of neck flexors, as well as movement control of the neck [number of positive tests results out of seven]. Pearson correlation coefficients were calculated. Results: 95 office workers with a mean age of 43.9 years (SD 9.58) participated in the study, 74% of whom were women. Participants reported a mean neck pain intensity of NRS 2.99/10, a mean neck disability of 14.9%, and a mean neck pain frequency of 8.56/30 days. Mean strength of neck flexors was 48.7N, mean endurance of neck flexors was 58.3 seconds, and mean movement control of the neck was 4.9/7 positive tests. A moderate and negative statistically significant correlation was found between neck pain intensity and strength of the neck flexors (r = -0.36, p = 0.003). Conclusion: We have only been able to demonstrate a relationship between neck pain intensity and strength of neck flexors, but not for movement control of the neck, endurance of neck flexors, neck disability, or neck pain frequency. Further research is needed to draw causal inferences and investigate factors other than physical, e.g., psychological

No evidence for an effect of the first COVID-19 lockdown on neck pain and neck disability among Swiss office workers

Introduction: During March and April 2020, the COVID-19 pandemic forced around50 % of employees of Switzerland into a working from home setting. Working from home appears to have considerably changed the work experience of office workers. Newspapers reported an increase in non-specific neck pain as a negative consequence of working from home. Therefore, the main driver for this abstract was to confirm these observations with higher levels of evidence. Purpose of the study: The aim of this analysis was to investigate the effect of the first COVID-19 lockdown on neck pain. We hypothesised that the COVID-19 lockdown would increase neck pain. Methods: This longitudinal analysis is based on control group data from an ongoing stepped-wedge cluster randomised controlled trial. Office workers from two Swiss organisations, aged 18-65 years, were included. Baseline data collected in January 2020 before the COVID-19 pandemic were compared with follow-up data collected during the fourth and fifth week of the first lockdown in April 2020. Neck pain was assessed with a measure of intensity (numeric rating scale NRS from 0 = no pain to 10 = maximum pain), frequency (number of days within the last 28 days), and disability (neck disability index from 0 % = no disability to 100 % = maximum disability). Paired Wilcoxon signed rank tests were performed for statistical analysis as the normality assumption was not met. Results: Data from 76 participants were analysed. The mean age was 42.7 years (ranging from 21.8 to 62.7) at baseline and fifty-four participants (71.1 %) were female. At baseline, the meanintensity of neck pain was NRS 2.3 (± 1.9), mean frequency of neck pain 4.5 / 28 days (± 8.3), and mean neck disability 11.7 % (± 10.0). At follow-up, the mean intensity of neck pain was NRS 2.2 (± 2.2), mean frequency of neck pain 6.8 / 28 days (± 7.4), and mean neck disability 11.1 % (± 10.9). We found no evidence for a difference in the intensity of neck pain (estimate = 2.59*10-5, 95 % CI from -0.50 to 0.50, p-value = 0.607), frequency of neck pain (estimate = 3.26*10-5, 95 % CI from -2.00 to 2.50, p-value = 0.964), or neck disability index (estimate = 4.43*10-6, 95 % CI from -2.00 to 3.00, p-value = 0.794) between both measurement time points. Conclusion: The first COVID-19 lockdown did not result in a difference of neck pain among our sample of office workers, neither in intensity nor in frequency nor in disability. Therefore, our hypothesis and the findings of the newspapers could not be confirmed. A higher number of work breaks taken as well as improved working times and work-life balance may have contributed to this result. To enable more comprehensive statements, further dimensions of pain (i.e., duration) and the effect of psychosocial factors (i.e., mental health) would need to be investigated

Quantum-mechanical model of the Kerr-Newman black hole

We consider a Hamiltonian quantum theory of stationary spacetimes containing a Kerr-Newman black hole. The physical phase space of such spacetimes is just six-dimensional, and it is spanned by the mass $M$, the electric charge $Q$ and angular momentum $J$ of the hole, together with the corresponding canonical momenta. In this six-dimensional phase space we perform a canonical transformation such that the resulting configuration variables describe the dynamical properties of Kerr-Newman black holes in a natural manner. The classical Hamiltonian written in terms of these variables and their conjugate momenta is replaced by the corresponding self-adjoint Hamiltonian operator and an eigenvalue equation for the Arnowitt-Deser-Misner (ADM) mass of the hole, from the point of view of a distant observer at rest, is obtained. In a certain very restricted sense, this eigenvalue equation may be viewed as a sort of "Schr\"odinger equation of black holes". Our "Schr\"odinger equation" implies that the ADM mass, electric charge and angular momentum spectra of black holes are discrete, and the mass spectrum is bounded from below. Moreover, the spectrum of the quantity $M^2-Q^2-a^2$, where $a$ is the angular momentum per unit mass of the hole, is strictly positive when an appropriate self-adjoint extension is chosen. The WKB analysis yields the result that the large eigenvalues of $M$, $Q$ and $a$ are of the form $\sqrt{2n}$, where $n$ is an integer. It turns out that this result is closely related to Bekenstein's proposal on the discrete horizon area spectrum of black holes.Comment: 30 pages, 3 figures, RevTe