Risk factors for the first episode of low back pain in children are infrequently validated across samples and conditions: a systematic review

A randomised controlled trial between hamstring muscle tightness and lumbar lordotic angle

Shortening of the hamstring muscles is a common problem in both symptomatic and asymptomatic individuals. Low back pain and injury caused by postural deficits might be caused by an imbalance of this muscle. The various degrees of hamstring muscle stiffness and its impact on trunk postures are relatively unknown. The goal of this study was to see how different hamstring muscle length (HML) ranges influenced lumbar lordotic angle (LLA). Sixty asymptomatic healthy male and female subjects with a mean age of 40.4±9.2 years and a body mass index of 25.5± 2.2 kg/m2 participated in this study. Subjects were randomly assigned to one of three groups (n=20) with hamstring muscle lengths of 111-120 degrees, 121-130 degrees, or 131-140 degrees, respectively by using a random number generator. The LLA was estimated on a lateral lumbosacral radiograph using the Kinovea application, and hamstring muscle length was measured using the active knee extension test at the university’s rehabilitation centre within a week of subject selection. The Pearson correlation test was used to examine the relationship between LLA and HML, and one-way ANOVA was used to compare the two groups. The correlation coefficients were expressed using 95% confidence intervals. A significant relationship between LLA and HML was observed in 111-120 degrees and 121-130 degrees groups (P<0.05), whereas, the HML >130 degrees group had no influence on LLA (P>0.05). The findings show that hamstring muscle tightness between 111 and 130 degrees has a negative impact on lumbar curvature mechanisms. As a result, hamstring muscle tightness less than 130 degrees should be addressed first in clinical stretching programs for patients. The findings also suggest that instead of focusing on HML, rehabilitation specialists should devote more time to other high-priority interventions, particularly in patients with hamstring muscle lengths greater than 130 degrees.

Exceeding 2-h sedentary time per day is not associated with moderate to severe spinal pain in 11- to 13-year-olds: a cross-sectional analysis

Neck, mid-back and low back pain, collectively known as spinal pain, become more common with increasing age across childhood and adolescence. A common belief among the general community is that sedentary time, including screen time, in adolescents is associated with spinal pain. We aimed to investigate whether exceeding 2-h of sedentary time per day is associated with moderate to severe spinal pain in a sample of Danish adolescents aged 11-13 years. We performed a cross-sectional analysis of the SPACE study baseline data (2010). Adolescents self-reported their spinal pain (outcome) via the Young Spine Questionnaire and duration of engagement in sedentary behaviours (exposure). We provide estimates of associations as odds ratios with 95% confidence intervals, stratified by age and sex. The sample comprised 1,303 adolescents (48.7% female, mean age 12.5 years, range 10.9-14.3 years). Approximately 9 out of 10 adolescents exceeded 2-h sedentary time on weekdays outside of school (88.9%) and weekend days (89.9%). Close to one-quarter, 23.3% (95%CI: 21.0-25.6), of participants experienced moderate to severe spinal pain. We found no association between exceeding 2-h sedentary time per day and experiencing moderate to severe spinal pain; odds ratios ranged from 0.34 (95%CI: 0.04-3.20) to 4.65 (95%CI: 0.26-82.44).Conclusion: We found no association between exceeding 2- or 5-h of sedentary time per day and moderate to severe spinal pain in this sample of 11-13-year-old Danish adolescents. Our cross-sectional analysis does not consider the longitudinal or complex sequences of events necessary to address predictive or causal questions. What is Known: • Up to a third of adolescents experience moderate to severe spinal pain, predisposing them to chronic spinal pain in adulthood. • Frequent and excessive sedentary time is associated with poor overall health in adolescents; there is conflicting evidence to suggest whether it is also related to spinal pain. What is New: • We found no association between sedentary time and moderate to severe spinal pain in 11- to 13-year-old Danes.

