Association between sitting and occupational LBP

Do different sitting postures affect spinal biomechanics of asymptomatic individuals?

BACKGROUND

Static sitting is thought to be related to low back pain. Of various common seated postures, slouched sitting has been suggested to cause viscoelastic creep. This, in turn, may compromise trunk muscle activity and proprioception, and heightening the risk of low back pain. To date, no research has evaluated immediate and short-term effects of brief exposures to different sitting postures on spinal biomechanics and trunk proprioception.

RESEARCH QUESTION

This study aimed to compare the impacts of 20 min of static slouched, upright and supported sitting with a backrest on trunk range of motion, muscle activity, and proprioception immediately after and 30 min after the sitting tasks.

METHODS

Thirty-seven adults were randomly assigned to the three sitting posture groups. Surface electromyography of six trunk muscles during maximum voluntary contractions were measured at baseline for normalization. Pain intensity, lumbar range of motion, and proprioceptive postural control strategy were assessed at baseline, 20 min (immediately post-test) and at 50 min (recovery). Trunk muscle activity during sitting was continuously monitored by surface electromyography.

RESULTS

While the slouched sitting group demonstrated the lowest bilateral obliquus internus/transversus abdominis activity as compared to other sitting postures (F = 4.87, p < 0.05), no significant temporal changes in pain intensity, lumbar range of motion nor proprioceptive strategy were noted in any of the groups.

SIGNIFICANCE

Sitting for 20 min of duration appears to have no adverse effects on symptoms or spinal biomechanics regardless of the posture adopted. Future research should determine if there is a point at which does slouched sitting cause significant changes in pain/spinal biomechanics in people both with and without low back pain.

Influences of continuous sitting and psychosocial stress on low back kinematics, kinetics, discomfort, and localized muscle fatigue during unsupported sitting activities

Continuous seated postures may increase the risk of adverse health outcomes such as low-back pain, and this risk may be influenced by several modifying factors. In the present study, we aimed to quantify the effects of continuous sitting and psychosocial stress under an unsupported sitting condition. Fourteen participants completed continuous, 40 min. periods of computer-based tasks, involving both low and higher levels of psychosocial stress, while using a laptop computer without a desk. Continuous sitting significantly increased perceived discomfort (particularly in the upper and lower back), trunk flexion and metrics of localized muscle fatigue. A higher level of psychosocial stress increased estimated lumbosacral compression forces (by ∼12%). Only weak correlations were found between subjective and objective measures, while various fatigue metrics showed a good level of correspondence with each other. These results could support the future evaluation or design of diverse seated work configurations. Practitioner Summary: Continuous, 40 min. periods of unsupported sitting had broad impacts on subjective and objective outcomes, including discomfort, postures, spine loads and localized muscle fatigue, while psychosocial stress only had a substantial influence on lumbosacral compression. These results extend our understanding of sitting behaviors and provide information for designing future sitting environments.

Active sitting with backrest support: Is it feasible?

Ergonomics science recommends office chairs that promote active sitting to reduce sitting related complaints. Since current office chairs do not fulfill this recommendation, a new chair was developed by inverting an existing dynamic chair principle. This study compares active sitting on the inverted chair during a simulated computer-based office task to two existing dynamic office chairs (n = 8). Upper body stability was analysed using Friedman ANOVA (p = .01). In addition, participants completed a questionnaire to rate their comfort and activity after half a working day. The inverted chair allowed the participants to perform a substantial range of lateral spine flexion (11.5°) with the most stable upper body posture (≤11 mm, ≤2°, p ≤ .01). The results of this study suggest that the inverted chair supports active sitting with backrest support during computer-based office work. However, according to comfort and activity ratings, results should be verified in a future field study with 24 participants. Practitioner Summary: This experimental laboratory study analyses the feasibility of active sitting with a backrest support during common office work on a new type of dynamic office chair. The results demonstrate that active sitting with a backrest support is feasible on the new but limited on existing chairs.

Low cost self-made pressure distribution sensors for ergonomic chair: Are they suitable for posture monitoring?

BACKGROUND

Long sitting causes many health problems for people. Healthy sitting monitoring systems, like real-time pressure distribution measuring, is in high demand and many methods of posture recognition were developed. Such systems are usually expensive and hardly available for the regular user.

OBJECTIVE

The aim of study is to develop low cost but sensitive enough pressure sensors and posture monitoring system.

METHODS

New self-made pressure sensors have been developed and tested, and prototype of pressure distribution measuring system was designed.

RESULTS

Sensors measured at average noise amplitude of a = 56 mV (1.12%), average variation in sequential measurements of the same sensor s = 17 mV (0.34%). Signal variability between sensors averaged at 100 mV (2.0%). Weight to signal dependency graph was measured and hysteresis calculated. Results suggested the use of total sixteen sensors for posture monitoring system with accuracy of < 1.5% after relaxation and repeatability of around 2%.

CONCLUSION

Results demonstrate that hand-made sensor sensitivity and repeatability are acceptable for posture monitoring, and it is possible to build low cost pressure distribution measurement system with graphical visualization without expensive equipment or complicated software.

Twenty Thousand Needles Under the Sea. Trigger Point Dry Needling Aboard an Israeli Navy Submarine: A Case Report

Nonspecific lower back pain affects a major part of the population at a certain point of their life. The intensity of pain can be debilitating and it causes a significant burden on society. Trigger point dry needling is a method of alleviating such pain by the introduction of needles into trigger points in muscles. A growing body of evidence supports its use in myofascial pain and specifically lower back pain. Submarine Medicine is a unique field due to the special characteristics and the environment of the submarine. It poses challenges that are not always seen by primary care physicians. Here, we present a case of a 40-yr-old senior submarine officer who complained of pain in his lower back and pelvis before departing on a mission. The pain persisted in spite of treatment with nonsteroidal anti-inflammatory drugs and he was then treated by the submarine's physician with trigger point dry needling. The officer showed rapid improvement following this treatment, both regarding pain and the range of motion.

Longer sitting time and low physical activity are closely associated with chronic low back pain in population over 50 years of age: a cross-sectional study using the sixth Korea National Health and Nutrition Examination Survey

BACKGROUND CONTEXT

There is increasing evidence supporting an association between sitting time and low back pain (LBP). However, the degree of the association between the total daily sitting time and LBP in the general population is poorly understood.

PURPOSE

The present study aimed (1) to analyze the association between the duration of sitting time and LBP, and (2) to examine this association according to the degree of physical activity in population over 50 years of age with a nationally representative sample of Korean adults.

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

Data from version VI-2, 3 of the Korea National Health and Nutrition Examination Survey (KNHANES) performed in 2014 and 2015 were analyzed.

OUTCOME MEASURES

Multiple logistic regression was performed to find the rates of association between chronic LBP, level of sitting time, and physical activity.

