Concurrent and discriminant validity of ActiGraph waist and wrist cut-points to measure sedentary behaviour, activity level, and posture in office work.

BACKGROUND: Sedentary Behaviour (SB) gets an increasing attention from ergonomics and public health due to its associated detrimental health effects. A large number of studies record SB with ActiGraph counts-per-minute cut-points, but we still lack valid information about what the cut-points tell us about office work. This study therefore analysed the concurrent and discriminant validity of commonly used cut-points to measure SB, activity level, and posture. METHODS: Thirty office workers completed four office tasks at three workplaces (conventional chair, activity-promoting chair, and standing desk) while wearing two ActiGraphs (waist and wrist). Indirect calorimetry and prescribed posture served as reference criteria. Generalized Estimation Equations analysed workplace and task effects on the activity level and counts-per-minute, and kappa statistics and ROC curves analysed the cut-point validity. RESULTS: The activity-promoting chair (p < 0.001, ES ≥ 0.66) but not the standing desk (p = 1.0) increased the activity level, and both these workplaces increased the waist (p ≤ 0.003, ES ≥ 0.63) but not the wrist counts-per-minute (p = 0.74) compared to the conventional chair. The concurrent and discriminant validity was higher for activity level (kappa: 0.52-0.56 and 0.38-0.45, respectively) than for SB and posture (kappa ≤0.35 and ≤ 0.19, respectively). Furthermore, the discriminant validity for activity level was higher for task effects (kappa: 0.42-0.48) than for workplace effects (0.13-0.24). CONCLUSIONS: ActiGraph counts-per-minute for waist and wrist placement were - independently of the chosen cut-point - a measure for activity level and not for SB or posture, and the cut-points performed better to detect task effects than workplace effects. Waist cut-points were most valid to measure the activity level in conventional seated office work, but they showed severe limitations for sit-stand desks. None of the placements was valid to detect the increased activity on the activity-promoting chair. Caution should therefore be paid when analysing the effect of workplace interventions on activity level with ActiGraph waist and wrist cut-points.

The Stability of the Gross Motor Function Classification System in Children with Cerebral Palsy Living in Stockholm and Factors Associated with Change.

AIM: To determine the degree of stability in the Gross Motor Function Classification System (GMFCS) for children with cerebral pares (CP) and to analyze factors associated with changes of the over time, in Stockholm between the year 2000 and 2019. METHOD: A register study on 768 children with at least two GMFCS ratings, linear regression analysis was used to study factors associated to a change in GMFCS level. RESULTS: 72% of the children kept the same GMFCS level. A change in GMFCS level was most common for children in GMFCS level II (68%). The first change in GMFCS level happened most commonly between the ages 2 and 4. Initial GMFCS level (Beta 0.127; p < 0.001) and one or more intensive training periods with a physiotherapist (Beta 0.097; p = 0.018) were associated with a change in GMFCS level. INTERPRETATION: Most children with CP remain stable in their GMFCS level, but for those classified in level II, a change occurs for almost seven out of ten. Classifications made before the child turns four are less certain than those made later. Further studies are needed to clarify if occurrence of intensive training is the cause or result of the change in GMFCS level.

Detecting prolonged sitting bouts with the ActiGraph GT3X.

The ActiGraph has a high ability to measure physical activity; however, it lacks an accurate posture classification to measure sedentary behavior. The aim of the present study was to develop an ActiGraph (waist-worn, 30 Hz) posture classification to detect prolonged sitting bouts, and to compare the classification to proprietary ActiGraph data. The activPAL, a highly valid posture classification device, served as reference criterion. Both sensors were worn by 38 office workers over a median duration of 9 days. An automated feature selection extracted the relevant signal information for a minute-based posture classification. The machine learning algorithm with optimal feature number to predict the time in prolonged sitting bouts (≥5 and ≥10 minutes) was searched and compared to the activPAL using Bland-Altman statistics. The comparison included optimized and frequently used cut-points (100 and 150 counts per minute (cpm), with and without low-frequency-extension (LFE) filtering). The new algorithm predicted the time in prolonged sitting bouts most accurate (bias ≤ 7 minutes/d). Of all proprietary ActiGraph methods, only 150 cpm without LFE predicted the time in prolonged sitting bouts non-significantly different from the activPAL (bias ≤ 18 minutes/d). However, the frequently used 100 cpm with LFE accurately predicted total sitting time (bias ≤ 7 minutes/d). To study the health effects of ActiGraph measured prolonged sitting, we recommend using the new algorithm. In case a cut-point is used, we recommend 150 cpm without LFE to measure prolonged sitting and 100 cpm with LFE to measure total sitting time. However, both cpm cut-points are not recommended for a detailed bout analysis.