Evaluation of the relationship between history of lower back pain and asymmetrical trunk range of motion

BACKGROUND

Low back pain (LBP) is a common complaint and preventive measures should be considered immediately. In addition, asymmetrical trunk motion, which occurs due to repetitive motion upon performing daily activities, may be one of the biomechanical factors to cause LBP.

OBJECTIVE

To investigate the characteristics of asymmetrical trunk motion in women with a history of LBP.

METHODS

Thirty-four women were dichotomously categorized into either the LBP or non-LBP group. Trunk active range of motion (RoM) upon sitting and standing were measured via a three-dimensional motion analysis system. Each RoM and rotation and side-flexion asymmetries were calculated and an unpaired t-tests were used to identify differences between each group.

RESULTS

Trunk rotation asymmetry upon sitting and standing position in LBP group was significantly greater than that in non-LBP group. Furthermore, trunk rotation angle upon sitting in LBP group was significantly larger than that in non-LBP group.

CONCLUSIONS

The limited RoM and asymmetry of trunk rotation may be due to imposed repetitive mechanical stress on habitual excessive motion, including most asymmetrical movements. Our findings indicated that a small trunk rotation angle and asymmetrical trunk rotation may be useful parameters to predict LBP onset or other musculoskeletal conditions of the trunk.

Childhood overweight and obesity and back pain risk: a cohort study of 466 997 children

OBJECTIVES

To assess the association between age, sex, socioeconomic group, weight status and back pain risk in a large general population cohort of children.

DESIGN AND SETTING

A dynamic cohort of children aged 4 years in the Information System for Research in Primary Care (SIDIAP) electronic primary care records data in Catalonia. Multivariable Cox models were fitted to explore the association between back pain and weight status categories according to the WHO 2007 growth reference groups (body mass index for age z-score). Models were adjusted for age, sex, socioeconomic status and nationality.

PARTICIPANTS

Children seen at age 4 years at paediatric primary care clinics between 1 January 2006 and 31 December 2013 and followed up until 31 December 2016 or age 15 years.

OUTCOME MEASURES

Incident back pain registered by paediatricians at primary care using the International Statistical Classification of Diseases and Health Related Problems, 10th Edition code M54.

RESULTS

466 997 children were followed for a median 5.0 years (IQR 5.1). In multivariable models, overweight and obesity increased back pain risk, with adjusted HRs of 1.18 (95% CI 1.09 to 1.27) and 1.34 (95%CI 1.19 to 1.51) for overweight and obesity, respectively. Females were at greater risk of back pain than males with adjusted HR 1.40 (95%CI 1.35 to 1.46). Adjusted HR was 1.43 (95%CI 1.33 to 1.55) for back pain in children from the most deprived socioeconomic groups compared with the least deprived socioeconomic groups.

CONCLUSIONS

Maintaining a healthy weight from an early age may reduce the prevalence of back pain in both children and adults. Overweight female children from deprived socioeconomic groups are at greatest risk of back pain and represent a target population for intervention.

Vitamin D levels in relation to low back pain during adolescence

This study aimed to investigate the association between 25-hydroxyvitamin D (25(OH)D) level and low back pain (LBP) among adolescents while adjusting for potential confounders pertinent to this age group including the weight of school bags, BMI and physical activity. A cross-sectional study was conducted on 760 randomly selected adolescents in middle schools. Data on LBP and the risk factors for LBP were collected from parents by a self-administered questionnaire and from adolescents by face-to-face interview. Blood samples were tested in an accredited laboratory; and 25(OH)D was measured using liquid chromatography-tandem MS. The lifetime prevalence and the 6-month prevalence of LBP were 32·28 (95 % CI 28·97, 35·73) % and 21·26 (95 % CI 18·40, 24·33) %, respectively. There was no difference in the geometric mean of 25(OH)D between those with and without LBP in the past 6 months (28·50 nmol/l and 30·82 nmol/l, respectively; P = 0·122). There was no association between 25(OH)D and LBP in the univariable or multivariable analysis whether 25(OH)D fitted as a continuous or as a categorical variable. We found no association between vitamin D level and LBP in adolescents in an area with high prevalence of vitamin D deficiency. Although it is important to have sufficient vitamin D levels during adolescence for several other health benefits, we concluded that vitamin D is not a major determinant for LBP among adolescents in our setting.