METHODS

Nationwide health surveys and examinations were conducted in general Korean representative populations (n=7,550 in 2014, n=7,380 in 2015). Chronic LBP was defined as self-reported LBP lasting for more than 30 days during the past 3 months in a health survey. Sitting time and daily physical activity were evaluated using the long version of the International Physical Activity Questionnaires (IPAQ). The duration of sitting time was divided into two categories according to the median value (7 hours) and further divided into four categories using quartiles. Physical activity was also divided into low and high physical activity according to duration of mid- to high-intensity activities. There were no sources of funding and no conflicts of interest associated with the present study.

RESULTS

On multiple logistic regression analysis, sitting time more than 7 hours/day was significantly associated with LBP (adjusted odds ratio 1.33, p<.001). The risk of LBP increased with increasing duration of sitting time. In participants with low levels of physical activity, the duration of sitting time showed more positive association with LBP than that in all the participants and participants with high levels of physical activity.

CONCLUSIONS

Longer duration of sitting time is a risk factor for LBP. Furthermore, long duration of sitting time with low physical activity further increases the risk of LBP.

Effect of in-seat exercising on comfort perception of airplane passengers

Sitting still for extended periods of time can lead to physical discomfort and even serious health risks. Due to safety regulations, reducing passenger' sitting time in aircrafts is not feasible. This paper presents the results of a laboratory study, in where an interactive airplane seat was compared with a current economy class seat. Participants used both seats for 3.5 h, and performed significantly more in-seat movements when using the interactive seating system. Furthermore, this interactive seat predominantly lead to significantly better comfort experiences and reduced discomfort experiences, however no significant differences have been found in self-reported localized musculoskeletal discomfort. Passengers indicated that they would prefer this interactive seat over a standard aircraft seat.

Determination of a sagittal plane axis of rotation for a dynamic office chair

OBJECTIVE

This study investigated the location of the axis of rotation in sagittal plane movement of the spine in a free sitting condition to adjust the kinematics of a mobile seat for a dynamic chair.

BACKGROUND

Dynamic office chairs are designed to avoid continuous isometric muscle activity, and to facilitate increased mobility of the back during sitting. However, these chairs incorporate increased upper body movement which could distract office workers from the performance of their tasks. A chair with an axis of rotation above the seat would facilitate a stable upper back during movements of the lower back. The selection of a natural kinematic pattern is of high importance in order to match the properties of the spine.

METHOD

Twenty-one participants performed four cycles of flexion and extension of the spine during an upper arm hang on parallel bars. The location of the axis of rotation relative to the seat was estimated using infrared cameras and reflective skin markers.

RESULTS

The median axis of rotation across all participants was located 36 cm above the seat for the complete movement and 39 cm for both the flexion and extension phases, each with an interquartile range of 20 cm.

CONCLUSION

There was no significant effect of the movement direction on the location of the axis of rotation and only a weak, non-significant correlation between body height and the location of the axis of rotation. Individual movement patterns explained the majority of the variance.

APPLICATION

The axis of rotation for a spinal flexion/extension movement is located above the seat. The recommended radius for a guide rail of a mobile seat is between 36 cm and 39 cm.

Factors predisposing to work-related lower back pain in automobile industry workers

Objective. This study aimed to assess the presence of lower back pain (LBP) in automobile industrial workers and correlate it with the factors known to be contributing to the development of work-related LBP. Method. Post ethical approval, an analytical cross-sectional assessment was conducted for a correlation study on 317 workers from different automobile industries, garages and service centres, who were then assessed by Nordic musculoskeletal questionnaire for the presence of LBP. Their pain intensity was assessed using a numerical rating scale, their core strength with a pressure biofeedback unit, their flexibility via the sitting and reach test and their work posture with the rapid entire body assessment tool. Pain intensity was correlated with core strength, flexibility and posture in all of the workers using Spearman's correlation coefficient r with α set at p ≤ 0.05 at a 95% confidence interval. Results. There was no significant correlation of the pain intensity with the core strength (r = 0.052, p = 0.424), flexibility (r = 0.020, p = 0.755) or posture (r = 0.002, p = 0.974). Conclusion. The present study indicates that internal factors like core strength and flexibility, and work postures have no correlation with intensity and severity of LBP in automobile industry workers.

A Scene Recognition and Semantic Analysis Approach to Unhealthy Sitting Posture Detection during Screen-Reading

Behavior analysis through posture recognition is an essential research in robotic systems. Sitting with unhealthy sitting posture for a long time seriously harms human health and may even lead to lumbar disease, cervical disease and myopia. Automatic vision-based detection of unhealthy sitting posture, as an example of posture detection in robotic systems, has become a hot research topic. However, the existing methods only focus on extracting features of human themselves and lack understanding relevancies among objects in the scene, and henceforth fail to recognize some types of unhealthy sitting postures in complicated environments. To alleviate these problems, a scene recognition and semantic analysis approach to unhealthy sitting posture detection in screen-reading is proposed in this paper. The key skeletal points of human body are detected and tracked with a Microsoft Kinect sensor. Meanwhile, a deep learning method, Faster R-CNN, is used in the scene recognition of our method to accurately detect objects and extract relevant features. Then our method performs semantic analysis through Gaussian-Mixture behavioral clustering for scene understanding. The relevant features in the scene and the skeletal features extracted from human are fused into the semantic features to discriminate various types of sitting postures. Experimental results demonstrated that our method accurately and effectively detected various types of unhealthy sitting postures in screen-reading and avoided error detection in complicated environments. Compared with the existing methods, our proposed method detected more types of unhealthy sitting postures including those that the existing methods could not detect. Our method can be potentially applied and integrated as a medical assistance in robotic systems of health care and treatment.

Evaluating Short-Term Musculoskeletal Pain Changes in Desk-Based Workers Receiving a Workplace Sitting-Reduction Intervention

This paper explores changes in musculoskeletal pain among desk-based workers over three months of a workplace-delivered, sitting-reduction intervention. Participants (n = 153, 46% female; mean ± SD aged 38.9 ± 8.0 years) were cluster-randomized (n = 18 work teams) to receive an organizational change intervention, with or without an activity tracker. A modified Nordic Musculoskeletal Questionnaire assessed pain intensity (0–9; none–worst possible) in the neck, upper and lower back, upper and lower extremities, and in total. The activPAL3 (7 days, 24 h/day protocol) measured sitting and prolonged sitting in ≥30 min bouts at work. Mixed models adjusting for cluster and intervention arm examined changes in pain (n = 104), and their associations with reductions in sitting and prolonged sitting (h/10 h at work) (n = 90). Changes in pain were nonsignificant (p ≥ 0.05) and small for total pain (−0.06 [95% CI: −0.27, 0.16]) and for each body area (−0.26 [−0.66, 0.15] for upper back to 0.09 [−0.39, 0.56] for lower back). Sitting reduction was associated with reduced lower back pain (−0.84 [−1.44, −0.25] per hour, p = 0.005); other effects were small and non-significant. No substantial average changes in pain were seen; some improvement in lower back pain might be expected with larger sitting reductions. Larger samples and diverse interventions are required for more definitive evidence.