Exercise-Induced Neuroplasticity in Parkinson's Disease: A Metasynthesis of the Literature.

Parkinson's disease (PD) is a neurodegenerative disorder for which there is currently only symptomatic treatment. During the last decade, there has been an increased interest in investigating physical exercise as a neuroprotective mechanism in PD. Animal studies have suggested that exercise may in fact induce neuroplastic changes, but evidence in humans is still scarce. A handful of reviews have previously reported on exercise-induced neuroplasticity in humans with PD, but few have been systematic, or have mixed studies on both animals and humans, or focused on one neuroplastic outcome only. Here, we provide a systematic review and metasynthesis of the published studies on humans in this research field where we have also included different methods of evaluating neuroplasticity. Our results indicate that various forms of physical exercise may lead to changes in various markers of neuroplasticity. A narrative synthesis suggests that brain function and structure can be altered in a positive direction after an exercise period, whereas a meta-analysis on neurochemical adaptations after exercise points in disparate directions. Finally, a GRADE analysis showed that the current overall level of evidence for exercise-induced neuroplasticity in people with PD is very low. Our results demonstrate that even though the results in this area point in a positive direction, researchers need to provide studies of higher quality using more rigorous methodology.

Is active sitting as active as we think?

The aim of this study was to compare the biomechanical characteristics of sitting on a stool without a backrest (so as to encourage active sitting), sitting on a conventional office chair and standing in healthy participants. Thirteen healthy participants performed a keyboard-writing task during four (stable and unstable) sitting conditions and standing. Body segment positions and posture, postural sway and muscle activity of neck and trunk muscles were assessed with a motion capture system, a force plate and surface electromyography. The results showed that body segment positions, postural sway and trunk muscle activity were relatively similar for the stools without backrests compared with standing. All sitting conditions showed lower vertical upper body alignment, less anterior pelvic tilt and larger hip angles, compared with standing (p = 0.000). Unexpectedly, the muscle activity levels and total postural sway, sway velocity and sway in M/L and A/P directions were lower (p = 0.000) for the conditions that encouraged active sitting and standing, compared with the conventional office chair conditions. PRACTITIONER SUMMARY: Thirteen healthy participants performed a keyboard-writing task during different sitting conditions and standing and were analysed regarding posture, postural sway and trunk muscle activity. Surprisingly, less postural sway and less muscle activity were observed during the conditions that encourage active sitting, compared with sitting on a conventional office chair.

The Effect of Therapeutic Exercise on Body Weight Distribution, Balance, and Stifle Function in Dogs following Stifle Injury.

Stifle injury is common in the companion dog population, affecting weight bearing, neuromuscular control, and balance. Therapeutic exercises after stifle injury seem to be effective, but high-quality research evaluating the effects is lacking. This randomized controlled trial evaluated the effects of a 12-week progressive therapeutic home exercise protocol on three-legged standing, targeting balance and postural- and neuromuscular control and disability in dogs with stifle injury. Thirty-three dogs with stifle injury were randomly allocated to intervention (n = 18) and control groups (n = 15), both receiving a standard rehabilitation protocol. Additionally, the intervention group received a progressive therapeutic exercise protocol. The outcome measures were static body weight distribution between hindlimbs, balance control, the canine brief pain inventory, and the Finnish canine stifle index. Both groups improved after the intervention period, but the group using the progressive therapeutic exercise protocol improved to a greater extent regarding static body weight distribution between the hindlimbs (I: median = 2.5%, IQR = 1.0-4.5; C: median = 5.5%, IQR = 3.0-8.8), pain-related functional disability (I: median = 0.0, IQR = 0.0-0.2; C: median = 0.9, IQR = 0.1-1.8), and stifle function (I: median = 25.0, IQR = 9.4-40.6; C: median = 75.0, IQR = 31.3-87.5), with intermediate to strong effects. These clinically relevant results indicate that this home exercise program can improve hindlimb function and restore neuromuscular control.