Potential risk factors and triggers for back pain in children and young adults. A scoping review, part I: incident and episodic back pain

Background

The one-month prevalence of back pain in children and adolescents has been reported at 33, 28 and 48% at ages 9, 13 and 15 respectively. There are many suspected risk factors and triggers of back pain in young people.

Objective

The purpose of this scoping review was to identify potential risk factors and potential triggers for back pain in young people. The purpose of part I was to identify potential risk factors for incident and episodic back pain in young people. Part II included all eligible studies with unclear or mixed types of back pain.

Methods

Due to the vast number of studies on "risk factors" for back pain, a two-part scoping review of the literature was chosen as the best way to summarise the evidence. We adhered to the PRISMA-ScR guideline for scoping reviews. General potential risk factors and triggers for back pain in children and young adults (≤ 24 years) were included, incorporating physical, environmental, and/or physiological factors. A search was conducted using PubMed and Cochrane databases from inception to September 2018, limited to the English language. Within part I, and because of their importance, only the results of the studies that investigated risk factors of incident back pain and back pain episodes are presented.

Results

The search identified 7356 articles, of which 91 articles were eligible for this scoping review. The majority of the eligible articles had an unclear definition of back pain (results presented in scoping review part II). There were 7 inception cohort studies included and 1 cohort study that met the criteria for part I. The most consistent risk factors for incident and episodic back pain are female sex and older age.

Conclusion

Due to inconsistent ways of reporting on the type of back pain, no definitive risk factor for back pain has been identified. In general, females often report more symptoms, also for other diseases, and older age is not a useful risk factor as it merely indicates that the onset may not be in childhood. Clearly, the time has come to study the causes of back pain from different angles.

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.

Do schoolbags cause back pain in children and adolescents? A systematic review

OBJECTIVE

To investigate whether characteristics of schoolbag use are risk factors for back pain in children and adolescents.

DATA SOURCES

Electronic searches of MEDLINE, EMBASE and CINAHL databases up to April 2016.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective cohort studies, cross-sectional and randomised controlled trials conducted with children or adolescents. The primary outcome was an episode of back pain and the secondary outcomes were an episode of care seeking and school absence due to back pain. We weighted evidence from longitudinal studies above that from cross-sectional. The risk of bias of the longitudinal studies was assessed by a modified version of the Quality in Prognosis Studies tool.

RESULTS

We included 69 studies (n=72 627), of which five were prospective longitudinal and 64 cross-sectional or retrospective. We found evidence from five prospective studies that schoolbag characteristics such as weight, design and carriage method do not increase the risk of developing back pain in children and adolescents. The included studies were at moderate to high risk of bias. Evidence from cross-sectional studies aligned with that from longitudinal studies (ie, there was no consistent pattern of association between schoolbag use or type and back pain). We were unable to pool results due to different variables and inconsistent results.

SUMMARY/CONCLUSION

There is no convincing evidence that aspects of schoolbag use increase the risk of back pain in children and adolescents.

Are Sleep Problems a Risk Factor for the Onset of Musculoskeletal Pain in Children and Adolescents? A Systematic Review

Study Objectives

Musculoskeletal pain is a major burden on the society. Adults with sleep problems are at higher risk of musculoskeletal pain onset, but there is no evidence for this relationship in children and adolescents. This study aimed to systematically review prospective studies on the risk of musculoskeletal pain onset in children and adolescents with sleep problems.

Methods

Five databases (MEDLINE, PsycINFO, AMED, EMBASE, and HMIC) were systematically searched to identify prospective studies that investigated if children and adolescents (aged 6-19 years) with sleep problems are at higher risk of musculoskeletal pain onset. Included studies were assessed for study quality and a best evidence synthesis was carried out on extracted data.