The effect of standing vs. variants of the seated position on lumbar intersegmental angulation and spacing: a radiographic study of 20 asymptomatic subjects

Background

Pain while sitting is the primary complaint of many patients with lumbar spinal ailments, including those with discogenic low back pain and lumbar disc herniations. There has been little basic research on the different mechanical stresses that different sitting positions place on the spine. To demonstrate the effect of different sitting positions on lumbar intersegmental relationships.

Methods

Twenty healthy male volunteer subjects were recruited. Lateral X-rays of the lower lumbar spine were taken in four positions: (I) relaxed lateral standing; (II) "standard" sitting position; (III) sitting on a "kneeling" chair; and (IV) unsupported sitting on a stool. Anterior and posterior disc height, disc space angulation, L1-S1 angulation and interspinous distance were measured.

Results

The L1-S1 lordotic angle in the standing position (48.8°±14.7°) was found to be statistically significantly greater than the angle measured with any of the sitting positions: the kneeling chair (34.0°±17.7°); hard-back chair (28.6°±14.3°); and the stool (16.6°±15.6°). Total average disc height (arithmetic sum of average disc heights L2-S1) in the lumbar spine varied with position: standing (40.5±7.75 mm); hard-back chair (38.5±6.9 mm); kneeling chair (38.4±7.9 mm); stool (36.9±7.1 mm). The mean interspinous distance over all the lumbar levels was significantly greater in each of the three seated positions than in the standing position: standing 6.8±4.5 mm; 11.6°±7.5° for the kneeling chair; 12.9±5.8 mm for the hard-back chair; 16.9±7.0 mm for the stool.

Conclusions

If segmental flexion and segmental loading are the important biomechanical correlates of pain on sitting, such patients should be most comfortable in a kneeling chair, which most closely approximates the standing position. These basic findings will allow better assessment of different seating positions from an ergonomic perspective, and hopefully lead to improvements in chair design.

Effect of Using a Sit-Stand Desk on Ratings of Discomfort, Fatigue, and Sleepiness Across a Simulated Workday in Overweight and Obese Adults

BACKGROUND

Limited research examines the influence of sit-stand desks on ratings of discomfort, sleepiness, and fatigue. This study evaluated the time course of these outcomes over 1 day.

METHODS

Adults (N = 25) completed a randomized cross-over study in a laboratory with two 8-hour workday conditions: (1) prolonged sitting (SIT) and (2) alternating sitting and standing every 30 minutes (SIT-STAND). Sleepiness was assessed hourly. Discomfort, physical fatigue, and mental fatigue were measured every other hour. Linear mixed models evaluated whether these measures differed across conditions and the workday. Effect sizes were calculated using Cohen's d.

RESULTS

Participants were primarily white (84%) males (64%), with mean (SD) body mass index of 31.9 (5.0) kg/m² and age 42 (12) years. SIT-STAND resulted in decreased odds of discomfort (OR = 0.37, P = .01) and lower overall discomfort (β = -0.19, P < .001, d = 0.42) versus SIT. Discomfort during SIT-STAND was lower in the lower and upper back, but higher in the legs (all Ps< .01, d = 0.26-0.42). Sleepiness (β = -0.09, P = .01, d = 0.15) and physical fatigue (β = -0.34, P = .002, d = 0.34) were significantly lower in SIT-STAND. Mental fatigue was similar across conditions.

CONCLUSIONS

Sit-stand desks may reduce acute levels of sleepiness, physical fatigue, and both overall and back discomfort. However, levels of lower extremity discomfort may be increased with acute exposure.

The influence of sleep disorders on the quality of life in patients with chronic low back pain

INTRODUCTION

Low back pain (LBP) is one of the most common pain syndromes, and its prevalence has increased significantly in the past three decades.

OBJECTIVES

The aim of this study was to evaluate the effects of insomnia and daytime sleepiness on the quality of life (QOL) of patients suffering from chronic back pain.

MATERIAL AND METHODS

It is a cross-sectional study conducted among 100 people (aged 25-75 years - mean age 49.53 ± 10.92) treated in a neurological clinic for chronic back pain lasting longer than 3 months. The diagnostic survey method was applied for the purposes of this study with the use of: the author's questionnaire and standardised questionnaires that is Visual Analogue Scale (VAS), Epworth Sleepiness Scale (ESS), Athens Insomnia Scale (AIS) and Polish version of WHO Quality of Life-BREF questionnaire (WHOQOL-BREF). The results were statistically analysed.

RESULTS

Analysis of the study material showed that 83% of patients suffered from insomnia (scored 6 or more points on the AIS) and 29% experienced mild daytime sleepiness. People who were more sleepy during the day were characterised by lower perception of the QOL (r = -0.034, p = 0.029) and lower perception of general health (r = -0.035, p = 0.04). Analysis of multiple variables (using linear regression) showed that independent predictor of the QOL in all domains is the result of the AIS questionnaire (p < 0.05).

CONCLUSIONS

Sleep disorders - both insomnia and daytime sleepiness - are a common health problem experienced by people with LBP. Insomnia is an important predictor affecting the QOL in people with LBP.

Impact of material properties of intervertebral disc on dynamic response of the human lumbar spine to vertical vibration: a finite element sensitivity study

This study aimed to determine the effect of variations in material properties of the intervertebral disc on dynamic response of the human lumbar spine to vertical vibration using a finite element model of the lumbar L1-S1 motion segment. The present material sensitivity study was conducted by varying elastic moduli for annulus ground substance (AGS), annulus fibers (AF), and nucleus pulposus (NP) in the disc. Transient dynamic analysis was performed initially on the model with basic material property under a sinusoidal vertical vibration load. Subsequently, the same analysis was done for each of the three disc components corresponding to high and low material property cases. The computed results were plotted as a function of time and compared. The AGS property displayed a larger impact on vertebral axial displacement and von Mises stress in AGS, and the AF property displayed a larger impact on disc bulge. In contrast, the NP property had little effect on all the response parameters. Additionally, the intradiscal pressure was found to be not sensitive to any of the disc properties. These findings may be helpful in adoption of appropriate material parameters for the intervertebral disc in finite element model of the lumbar spine used for vibration analysis. Graphical abstract Material property sensitivity analysis on vibration characteristics of the human lumbar spine.