Mapping information regarding the work-related disability of depression and long-term musculoskeletal pain to the International Classification of Functioning, Disability and Health and ICF Core Sets.

Introduction: The International Classification of Functioning, Disability and Health is the WHO coding scheme for functioning-related data. Clear and unambiguous information regarding patients' work-related disabilities is important not only for the assessment of entitlement to paid sickness benefits but also for planning rehabilitation and return to work. The objective was to validate the content of ICF and ICF Core Sets for information on work-related disability in sick leave due to depression and long-term musculoskeletal pain. Specific aims: To describe to what extent (1) such data could be linked to ICF and (2) the result of the ICF linking in terms of ICF categories was represented in relevant ICF Core Sets. Methods: An ICF-linking study following the ICF-linking rules. A random sample of sick leave certificates issued in primary care for either depression (n = 25) or long-term musculoskeletal pain (n = 34) was collected from a community with 55,000 inhabitants in Stockholm County, Sweden. Results: The results of the ICF linking consisted of codings for (1) ICF categories and (2) other health information not possible to link to ICF. The ICF categories were compared to ICF Core Sets for coverage. The majority of the meaning units, 83% for depression and 75% for long-term musculoskeletal pain, were linked to ICF categories. The Comprehensive ICF Core Set for depression covered 14/16 (88%) of the ICF categories derived from the ICF linking. The corresponding figures were lower for both the Brief ICF Core Set for depression 7/16 (44%) and ICF Core Set for disability evaluation in social security 12/20 (60%). Conclusion: The results indicates that ICF is a feasible code scheme for categorising information on work-related disability in sick leave certificates for depression and long-term musculoskeletal pain. As expected, the Comprehensive ICF Core Set for depression covered the ICF categories derived from the certificates for depression to a high degree. However, the results indicate that (1) sleep- and memory functions should be added to the Brief ICF Core Set for depression, and (2) energy-, attention- and sleep functions should be added to the ICF Core Set for disability evaluation in social security when used in this context.

Effects of weight-shift training on balance control and weight distribution in chronic stroke: a pilot study.

PURPOSE: The objective was to evaluate the effect of weight-shift training on functional balance, weight distribution, and postural control measures during standing and forward reach tasks in subjects with chronic stroke. METHODS: Nine male subjects (mean age, 66 years; range, 60-75 years) who experienced a stroke 3 to 13 years previously participated in a 4-week training program consisting of static and dynamic balance exercises with visual feedback and gait training with wall support. Balance control was assessed before and after the intervention with clinical measures (Berg Balance Scale) and with a pressure platform for registering the center of pressure (CoP) during quiet stance (weight distribution, CoP sway area, and velocity), and during a forward reach task at shoulder and knee levels. Intervention effects were evaluated with the Wilcoxon matched-pairs test. RESULTS: After training, the group improved their Berg Balance Scale median score from 42 (range, 14-54) to 46 (20-55) (P = .01), CoP sway area [10.6 (5.0-31.4) to 3.0 (1.8-10.8) cm2; P = .01], and mean velocity [3.5 (2.4-8.0) to 1.7 (0.9-3.7) mm/s; P = .01] during quiet standing but not weight distribution (P = .59). During the forward reach tasks, most of the postural control measures such as movement time, CoP displacement, and CoP velocity were significantly (P < .05) improved after the training period for both the affected and nonaffected sides as compared to before the training period. CONCLUSION: A weight-shift training program improved balance control but not weight distribution in a group of chronic stroke subjects. Larger, randomized, and controlled studies are necessary.

How Accurate and Precise Can We Measure the Posture and the Energy Expenditure Component of Sedentary Behaviour with One Sensor?