Results

Thirteen prospective studies were identified. Overall, evidence indicates that sleep problems (quality, quantity, and day time tiredness) are not risk factors for musculoskeletal pain onset. Further analysis on specific body regions shows strong evidence that sleep problems are a risk factor for neck pain onset (only in girls) and that sleep problems are not a risk factor for the onset of widespread pain.

Conclusions

Overall, sleep problems are not a risk factor for musculoskeletal pain onset in children and adolescents. Increased risk was found for some specific body regions and subgroups, but the evidence base was less strong and generally inconsistent. This review found a lack of quality in research methodology compared to research in adults, and further research with improved methodology is required.

Physical activity is prospectively associated with spinal pain in children (CHAMPS Study-DK)

Spinal pain and physical inactivity are critical public health issues. We investigated the prospective associations of physical activity intensity with spinal pain in children. Physical activity was quantified with accelerometry in a cohort of primary school students. Over 19 months, parents of primary school students reported children’s spinal pain status each week via text-messaging (self-reported spinal pain). Spinal pain reports were followed-up by trained clinicians who diagnosed each child’s complaint and classified the pain as non-traumatic or traumatic. Associations were examined with logistic regression modeling using robust standard errors and reported with odds ratios (OR). Children (n = 1205, 53.0% female) with mean ± SD age of 9.4 ± 1.4 years, participated in 75,180 weeks of the study. Nearly one-third (31%) of children reported spinal pain, and 14% were diagnosed with a spinal problem. Moderate intensity physical activity was protectively associated with self-reported [OR(95%CI) = 0.84(0.74, 0.95)], diagnosed [OR(95%CI) = 0.79(0.67, 0.94)] and traumatic [OR(95%CI) = 0.77(0.61, 0.96)] spinal pain. Vigorous intensity physical activity was associated with increased self-reported [OR(95%CI) = 1.13(1.00, 1.27)], diagnosed [OR(95%CI) = 1.25(1.07, 1.45)] and traumatic [OR(95%CI) = 1.28(1.05, 1.57)] spinal pain. The inclusion of age and sex covariates weakened these associations. Physical activity intensity may be a key consideration in the relationship between physical activity behavior and spinal pain in children.

Models of Care for addressing chronic musculoskeletal pain and health in children and adolescents

Chronic musculoskeletal pain among children and adolescents is common and can negatively affect quality of life. It also represents a high burden on the health system. Effective models of care for addressing the prevention and management of pediatric musculoskeletal pain are imperative. This chapter will address the following key questions: (1) Why are pediatric-specific models of pain care needed? (2) What is the burden of chronic musculoskeletal pain among children and adolescents? (3) What are the best practice approaches for early identification and prevention of chronic musculoskeletal pain in children and adolescents? (4) What are the recommended strategies for clinical management of chronic pain, including pharmacological, physical, psychological and complementary, and alternative approaches? (5) What are the most effective strategies for implementing models of pain care across different care settings? (6) What are the research priorities to improve models of care for children and adolescents with chronic musculoskeletal pain?

Restriction in lateral bending range of motion, lumbar lordosis, and hamstring flexibility predicts the development of low back pain: a systematic review of prospective cohort studies

Background

Low back pain (LBP) is an increasingly common condition worldwide with significant costs associated with its management. Identification of musculoskeletal risk factors that can be treated clinically before the development of LBP could reduce costs and improve the quality of life of individuals. Therefore the aim was to systematically review prospective cohort studies investigating lower back and / or lower limb musculoskeletal risk factors in the development of LBP.

Methods

MEDLINE, EMBASE, AMED, CINAHL, SPORTDiscus, and the Cochrane Library were searched from inception to February 2016. No age, gender or occupational restrictions of participants were applied. Articles had to be published in English and have a 12 month follow-up period. Musculoskeletal risk factors were defined as any osseous, ligamentous, or muscular structure that was quantifiably measured at baseline. Studies were excluded if participants were pregnant, diagnosed with cancer, or had previous low back surgery. Two authors independently reviewed and selected relevant articles. Methodological quality was evaluated independently by two reviewers using a generic tool for observational studies.