Effects of pulse ultrasound and kneading massage in managing individual with incessant pain at lower region of back using random allocation

The study examined the effect of pulsed therapeutic ultrasound in management of patients with incessant pain at lower region of the back (PWIPLB) in comparison with kneading massage (KM). Fifty PWIPLB recruited purposively were randomly assigned into ultrasound group (USG) and KM group (KMG) equally. Subjects received back extension exercises as baseline treatment. USG received pulse ultrasound (PUS) while KMG was treated using KM. The treatments were administered 2 times weekly for a 6-week period. Severity of pain (SP) and inability of patient (IoP) were evaluated at baseline, 3rd week and 6th week of treatment. Values of the variables obtained were classified and the implications were summarised. A significant change was observed in precompared with posttreatment SP (F=32.6, P=0.000) and IoP (F=2.5, P<0.021) in USG. A significant change was observed in precompared with posttreatment IoP (F=4.1, P<0.05) but not in SP (F=2.9, P<0.086). In the 6th week, there was a significant reduction of SP in the USG relative to SP in the KMG (F=11.98, P=0.000), and there was improvement significantly in the IoP in the KMG relative to that in the USG (F=2.58, P=0.05). PUS may be better than KM in management of SP but KM is better than PUS in IoP with PWCPLB.

LifeChair: A Conductive Fabric Sensor-Based Smart Cushion for Actively Shaping Sitting Posture

The LifeChair is a smart cushion that provides vibrotactile feedback by actively sensing and classifying sitting postures to encourage upright posture and reduce slouching. The key component of the LifeChair is our novel conductive fabric pressure sensing array. Fabric sensors have been explored in the past, but a full sensing solution for embedded real world use has not been proposed. We have designed our system with commercial use in mind, and as a result, it has a high focus on manufacturability, cost-effectiveness and adaptiveness. We demonstrate the performance of our fabric sensing system by installing it into the LifeChair and comparing its posture detection accuracy with our previous study that implemented a conventional flexible printed PCB-sensing system. In this study, it is shown that the LifeChair can detect all 11 postures across 20 participants with an improved average accuracy of 98.1%, and it demonstrates significantly lower variance when interfacing with different users. We also conduct a performance study with 10 participants to evaluate the effectiveness of the LifeChair device in improving upright posture and reducing slouching. Our performance study demonstrates that the LifeChair is effective in encouraging users to sit upright with an increase of 68.1% in time spent seated upright when vibrotactile feedback is activated.

No increase in 6-week treatment effect of Mechanical Diagnosis and Therapy with the use of the LUMOback in people with non-acute non-specific low back pain and a directional preference of extension: a pilot randomized controlled trial

OBJECTIVES

To pilot the methods for a randomized controlled trial (RCT) to investigate whether the treatment effect of Mechanical Diagnosis and Therapy (MDT) is enhanced with the LUMOback.

DESIGN

Assessor blinded RCT with 3 and 6-week follow-ups.

SETTING

An outpatient clinic.

PARTICIPANTS

Primary eligibility criteria were: a directional preference of lumbar extension, ≥18years of age, and non-specific low back pain lasting for ≥1month.

INTERVENTIONS

The MDT group undertook extension exercises (10reps/3hour) and postural correction using a lumbar roll at home. The MDT+LUMOback group also wore the LUMOback daily, providing a vibration alert in a slouched posture.

MAIN OUTCOME MEASURES

The Global Rating of Change Scale (GRCS) (0-6), recruitment rate per month, treatment sessions, compliance rate of wearing the LUMOback, participants' adherence with treatment, dropout rate and the stage of the MDT program at six weeks.

RESULTS

Twenty-two participants were included for 20 months (a recruitment rate of 1.1 patient/month). Dropout rate was 9%. The mean (SD) of the GRCS of the MDT and MDT+LUMOback groups were 4.7 (0.8) and 4.7 (0.5) at the 3-week follow-up and were both 4.9 (0.5) at the 6-week follow-up. The patients undertook a mean of 6.7 sessions for six weeks and exercises with mean of 3.7set/day in each group. The mean compliance rate of wearing the LUMOback was 88%. Nobody was discharged from the intervention with full recovery within six weeks.

CONCLUSIONS

Data indicated a promising method for the full RCT, but a rationale for the full RCT was not justified.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000018380.

Questionnaire on body awareness of postural habits in young people: construction and validation

Abstract Introduction: The postural deviations associated with the changes in the habits of young people have increased over the last decades. Investigating the subject by way of a self-perception questionnaire allows one to understand the level of awareness the individual has concerning his/her postural habits. Objective: Designing a self-perception evaluation questionnaire about the postural habits of young people and to validate, pre-test, verify the reliability and the internal consistency of this instrument. Methods: The validity of the content was determined by 10 judges. The study involved young people (15 - 18 years old) from Florianopolis/Brazil. The questionnaire was pre-tested, applied to 15 youthful who provided qualitative information about it. The reproducibility was analyzed by way of a test-retest with 40 students, in a one-week gap, and was analyzed by interclass correlation coefficient. The internal consistency was analyzed by Cronbach’s alpha with 679 students. A 5% significance level was adopted. Results: Concerning to the validation of content, the questionnaire presented a total coefficient of 0.28 and 72% concordance was observed amongst the reviewers. The interclass correlation coefficient (test-retest) indicated acceptable reproducibility values (R = 0.66, 0.74 and 0.59; p < 0.001), with a decrease in the object-carrying dimension (R = 0.32; p = 0.04). The questionnaire was considered suitable, quick and easy to fill in. The internal consistency presented a value of 0.80. Conclusion: The questionnaire on body awareness of postural habits in young people is a valid instrument with good repeatability and reliability, its use can be recommended with teenagers showing the same profile as those used in this study.

Effect of alternating postures on cognitive performance for healthy people performing sedentary work

Prolonged sitting is a risk factor for several diseases and the prevalence of worksite-based interventions such as sit-to-stand workstations is increasing. Although their impact on sedentary behaviour has been regularly investigated, the effect of working in alternating body postures on cognitive performance is unclear. To address this uncertainty, 45 students participated in a two-arm, randomised controlled cross-over trial under laboratory conditions. Subjects executed validated cognitive tests (working speed, reaction time, concentration performance) either in sitting or alternating working postures on two separate days (ClinicalTrials.gov Identifier: NCT02863731). MANOVA results showed no significant difference in cognitive performance between trials executed in alternating, standing or sitting postures. Perceived workload did not differ between sitting and alternating days. Repeated measures ANOVA revealed significant learning effects regarding concentration performance and working speed for both days. These results suggest that working posture did not affect cognitive performance in the short term. Practitioner Summary: Prior reports indicated health-related benefits based on alternated (sit/stand) body postures. Nevertheless, their effect on cognitive performance is unknown. This randomised controlled trial showed that working in alternating body postures did not influence reaction time, concentration performance, working speed or workload perception in the short term.