Sedentary behaviour is an emergent public health topic, but there is still no method to simultaneously measure both components of sedentary behaviour-posture and energy expenditure-with one sensor. This study investigated the accuracy and precision of measuring sedentary time when combining the proprietary processing of a posture sensor (activPAL) with a new energy expenditure algorithm and the proprietary processing of a movement sensor (ActiGraph) with a published posture algorithm. One hundred office workers wore both sensors for an average of 7 days. The activPAL algorithm development used 38 and the subsequent independent method comparison 62 participants. The single sensor sedentary estimates were compared with Bland-Atman statistics to the Posture and Physical Activity Index, a combined measurement with both sensors. All single-sensor methods overestimated sedentary time. However, adding the algorithms reduced the overestimation from 129 to 21 (activPAL) and from 84 to 7 min a day (ActiGraph), with far narrower 95% limits of agreements. Thus, combining the proprietary data with the algorithms is an easy way to increase the accuracy and precision of the single sensor sedentary estimates and leads to sedentary estimates that are more precise at the individual level than those of the proprietary processing are at the group level.

Self-Reported and Device-Measured Physical Activity in Leisure Time and at Work and Associations with Cardiovascular Events-A Prospective Study of the Physical Activity Paradox.

The beneficial health effects of physical activity, in particular moderate-to-vigorous physical activity (MVPA), are well documented, but there is an ongoing scientific debate whether the domain matters, i.e., whether leisure time physical activity is beneficial and occupational physical activity is detrimental to health, referred to as the physical activity paradox. The present study, therefore, analyzed the association between self-reported and device-measured physical activity and cardiovascular events in both domains. A representative sample of 807 individuals was followed for 14.6 ± 1.1 years, in which 59 cardiovascular events occurred. For self-reported data, Cox proportional hazard models showed no effect of physical activity in leisure and at work, while for device-measured MVPA, beneficial associations with total time spent in MVPA and occupational time spent in MVPA were found, but not for leisure time spent in MVPA. When accounting for both domains in the same model, the associations disappeared. These results indicate that it matters how physical activity is measured and that MVPA is beneficial for cardiovascular health, but the domain in which MVPA occurs does not seem to matter.

Is Sitting Always Inactive and Standing Always Active? A Simultaneous Free-Living activPal and ActiGraph Analysis.

Sedentary Behavior (SB), defined as sitting with minimal physical activity, is an emergent public health topic. However, the measurement of SB considers either posture (e.g., activPal) or physical activity (e.g., ActiGraph), and thus neglects either active sitting or inactive standing. The aim of this study was to determine the true amount of active sitting and inactive standing in daily life, and to analyze by how much these behaviors falsify the single sensors' sedentary estimates. Sedentary time of 100 office workers estimated with activPal and ActiGraph was therefore compared with Bland-Altman statistics to a combined sensor analysis, the posture and physical activity index (POPAI). POPAI classified each activPal sitting and standing event into inactive or active using the ActiGraph counts. Participants spent 45.0% [32.2%-59.1%] of the waking hours inactive sitting (equal to SB), 13.7% [7.8%-21.6%] active sitting, and 12.0% [5.7%-24.1%] inactive standing (mean [5th-95th percentile]). The activPal overestimated sedentary time by 30.3% [12.3%-48.4%] and the ActiGraph by 22.5% [3.2%-41.8%] (bias [95% limit-of-agreement]). The results showed that sitting is not always inactive, and standing is not always active. Caution should therefore be paid when interpreting the activPal (ignoring active sitting) and ActiGraph (ignoring inactive standing) measured time as SB.

Prognostic factors for improved physical and emotional functioning one year after interdisciplinary rehabilitation in patients with chronic pain: Results from a national quality registry in Sweden.

OBJECTIVE: To investigate prognostic factors for physical and emotional functioning following interdisciplinary multimodal pain rehabilitation, by targeting patients' baseline characteristics and health measures. METHODS: A prospective cohort of 2,876 patients from 38 specialist clinics across Sweden, who were completing interdisciplinary multimodal pain rehabilitation programmes, was followed through the Swedish Quality Registry for Pain Rehabilitation, from initial assessment to 12-month follow-up. Using logistic regression, baseline data were regressed to predict improvement in Physical functioning and Emotional functioning, fused by principal component analyses using the 36-item Short Form Health Survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS). RESULTS: Employment status emerged as having the largest effect sizes in both Physical functioning and Emotional functioning; Working: odds ratio (OR) 2.05 (95% confidence interval (95% CI) 1.64-2.56) and OR 1.59 (95% CI 1.27-1.98), respectively. Strong beliefs in restored health, better initial emotional health, lower levels of pain and pain interference, and younger age all predicted Physical functioning. European origin, higher levels of general activity, and sense of life control all predicted Emotional functioning. Worse initial physical and emotional health predicted the corresponding dependent outcomes. CONCLUSION: Employment was consistently found to be an important prognostic factor, suggesting the significance of avoiding delay in interdisciplinary multimodal pain rehabilitation. A positive treatment expectancy was of importance. In general, multidimensional measures indicated that better initial status was more favourable; however, inconsistency implies a complex prognostic picture.