Results

Twelve articles which evaluated musculoskeletal risk factors for the development of low back pain in 5459 participants were included. Individual meta-analyses were conducted based on risk factors common between studies. Meta-analysis revealed that reduced lateral flexion range of motion (OR = 0.41, 95% CI 0.24-0.73, p = 0.002), limited lumbar lordosis (OR = 0.73, 95% CI 0.55-0.98, p = 0.034), and restricted hamstring range of motion (OR = 0.96, 95% CI 0.94-0.98, p = 0.001) were significantly associated with the development of low back pain. Meta-analyses on lumbar extension range of motion, quadriceps flexibility, fingertip to floor distance, lumbar flexion range of motion, back muscle strength, back muscle endurance, abdominal strength, erector spinae cross sectional area, and quadratus lumborum cross sectional area showed non-significant results.

Conclusion

In summary, we found that a restriction in lateral flexion and hamstring range of motion as well as limited lumbar lordosis were associated with an increased risk of developing LBP. Future research should aim to measure additional lower limb musculoskeletal risk factors, have follow up periods of 6-12 months, adopt a standardised definition of LBP, and only include participants who have no history of LBP.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1534-0) contains supplementary material, which is available to authorized users.

Multivariable modeling of factors associated with spinal pain in young adolescence

PURPOSE

To investigate the factors related to the 1-month period prevalence of low back pain (LBP), neck pain (NP) and thoracic spine pain (TSP) in young adolescents, thereby considering potential correlates from the physical, sociodemographic, lifestyle, psychosocial and comorbid pain domains.

METHODS

In this cross-sectional baseline study, 69 factors potentially associated with spinal pain were assessed among 842 healthy adolescents before pubertal peak growth. With consideration for possible sex differences in associations, multivariable analysis was used to simultaneously evaluate contributions of all variables collected in the five domains.

RESULTS

A significantly higher odds of LBP was shown for having high levels of psychosomatic complaints (odds ratio: 4.4; 95 % confidence interval: 1.6-11.9), a high lumbar lordotic apex, retroversed pelvis, introverted personality, and high levels of negative over positive affect. Associations with a higher prevalence and odds of NP were found for psychosomatic complaints (7.8; 2.5-23.9), TSP in the last month (4.9; 2.2-10.8), backward trunk lean, high levels of negative over positive affect and depressed mood. Having experienced LBP (2.7; 1.3-5.7) or NP (5.5; 2.6-11.8) in the preceding month was associated with a higher odds of TSP, as were low self-esteem, excessive physical activity, sedentarism and not achieving the Fit-norm.

CONCLUSIONS

Psychosomatic symptoms and pain comorbidities had the strongest association with 1-month period prevalence of spinal pain in young adolescents, followed by factors from the physical and psychosocial domains. The role that "physical factors" play in non-adult spinal pain may have been underestimated by previous studies.

Approach to the pediatric athlete with back pain: more than just the pars

Back pain in a pediatric patient can present a worrisome and challenging diagnostic dilemma for any physician. Although most back pain can be attributed to muscle strains and poor mechanics, it is necessary to appreciate the full differential of etiologies causing back pain in the pediatric population. The physician must recognize areas of mechanical weakness in the skeletally immature spine and the sport specific forces that can predispose a patient to injury. A comprehensive history involves determining the onset, chronicity, and location of the pain. A focused physical exam includes a neurological exam as well as provocative testing. The combination of a thorough history and focused physical exam should guide appropriate imaging. Radiographic tests are instrumental in narrowing the differential, making a diagnosis, and uncovering associated pathology. Treatment modalities such as activity modification, heat/cold compresses, and NSAIDs can provide pain relief and allow for effective physical therapy. In most cases nonoperative methods are successful in providing a safe and quick return to activities. Failure of conservative measures requires referral to an orthopedic surgeon, as surgical intervention may be warranted.