A scoping review of biopsychosocial risk factors and co-morbidities for common spinal disorders

OBJECTIVE

The purpose of this review was to identify risk factors, prognostic factors, and comorbidities associated with common spinal disorders.

METHODS

A scoping review of the literature of common spinal disorders was performed through September 2016. To identify search terms, we developed 3 terminology groups for case definitions: 1) spinal pain of unknown origin, 2) spinal syndromes, and 3) spinal pathology. We used a comprehensive strategy to search PubMed for meta-analyses and systematic reviews of case-control studies, cohort studies, and randomized controlled trials for risk and prognostic factors and cross-sectional studies describing associations and comorbidities.

RESULTS

Of 3,453 candidate papers, 145 met study criteria and were included in this review. Risk factors were reported for group 1: non-specific low back pain (smoking, overweight/obesity, negative recovery expectations), non-specific neck pain (high job demands, monotonous work); group 2: degenerative spinal disease (workers' compensation claim, degenerative scoliosis), and group 3: spinal tuberculosis (age, imprisonment, previous history of tuberculosis), spinal cord injury (age, accidental injury), vertebral fracture from osteoporosis (type 1 diabetes, certain medications, smoking), and neural tube defects (folic acid deficit, anti-convulsant medications, chlorine, influenza, maternal obesity). A range of comorbidities was identified for spinal disorders.

CONCLUSION

Many associated factors for common spinal disorders identified in this study are modifiable. The most common spinal disorders are co-morbid with general health conditions, but there is a lack of clarity in the literature differentiating which conditions are merely comorbid versus ones that are risk factors. Modifiable risk factors present opportunities for policy, research, and public health prevention efforts on both the individual patient and community levels. Further research into prevention interventions for spinal disorders is needed to address this gap in the literature.

Inverse Piezoresistive Nanocomposite Sensors for Identifying Human Sitting Posture

Sitting posture is the position in which one holds his/her body upright against gravity while sitting. Poor sitting posture is regarded as an aggravating factor for various diseases. In this paper, we present an inverse piezoresistive nanocomposite sensor, and related deciphering neural network, as a new tool to identify human sitting postures accurately. As a low power consumption device, the proposed tool has simple structure, and is easy to use. The strain gauge is attached to the back of the user to acquire sitting data. A three-layer BP neural network is employed to distinguish normal sitting posture, slight hunchback and severe hunchback according to the acquired data. Experimental results show that our method is both realizable and effective, achieving 98.75% posture identification accuracy. This successful application of inverse piezoresistive nanocomposite sensors reveals that the method could potentially be used for monitoring of diverse physiological parameters in the future.

Improving posture and sitting behavior through tactile and visual feedback in a sedentary environment

This paper presents the concept Backtive: an interactive office chair with an accompanying mobile application to provide both tactile and visual feedback for the user to correct his posture and make him more aware of the sitting behavior throughout the day. The concept aims to make people unintentionally and more voluntarily aware of their sitting behavior while not interrupting their daily tasks. The concept is developed through a user centered design approach and by building a prototype to test feasibility as well as evaluating the concept. An evaluation with four persons received positive results with regard to credibility and expectancy of Backtive for posture improvement. Participants also expect that Backtive would be easy in use and are likely to integrate the system in their daily activities.

The effects of breaks on low back pain, discomfort, and work productivity in office workers: A systematic review of randomized and non-randomized controlled trials

The purpose of this study was to evaluate the effectiveness of breaks on low back pain, discomfort, and work productivity in office workers. Publications were systematically searched in several databases from 1980 to December 2016. Relevant randomized and non-randomized controlled trials were retrieved and assessed for methodological quality by two independent reviewers. Quality of evidence was assessed and rated according to GRADE guidelines. Eight randomized controlled trials and three non-randomized controlled trials were included in this review, of which 10 were rated as high-quality studies. The break programs were highly heterogeneous with work duration ranging from 5 min to 2 h and break duration ranging from 20 s to 30 min. The results showed low-quality evidence for the conflicting effect of breaks on pain and low-quality evidence for the positive effect of breaks on discomfort. When stratified by type of breaks, moderate-quality evidence was found for the positive effect of active breaks with postural change for pain and discomfort. Moderate-quality evidence indicated that the use of breaks had no detrimental effect on work productivity. More high-quality studies are needed before recommendations can be given. Within a number of methodological limitations that are present in the published studies, active breaks with postural change may be effective in reducing pain in workers with acute low back pain and to prevent discomfort in healthy subjects.

Biomechanical investigation of prolonged driving in an ergonomically designed truck seat prototype

A postural evaluation during a prolonged driving task was conducted to determine the ergonomic validity of a new freely adjustable truck seat prototype. Twenty participants were recruited to perform two 2-h simulated driving sessions. Postures were assessed using motion capture, accelerometers and pressure pads. Subjective discomfort was also monitored in 15-min increments using ratings of perceived discomfort (RPD) and the Automotive Seating Discomfort Questionnaire. Participants had a more neutral spine posture during the first hour of the drive and reported lower RPDs while sitting in the prototype. Pairing the gluteal backrest panel with the adjustable seat pan helped reduce the average sitting pressure. The industry-standard truck seat may lead to the development of poor whole body posture, and the proposed ergonomic redesign of a new truck seat helped improve sitting posture and reduce perceived discomfort. Practitioner Summary: A new freely adjustable truck seat prototype was compared to an Industry standard seat to assess hypothesised improvements to sitting posture and discomfort for long haul driving. It was found that the adjustable panels in the prototype helped promote spine posture, reduce sitting pressure and improved discomfort ratings.

Long-term effects of exercise programs among helicopter pilots with flying related LBP

BACKGROUND

Flying related transient Low Back Pain (LBP) among helicopter pilots is considered an occupational distress.

OBJECTIVE

To examine if exercise programs can alleviate transient LBP.

METHODS

Sixty-five helicopter pilots (92% males), all reporting flying related LBP, responded to an epidemiological survey and a long-term follow-up, 44.8 months later, comprising questions regarding transient LBP and number of sick leaves. Data from 37 pilots participating in two exercise programs, A; general for LBP, B; focused for lumbar trunk (LT), included information from clinical examinations and muscular endurance tests of the LT before and after intervention. Twenty-eight pilots did not participate in any intervention.

RESULTS

At long-term follow-up 42% of the pilots still reported flying related transient LBP. Among participants in program B 26% had persistent pain, 70% in program A and 46% among pilots without intervention. Sick-leave reduction was only observed among participants in program B (30% to 4%). Upon re-occurrence of LBP symptoms, half of the pilots in program B again performed exercises to improve their pain.

CONCLUSION

This study indicates that exercise programs focused towards lumbar trunk muscular endurance reduces flying related transient LBP and sick-leave among helicopter pilots. These findings may have implications for the pilots' working conditions.