Prognostic Factors for Physical Functioning After Multidisciplinary Rehabilitation in Patients With Chronic Musculoskeletal Pain: A Systematic Review and Meta-Analysis.

OBJECTIVES: This systematic review aimed to identify and evaluate prognostic factors for long-term (≥6 mo) physical functioning in patients with chronic musculoskeletal pain following multidisciplinary rehabilitation (MDR). MATERIALS AND METHODS: Electronic searches conducted in MEDLINE, PsycINFO, EMBASE, CINAHL, Web of Science, and Cochrane CENTRAL revealed 25 original research reports, published 1983-2016, (n=9436). Potential prognostic factors relating to initial pain and physical and psychological functioning were synthesized qualitatively and quantitatively in random effects meta-analyses. The level of evidence (LoE) was evaluated with Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: Pain-related factors (intensity and chronicity) were not associated with function/disability at long-term follow-up, odds ratio (OR)=0.84; 95% confidence interval (CI), 0.65-1.07 and OR=0.97; 95% CI, 0.93-1.00, respectively (moderate LoE). A better function at follow-up was predicted by Physical factors; higher levels of initial self-reported functioning, OR=1.07; 95% CI, 1.02-1.13 (low LoE), and Psychological factors; low initial levels of emotional distress, OR=0.77; 95% CI, 0.65-0.92, low levels of cognitive and behavioral risk factors, OR=0.85; 95% CI, 0.77-0.93 and high levels of protective cognitive and behavioral factors, OR=1.49; 95% CI, 1.17-1.90 (moderate LoE). DISCUSSION: While pain intensity and long-term chronicity did not predict physical functioning in chronic pain patients after MDR, poor pretreatment physical and psychological functioning influenced the prognosis negatively. Thus, treatment should further target and optimize these modifiable factors and an increased focus on positive, psychological protective factors may perhaps provide an opening for yet untapped clinical gains.

How does exercise dose affect patients with long-term osteoarthritis of the knee? A study protocol of a randomised controlled trial in Sweden and Norway: the SWENOR Study.

INTRODUCTION: Osteoarthritis (OA) of the knee is characterised by knee pain, disability and degenerative changes, and places a burden on societies all over the world. Exercise therapy is an often-used modality, but there is little evidence of what type of exercise dose is the most effective, indicating a need for controlled studies of the effect of different dosages. Thus, the aim of the study described in this protocol is to evaluate the effects of high-dose versus low-dose medical exercise therapy (MET) in patients with knee OA. METHODS AND ANALYSIS: This is a multicentre prospective randomised two-arm trial with blinded assessment and data analysis. We are planning to include 200 patients aged 45-85 years with symptomatic (pain and decreased functioning) and X-ray verified diagnosis of knee OA. Those eligible for participation will be randomly allocated to either high-dose (n=100) or low-dose (n=100) MET. All patients receive three supervised treatments each week for 12 weeks, giving a total of 36 MET sessions. The high-dose group exercises for 70-90 min compared with 20-30 min for the low-dose group. The high-dose group exercises for a longer time, and receives a greater number of exercises with more repetitions and sets. Background and outcome variables are recorded at inclusion, and outcome measures are collected after every sixth treatment, at the end of treatment, and at 6-month and 12-month follow-ups. Primary outcome is self-rated knee functioning and pain using the Knee Injury and Osteoarthritis Outcome Score (KOOS). The primary end point is at the end of treatment after 3 months, and secondary end points are at 6 months and 12 months after the end of treatment. ETHICS AND DISSEMINATION: This project has been approved by the Regional Research Ethics Committees in Stockholm, Sweden, and in Norway. Our results will be submitted to peer-reviewed journals and presented at national and international conferences. TRIAL REGISTRATION NUMBER: NCT02024126; Pre-results.