Pain characteristics of adolescent spinal pain

BACKGROUND

Although adolescent spinal pain increases the risk for chronic back pain in adulthood, most adolescents can be regarded as healthy. The aim of the present study was to provide data on localization, intensity and frequency of adolescent spinal pain and to investigate which physical and psycho-social parameters predict these pain characteristics.

METHOD

On the occasion of Spine Day, an annual event where children and adolescents are examined by chiropractors on a voluntary basis for back problems, 412 adolescents (10 to 16 years) were tested (by questionnaire and physical examination). Pain characteristics (localization, intensity, and frequency) were identified and evaluated using descriptive statistics. Regression analyses were performed to investigate possible influencing psycho-social and physical influence factors.

RESULTS

Adolescents who suffered from pain in more than one spinal area reported higher pain intensity and frequency than those with pain in only one spinal area. Sleep disorders were a significant predictor for pain in more than one spinal area (p < 0.01) as well as a trend for frequent pain (p = 0.06). Adolescents with frequent pain showed impaired balance on one leg standing with closed eyes (p = 0.02).

CONCLUSIONS

Studies on adolescent spinal pain should report data on pain frequency, intensity and localization. Adolescents who present with pain in more than one spinal area or report frequent pain should be followed carefully. Reduced balance with visual deprivation might be a physical indicator of a serious back problem.

Daily exercises and education for preventing low back pain in children: cluster randomized controlled trial

BACKGROUND

Children report low back pain (LBP) as young as 8 years. Preventing LBP in children may prevent or delay adult incidence.

OBJECTIVES

The purpose of this study was to determine whether education and daily exercise affect LBP episodes in children compared with education alone.

DESIGN

This was a prospective, multicenter cluster randomized controlled trial.

SETTING

The study was conducted at 7 New Zealand primary schools.

PARTICIPANTS

Children (n=708), aged 8 to 11 years, from 7 schools stratified by sample size (36, 114, 151, 168, 113, 45, 83) were randomized and allocated to 2 masked groups: intervention (4 schools, n=469) or control (3 schools, n=239).

INTERVENTIONS

Participants in the intervention group were taught 4 spinal movements for daily practice. Both groups participated in education that emphasized "back awareness."

MEASUREMENTS

Low back pain history at baseline was assessed. Children reported episodes of LBP during the previous week on trial days 7, 21, 49, 105, 161, and 270. Analysis was at the individual participant level, with adjustment for school clusters.

RESULTS

There were no significant differences between groups in the odds of reporting no LBP in the previous week during the study period (odds ratio [OR]=0.72; 95% confidence interval [95% CI]=0.46, 1.14; P=.16). The intervention group reported significantly fewer episodes of LBP (OR=0.54; 95% CI=0.39, 0.74; P<.001) and significantly fewer lifetime first episodes of LBP (n=86 [34%]) compared with the control group (n=58 [47%]) (OR=0.60; 95% CI=0.39, 0.91; P=.02). The odds of an episode of LBP were greater in participants with a history of LBP (OR=4.21; 95% CI=3.07, 5.78; P<.001). Low back pain episodes decreased across the trial period for both groups (OR=0.89; 95% CI=0.84, 0.95; P<.001). Adherence to exercise was poor.

LIMITATIONS

Replication in other settings is needed.

CONCLUSIONS

Regular exercise and education appear to reduce LBP episodes in children aged 8 to 11 years compared with education alone.