High prevalence of inadequate sitting and sleeping postures: a three-year prospective study of adolescents

There is a paucity of information regarding the development of body posture during adolescence. This three-year prospective study aimed to evaluate sitting and sleeping postures among adolescents, and to determine whether these postures are associated with age and sex. We assessed 525 adolescents aged 11-16 years from the fifth to eighth grades. These adolescents were reassessed three years later. The Back Pain and Body Posture Evaluation Instrument was used to evaluate the sleeping posture and three sitting positions: sitting to write, to use a computer, and during leisure activities. Our findings indicated a low prevalence of adequate sleeping and sitting postures at baseline, with a decrease in prevalence observed after three years for all postures. These changes were similar for both sexes. Moreover, we found a strong reduction of adequate posture prevalence for younger adolescents, but the oldest adolescents demonstrated no significant differences after three years. Early, rather than late, adolescence is a critical period for establishing inadequate sitting and sleeping postures. This has implications for posture throughout adulthood; hence, interventions targeted at this age group are needed.

Full shift assessment of back and head postures in overhead crane operators with and without symptoms

OBJECTIVES

Prolonged sitting with a flexed back and neck is recognized as being associated with an increased risk of neck and back pain disorders among overhead crane operators. The aim of this study was to compare back and head postures over a full shift of work between operators who experience back and neck pain, and healthy operators.

METHODS

In a first phase, the prevalence of musculoskeletal symptoms was assessed using the Nordic questionnaire among 120 crane operators. Based on first phase results, 17 operators with back/neck disorders were matched with 15 healthy operators based on age and selected to participate in the second phase of the study. Postures and movements were continuously measured over an 8 h shift using inclinometers.

RESULTS

The highest 12-month prevalence of musculoskeletal disorders was found in the lower back, neck and knees. Case and control groups differed significantly in back and head flexion angles at the 50th percentiles APDF (p < 0.05). There was also a significant difference in the time spent working in an extreme posture of the back and head between groups (p < 0.05).

CONCLUSIONS

This is the first study to document work postures assumed during a full work shift and to compare postures between symptomatic and healthy overhead crane operators. Physical exposure in case group operators was characterized by more awkward and extreme postures in the back and head. The results of this study demonstrate that effective prevention strategies directed towards musculoskeletal disorders are required that address awkward work postures for overhead crane operators.

Lumbar spine postures in Marines during simulated operational positions

Low back pain has a 70% higher prevalence in members of the armed forces than in the general population, possibly due to the loads and positions soldiers experience during training and combat. Although the influence of heavy load carriage on standing lumbar spine posture in this population is known, postures in other operationally relevant positions are unknown. Therefore, the purpose of this study was to characterize the effect of simulated military operational positions under relevant loading conditions on global and local lumbar spine postures in active duty male US Marines. Secondary objectives were to evaluate if intervertebral disc degeneration and low back pain affect lumbar spine postures. Magnetic resonance images were acquired on an upright scanner in the following operational positions: Natural standing with no external load, standing with body armor (11.3 kg), sitting with body armor, and prone on elbows with body armor. Custom software was used to measure global lumbar spine posture: Lumbosacral flexion, sacral slope, lordosis, local measures of intervertebral angles, and intervertebral distances. Sitting resulted in decreased lumbar lordosis at all levels of the spine except L1-L2. When subjects were prone on elbows, a significant increase in local lordosis was observed only at L5-S1 compared with all other positions. Marines with disc degeneration (77%) or history of low back pain (72%) had decreased lumbar range of motion and less lumbar extension than healthy Marines. These results indicate that a male Marine's pathology undergoes a stereotypic set of postural changes during functional tasks, which may impair performance. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2145-2153, 2017.

Association Between Whole-Body Vibration and Low-Back Disorders in Farmers: A Scoping Review

INTRODUCTION

Low-back disorders (LBDs) are the most common musculoskeletal problem among farmers, with higher prevalence rates than in other occupations. Farmers who operate tractors and other types of machinery can have substantial exposure to whole-body vibration (WBV). Although there appears to be an association between LBDs and WBV, the causal relationship is not clear.

OBJECTIVE

This scoping review investigates the association between WBV and LBDs specifically among farmers.

METHODS

Nine databases were searched using groups of terms for two concepts: 'farming' and 'low back disorder'. Screening, data extraction, and quality assessment were performed by two reviewers independently. Included studies met the following criteria: focused on adult farmers/agricultural workers; assessed exposure to operating farm machinery such tractor, combine, or all-terrain vehicle; assessed LBDs as an outcome; and reported an inferential test to assess the relationship between WBV and LBD.

RESULTS

After 276 full texts screened, 11 articles were found to analyze WBV as a risk factor for LBDs. Three were case-control, five cross-sectional, and three retrospective cohorts. Four studies showed no association between WBV and LBDs, four a positive association, and three results were mixed depending on the exposure/outcome measure.

CONCLUSION

A firm conclusion is difficult due to heterogeneity in, LBDs definition, type of farm commodity, study design, and statistical strategy. Direct comparisons and synthesis were not possible. Although retrospective cohort studies tended to show a relationship, future studies with a prospective cohort design could help clarify this association further.

Habitual pelvic posture and time spent sitting: Measurement test-retest reliability for the LUMOback device and preliminary evidence for slouched posture in individuals with low back pain

OBJECTIVES

It has been difficult to monitor the pelvic position during actual daily life. However, recent developments in wearable device technologies, such as the LUMOback device, provide the possibility to evaluate habitual pelvic posture and time spent sitting during daily life. The current study aimed (1) to investigate test-retest reliability for habitual pelvic posture and time spent sitting with the LUMOback in individuals with prolonged low back pain (low back pain group) and without low back pain (control group), and (2) to preliminarily investigate differences in those measures between groups.

METHODS

Fifteen individuals in each group wore the LUMOback daily for 2 weeks. Intraclass correlation coefficients were calculated in each group by comparing the mean from the first week with the mean from the second week: (1) for the posture score, which is a proportion of time with neutral posture, and (2) for time spent sitting. The two measures for the first week were compared between the low back pain and control groups.

RESULTS

The intraclass correlation coefficients for the posture score were .82 in the low back pain group and .91 in the control group. The intraclass correlation coefficients for time spent sitting were .75 in the low back pain group and .85 in the control group. The posture score in the low back pain group (mean ± SD: 37.5% ± 10.3%) was less than that in the control group (49.6% ± 6.0%; p < .001), but there was no difference in time spent sitting between the groups (p > .05).

CONCLUSIONS

The current study found (1) acceptable test-retest reliability for the posture score and time spent sitting evaluated by the LUMOback device, and (2) preliminary evidence of a difference in the posture score, indicating a more slouched lumbopelvic posture in individuals with prolonged low back pain than those without low back pain.