Low levels of physical activity in back pain patients are associated with high levels of fear-avoidance beliefs and pain catastrophizing.

BACKGROUND AND PURPOSE: Fear-avoidance beliefs are important determinants for disability in patients with non-specific low-back pain (LBP). The association with self-reported level of physical activity is less known. The aim of the present study was to describe the level of physical activity in patients with chronic non-specific LBP and its relation to fear-avoidance beliefs and pain catastrophizing. METHOD: A cross-sectional study on 64 patients with chronic non-specific LBP in primary healthcare. The variables measured and the questionnaires used were: level of physical activity (six-graded scale); activity limitations (Roland Morris Disability Questionnare (RDQ)); fear-avoidance beliefs (Tampa Scale of Kinesiophobia (TSK) 13-item and sub-scales 'activity avoidance' and 'somatic focus'); and pain catastrophizing (Pain Catastrophizing Scale (PCS)). The level of physical activity was dichotomised into low and high physical activity. Individual median scores on the TSKandPCSscales were used to group the patients into different levels offear-avoidance beliefs and pain catastrophizing. Univariate logistic regressions were used to calculate odds ratios for having low physical activity. RESULTS: Patients with low physical activity had significantly higher scores in fear-avoidance beliefs and pain catastrophizing (p < 0.05). Odds ratios for low level of physical activity were between 4 and 8 (p < 0.05) for patients with high fear-avoidance beliefs or medium/high pain catastrophizing. CONCLUSIONS: This study indicates that it seems important for physiotherapists in primary care to measure levels of fear-avoidance beliefs or pain catastrophizing. In particular, the two subscales of the TSK could be of real value for clinicians when making treatment decisions concerning physical exercise therapy for patients with chronic LBP.

An iPhone application for upper arm posture and movement measurements.

There is a need for objective methods for upper arm elevation measurements for accurate and convenient risk assessments. The aims of this study were (i) to compare a newly developed iOS application (iOS) for measuring upper arm elevation and angular velocity with a reference optical tracking system (OTS), and (ii) to compare the accuracy of the iOS incorporating a gyroscope and an accelerometer with using only an accelerometer, which is standard for inclinometry. The iOS-OTS limits of agreement for static postures (9 subjects) were -4.6° and 4.8°. All root mean square differences in arm swings and two simulated work tasks were <6.0°, and all mean correlation coefficients were >0.98. The mean absolute iOS-OTS difference of median angular velocity was <13.1°/s, which was significantly lower than only using an accelerometer (<43.5°/s). The accuracy of this iOS application compares well to that of today's research methods and it can be useful for practical upper arm measurements.

The McMaster Toronto Arthritis patient preference questionnaire (MACTAR): a methodological study of reliability and minimal detectable change after a 6 week-period of acupuncture treatment in patients with rheumatoid arthritis.

OBJECTIVES: The McMaster Toronto Arthritis patient preference questionnaire (MACTAR) is a semi-structured interview consisting of a baseline and a follow-up interview. The MACTAR baseline is reliable and valid, however the reliability of the MACTAR follow-up is scarcely described. The aim of this study was to describe aspects of reliability and ability to detect changes of the Swedish MACTAR follow-up following acupuncture treatment in individuals with rheumatoid arthritis. RESULTS: The study was of Single Subject Experimental Design, with a 2-week non-interventional A-phase and a 6-week intervention B-phase. Eight individuals with RA, age 30-68 years, were included. MACTAR baseline was performed once followed by five assessments with MACTAR follow-up during the A-phase and another ten assessments during the B-phase. Reliability statistics were calculated for measurements 1-3 during the A-phase and the ability to detect effects of acupuncture treatment was tested by celeration lines in the B-phase. The MACTAR follow-up was highly reliable (ICC = 0.7-0.9, SEM = 2.3-4.3, and SDD = 6.2-11.7). Visual and statistical analyses indicated that the MACTAR follow-up could detect effects on individual- and group levels after acupuncture treatment, indicating that the MACTAR follow-up seems to be reliable and is able to detect effects of acupuncture treatment in RA.

Does a dynamic chair increase office workers' movements? - Results from a combined laboratory and field study.

PURPOSE: Dynamic chairs have the potential to facilitate movements that could counteract health problems associated with sedentary office work. This study aimed to evaluate whether a dynamic chair can increase movements during desk-based office work. METHODS: Fifteen healthy subjects performed desk-based office work using a dynamic office chair and compared to three other conditions in a movement laboratory. In a field study, the dynamic office chair was studied during three working days using accelerometry. RESULTS: Equivocal results showed that the dynamic chair increased upper body and chair movements as compared to the conventional chair, but lesser movements were found compared to standing. No differences were found between the conditions in the field study. CONCLUSIONS: A dynamic chair may facilitate movements in static desk-based office tasks, but the results were not consistent for all outcome measures. Validation of measuring protocols for assessing movements during desk-based office work is warranted.

Are job strain and sleep disturbances prognostic factors for low-back pain?A cohort study of a general population of working age in Sweden.

The aim of this study was to determine whether job strain, i.e. a combination of job demands and decision latitude (job control), and sleep disturbances among persons with occasional low-back pain are prognostic factors for developing troublesome low-back pain; and to determine whether sleep disturbances modify the potential association between job strain and troublesome low-back pain. A population-based cohort from the Stockholm Public Health Cohort surveys in 2006 and 2010 (= 25,167) included individuals with occasional low-back pain at baseline 2006 (= 6,413). Through logistic regression analyses, potential prognostic effects of job strain and sleep disturbances were studied. Stratified analyses were performed to assess modification of sleep disturbances on the potential association between job strain and troublesome low-back pain. Those exposed to job strain; active job (odds ratio (OR) 1.3, 95% confidence interval (95% CI) 1.1-1.6), or high strain (OR 1.5, 95% CI 0.9-2.4) and those exposed to severe sleep disturbances (OR 3.0, 95% CI 2.3-4.0), but not those exposed to passive jobs (OR 1.1, 95% CI 0.9-1.4) had higher odds of developing troublesome low-back pain. Sleep disturbances did not modify the association between job strain and troublesome low-back pain. These findings indicate that active job, high job strain and sleep disturbances are prognostic factors for troublesome low-back pain. The odds of developing troublesome low-back pain due to job strain were not modified by sleep disturbance.

Nonsteroidal Anti-inflammatory Drugs for Sciatica: An Updated Cochrane Review.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To determine the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) on pain reduction, overall improvement, and reported adverse effects in people with sciatica. SUMMARY OF BACKGROUND DATA: NSAIDs are one of the most frequently prescribed drugs for sciatica. METHODS: We updated a 2008 Cochrane Review through June 2015. Randomized controlled trials that compared NSAIDs with placebo, with other NSAIDs, or with other medication were included. Outcomes included pain using mean difference (MD, 95% confidence intervals [95% CI]). For global improvement and adverse effects risk ratios (RR, 95% CI) were used. We assessed level of evidence using the Grades of Recommendation, Assessment, Development and Evaluation approach. RESULTS: Ten trials were included (N = 1651). Nine out of 10 trials were assessed at high risk of bias. For pain reduction (visual analog scale, 0 to 100) NSAIDs were no more effective than placebo (MD -4.56, 95% CI -11.11 to 1.99, quality of evidence: very low). For global improvement NSAIDs were more effective than placebo (RR 1.14 [95% CI 1.03 to 1.27], low quality of evidence). One trial reported the effect of NSAIDs on disability with very low-quality evidence that NSAIDs are no more effective than placebo. There was low-quality evidence that the risk for adverse effects is higher for NSAID than placebo (RR 1.40, 95% CI 1.02 to 1.93). CONCLUSION: Our findings show very low-quality evidence that the efficacy of NSAIDs for pain reduction is comparable with that of placebo, low-quality evidence that NSAIDs is better than placebo for global improvement and low-quality evidence for higher risk of adverse effects using NSAIDs compared with placebo. The findings must be interpreted with caution, due to small study samples, inconsistent results, and a high risk of bias in the included trials. LEVEL OF EVIDENCE: 1.