Influence of seat tilt motion on discomfort perception during a simulated driving activity

BACKGROUND

Discomfort perceived in activities where there is a prolonged sitting posture are normally compensated in a natural way by means of macro-repositioning movements in the seat. Nevertheless, evidence shows that such movements are not able to palliate discomfort due to lumbar pain.

OBJECTIVE

This study involves research performed to demonstrate whether induced postural changes are able to mitigate this type of discomfort during a simulated driving activity.

METHODS

Twenty-four subjects with lumbar pain (LBP) and without lumbar pain (WLBP) underwent 90 min of simulated driving activities while periodic variations of seat tilt (Tt) were implemented.

RESULTS

Discomfort perception due to lumbar pain significantly decreased in the case of Tt compared with the case of WTt (without seat tilt), and significant differences were found (p = 0.02). However, treatments with Tt indicated that no substantial differences exist between LBP and WLBP subjects when considering discomfort perception due to lumbar pain and the erector spinae activity.

CONCLUSIONS

This study revealed that periodic variations on seat tilt can help to reduce discomfort perception due to lumbar pain during driving activities, regardless of the health condition of the subject.

Workplace interventions to improve sitting posture: A systematic review

PURPOSE

Evaluate the effectiveness of workplace interventions to improve sitting posture of workers that spend long periods of time seated at a visual display terminal.

METHODS

A systematic review of randomised controlled trials, non-randomised controlled trials and single-group intervention trials featuring workplace interventions with pre- and follow-up measurements of sitting posture was conducted (registered in PROSPERO, CRD#42015027648). Nine databases were searched for studies available between January 2005 and February 2016.

RESULTS

2519 articles were screened with 12 studies meeting the inclusion criteria. The included studies featured various ergonomic workplace interventions and comprised 4 randomised controlled trial (n=457), 2 non-randomised controlled trials (n=416) and 6 single-group intervention trials (n=328). Due to clinical and methodological heterogeneity, pooling of data was not completed and a narrative summary of findings was developed using the Grading of Recommendations Assessment Development and Evaluation (GRADE) framework. The evidence for four review outcomes was assessed with medium to large positive improvements obtained for the majority of studies investigating changes to gross sitting posture, whereas mixed findings were obtained for more specific local segment assessments of sitting posture. The overall evidence quality for all review outcomes were identified as either 'low' or 'very low'.

CONCLUSION

There is evidence which is limited in quality to indicate that ergonomic workplace interventions can improve gross sitting posture. More high quality research across a range of intervention types is required with longer follow-up durations and more advanced methods to assess sitting posture with greater frequency and less bias.

Impact of exercise programs among helicopter pilots with transient LBP

Background

Flight related low back pain (LBP) among helicopter pilots is frequent and may influence flight performance. Prolonged confined sitting during flights seems to weaken lumbar trunk (LT) muscles with associated secondary transient pain. Aim of the study was to investigate if structured training could improve muscular function and thus improve LBP related to flying.

Methods

39 helicopter pilots (35 men and 4 women), who reported flying related LBP on at least 1 of 3 missions last month, were allocated to two training programs over a 3-month period. Program A consisted of 10 exercises recommended for general LBP. Program B consisted of 4 exercises designed specifically to improve LT muscular endurance. The pilots were examined before and after the training using questionnaires for pain, function, quality of health and tests of LT muscular endurance as well as ultrasound measurements of the contractility of the lumbar multifidus muscle (LMM).

Results

Approximately half of the participants performed the training per-protocol. Participants in this subset group had comparable baseline characteristics as the total study sample. Pre and post analysis of all pilots included, showed participants had marked improvement in endurance and contractility of the LMM following training. Similarly, participants had improvement in function and quality of health. Participants in program B had significant improvement in pain, function and quality of health.

Conclusions

This study indicates that participants who performed a three months exercise program had improved muscle endurance at the end of the program. The helicopter pilots also experienced improved function and quality of health.

Trial registration

Identifier: NCT01788111 Registration date; February 5th, 2013, verified April 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1631-0) contains supplementary material, which is available to authorized users.

Low back pain among office workers in three Spanish-speaking countries: findings from the CUPID study

OBJECTIVES

To assess the differences in the prevalence and incidence of low back pain (LBP) and associated disability among office workers in Costa Rica, Nicaragua and Spain.

METHODS

Data were collected at baseline (n=947, 93% response) in November 2007 and at follow-up after 12 months (n=853, 90% response). Six outcome measures were examined: baseline prevalence of (1) LBP in the past 12 months, (2) LBP in the past month and (3) disabling LBP in the past month; and at follow-up: (4) incidence of new LBP in the past month, (5) new disabling LBP and (6) persistent LBP. Differences in prevalence by country were characterised by ORs with 95% CIs, before and after adjustment for covariates.

RESULTS

Prevalence of LBP in the past month among office employees in Costa Rica (46.0%) and Nicaragua (44.2%) was higher than in Spain (33.6%). Incidence of new LBP was 37.0% in Nicaragua (OR=2.49; 95% CI 1.57 to 3.95), 14.9% in Costa Rica (OR=0.74; 95% CI 0.41 to 1.34) and 19.0% in Spain (reference). Incidence of new disabling LBP was higher in Nicaragua (17.2%; OR=2.49; 95% CI 1.43 to 4.34) and Costa Rica (13.6%; OR=1.89; 95% CI 1.03 to 3.48) than Spain (7.7%), while persistence of LBP was higher only in Nicaragua.

CONCLUSIONS

Prevalence of LBP and disabling LBP was higher in Costa Rican and Nicaraguan office workers than in Spain, but the incidence was higher mainly in Nicaragua. Measured sociodemographic, job-related and health-related variables only partly explained the differences between countries, and further research is needed to explore reasons for the remaining differences.

Evaluation of factors associated with severe and frequent back pain in high school athletes

Several studies have shown that half of all young athletes experience back pain (BP). However, high intensity and frequency of BP may be harmful, and the factors associated with BP severity have not been investigated in detail. Here, we investigated the factors associated with a high intensity and high frequency of BP in high school athletes. We included 251 athletes (173 boys and 78 girls [14-20 years old]) in this cross-sectional study. The dependent variables were a high frequency and high intensity of BP, and the independent variables were demographic, socioeconomic, psychosocial, hereditary, anthropometric, behavioural, and postural factors and the level of exercise. The effect measure is presented as prevalence ratio (PR) with 95% confidence interval (CI). Of 251 athletes, 104 reported BP; thus, only these athletes were included in the present analysis. Results of multivariable analysis showed an association between high BP intensity and time spent using a computer (PR: 1.15, CI: 1.01-1.33), posture while writing (PR: 1.41, CI: 1.27-1.58), and posture while using a computer (PR: 1.39, CI: 1.26-1.54). Multivariable analysis also revealed an association of high BP frequency with studying in bed (PR: 1.19, CI: 1.01-1.40) and the method of carrying a backpack (PR: 1.19, CI: 1.01-1.40). In conclusion, we found that behavioural and postural factors are associated with a high intensity and frequency of BP. To the best of our knowledge, this study is the first to compare different intensities and frequencies of BP, and our results may help physicians and coaches to better understand BP in high school athletes.

A Survey on Low Back Pain Risk Factors in Steel Industry Workers in 2015

Study Design

This was a cross-sectional study.

Purpose

The aim of this study was to determine the prevalence of low back pain (LBP) and its association with individual factors and current job status among steel industry workers in Mashhad, Iran.

Overview of Literature

Several studies have been conducted on LBP and its related risk factors, some of which emphasized oc-cupational factors as the main etiology of LBP. Meanwhile, individual risk factors have been emphasized in other studies. Despite several published articles, there are still many unresolved, basic issues about developing LBP.

Methods

For this study, 358 male workers were selected by a random sampling method and divided into two groups: production workers (n=201) and administrative personnel (n=157). Data were collected using modified Nordic questionnaire and physical examination. Statistical analysis was performed to identify the correlation between individual factors and current job status with LBP.

Results

Despite the young age of participants and their short employment duration, the overall prevalence of LBP was high (32.4%) in this industry. The prevalence of non-specific LBP in production workers and administrative personnel was 26.8% and 21.0%, respectively. Disk herniation was observed in 10.4% of production workers and 6.3% of administrative personnel. Age, employment duration, body mass index and smoking status were similar in the two groups. There was no significant relationship between LBP and current job status; however, a significant relationship was found between prevalence of LBP with age, duration of employment, and leisure time physical activity (p<0.05).

Conclusions

We have not found any relationship between LBP and current occupational status suggesting that the effects of general health-related factors such as weight, age, leisure time physical activity, and duration of employment are more important than occupational factors in developing LBP.

Seat Pressure Distribution Characteristics During 1 Hour Sitting in Office Workers With and Without Chronic Low Back Pain

Background

Low back pain (LBP) is a major problem for office workers. Individuals adopting poor postures during prolonged sitting have a considerably increased risk of experiencing LBP. This study aimed to investigate seat pressure distribution characteristics, i.e., average pressure, peak pressure ratio, frequency of postural shift, and body perceived discomfort (BPD), during 1 hour of sitting among office workers with and without chronic LBP.

Methods

Forty-six participants (chronic LBP = 23, control = 23) typed a standardized text passage at a computer work station for an hour. A seat pressure mat device was used to collect the seat pressure distribution data. Body discomfort was assessed using the Body Perceived Discomfort scale.

Results

Office workers with chronic LBP sat significantly more asymmetrically than their healthy counterparts. During 1-hour sitting, all workers appeared to assume slumped sitting postures after 20 minutes of sitting. Healthy workers had significantly more frequent postural shifts than chronic LBP workers during prolonged sitting.

Conclusion

Different sitting characteristics between healthy and chronic LBP participants during 1 hour of sitting were found, including symmetry of sitting posture and frequency of postural shift. Further research should examine the roles of these sitting characteristics on the development of LBP.

Back pain prevalence and associated factors in children and adolescents: an epidemiological population study

OBJECTIVE

To identify the prevalence of back pain among Brazilian school children and the factors associated with this pain.

METHODS

All 1,720 schoolchildren from the fifth to the eight grade attending schools from the city of Teutonia, RS, Southern Brazil, were invited to participate in the study. From these, 1,597 children participated. We applied the Back Pain and Body Posture Evaluation Instrument. The dependent variable was back pain, while the independent one were demographic, socioeconomic, behavior and heredity data. The prevalence ratio was estimated by multivariate analysis using the Poisson regression model (α = 0.05).

RESULTS

The prevalence of back pain in the last three months was 55.7% (n = 802). The multivariate analysis showed that back pain is associated with the variables: sex, parents with back pain, weekly frequency of physical activity, daily time spent watching television, studying in bed, sitting posture to write and use the computer, and way of carrying the backpack.

CONCLUSIONS

The prevalence of back pain in schoolchildren is high and it is associated with demographic, behavior and heredity aspects.

Prevalence, risks and severity of musculoskeletal disorder symptoms among administrative employees of a Brazilian company

BACKGROUND

Musculoskeletal disorders (MSD) are common among office workers.

OBJECTIVE

To evaluate the prevalence, risks and symptoms of MSD among office workers of a Brazilian dairy company.

METHODS

Fifty office workers participated in the study. The following evaluations and questionnaires were completed: Rapid Upper Limb Assessment, Strain Index, Muscle Fatigue Assessment, Nordic General Questionnaire, and Oswestry Disability Index.

RESULTS

Seventy-four percent (n = 37) of the participants had MSD symptoms. The back was most commonly affected body part (81% , n = 30), followed by the upper limbs (70% , n = 26). Fifty-three percent of the workers with low back pain had mild to moderate disability, and the risk for the hands, wrists and fingers was moderate. Changes are required to reduce the risk of MSD among the participating office workers.

CONCLUSION

The prevalence of MSD symptoms was high; the back and upper limbs were most commonly affected. Data from the evaluations and questionnaires supplemented each other. The Rapid Upper Limb Assessment and Strain Index were better indicators of risk of MSD symptoms than the Muscle Fatigue Assessment. The participating office workers were exposed to moderate risk of developing MSD due to biomechanical overload and changes are required.

The influence of a dynamic elastic garment on musculoskeletal and respiratory wellness in computer users

BACKGROUND

Evidence is growing that computer users are at increased risk of developing musculoskeletal disorders, particularly those involving the upper extremity, with significant financial cost and lost productivity.

OBJECTIVE

The purpose of this study was to determine the short-term effects of wearing a dynamic elastic garment (Posture Shirt[Formula: see text]; AlignMed, USA) on musculoskeletal wellness and health in the computer workplace.

METHODS

Ninety-six computer users were evaluated. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was completed. A functional assessment of posture, lung function, and grip strength was performed after wearing the Posture Shirt[Formula: see text] for 4 weeks. A training log was kept to track usage of the garment, as well as weekly sensations of fatigue, productivity, and energy level.

RESULTS

After 4 weeks, there was statistically significant improvement in forward shoulder and head posture, thoracic kyphosis, and grip strength. Improvements in spirometry measures did not meet statistical significance. Postural fatigue and muscular fatigue decreased by 21% and 29%, respectively, and energy level and productivity increased by 20% and 13%, respectively.

CONCLUSION

This prospective study demonstrated positive short-term impact of the Posture Shirt[Formula: see text] on both subjective and objective measures of posture, lung function, grip strength, fatigue, and productivity.