Low-back pain

Low-back pain is one of the most common painful conditions experienced by humans throughout their life. Some occupational risk factors (namely, heavy manual material handling) may also contribute to the development of low-back pain: due to the high prevalence of both low-back pain and manual material handling in the adult working population, it has been estimated that low-back pain is probably the most common occupational disorder worldwide. Lifetime prevalence of low-back pain has been reported to be as high as 84%, depending on the case definition used, and no age group is spared, even children. Although low-back pain is not a lethal condition, it was estimated at the third rank among all diseases by disability-adjusted life-years in 2010 in the USA, after ischemic heart disease and chronic obstructive pulmonary disease, and at the first rank by years lived with disability. It also ranked high (13th) globally for the same year, in disability-adjusted life-years. Low-back pain is currently classified as nonspecific/specific as to putative cause and as acute (lasting less than 6 weeks), subacute (6-12 weeks), or chronic (more than 12 weeks) according to duration of symptoms. The distinction between nonspecific/specific and acute/subacute/chronic low-back pain is useful not only for epidemiologic studies, but also (mainly) for choosing the appropriate strategy for the diagnosis and treatment of the disorder. Workplace risk factors for low-back pain include manual lifting and whole-body vibration exposure. This chapter will provide an overview of modern concepts of low-back pain (in general) and will then outline some distinctive features of work-related low-back pain.

Incidence and risk factors for first-time incident low back pain: a systematic review and meta-analysis

BACKGROUND CONTEXT

Great effort has been made toward limiting low back pain (LBP). Recent focus has included factors involved with secondary and tertiary prevention, with less attention given to primary prevention.

PURPOSE

This review provided a current estimate of the incidence of LBP and risk factors associated with either first-time LBP or transition to LBP from a baseline of a pain-free state.

STUDY DESIGN

A systematic review and meta-analyses were performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

PATIENT SAMPLE

Studies included subjects aged 18 years or older, from longitudinal, observational, cohort designs that included baseline risk factors to an outcome of either first-time LBP or transition to LBP from a baseline of a pain-free state.

OUTCOME MEASURES

Risk factors and incidence rates were reported using descriptive analysis and the PRISMA guidelines.

METHODS

Electronic search strategies in PubMed, CINAHL/SPORTDiscus, and Cochrane Central Register of Controlled Trials were combined with a hand search to identify articles for inclusion. Studies were classified based on the population studied (community vs. occupational based) and type of LBP outcome (first ever vs. transition from a baseline pain-free state).

RESULTS

A total of 41 studies were included for review. Meta-analytical incidence rates for first-time LBP and transition to pain from a pain-free state were similar (∼25%), regardless of community or occupational populations. Risk factors for first-time LBP or transition to LBP from a baseline of a pain-free state were psychosocial and physically related. No consistent risk factor emerged as predictive of first-time LBP, although prior LBP was a consistent predictor of future incident LBP. Significant heterogeneity was found across studies in most models, which limits these findings.

CONCLUSIONS

The results of this study suggest that incidence of LBP is similar in community and occupational settings regardless of LBP definition. There were multiple diverse physical and psychosocial risk factors for first-time LBP. A history of LBP was the most consistent risk factor for transition to LBP from a baseline of a pain-free state.

The relationship of lumbar multifidus muscle morphology to previous, current, and future low back pain: a 9-year population-based prospective cohort study

STUDY DESIGN

Population based prospective cohort study.

OBJECTIVE

We explored the cross-sectional relationships between lumbar multifidus (LM) intramuscular adipose tissue (IMAT) infiltration and low back pain (LBP) at 3 successive time points and investigated the role of IMAT in predicting the occurrence of LBP after 5 and 9 years.

SUMMARY OF BACKGROUND DATA

Although LBP is a major source of disease burden, the biological determinants of LBP are poorly understood.

METHODS

Participants were 40-year-old adults randomly sampled from a Danish population and followed up at 45 and 49 years of age. At each time point, participants underwent magnetic resonance imaging and reported ever having had LBP, LBP in the previous year, nontrivial LBP in the previous year, or a history of pain radiating into the legs. Pixel intensity and frequencies from T1-weighted magnetic resonance images identified the greatest proportion of LM IMAT at the L4 and L5 spinal levels. IMAT infiltration was categorized as normal/mild, moderate, or severe based on tertile divisions. Associations were explored with crude and adjusted odds ratios (aORs) from logistic regression models. Model covariates included sex, body mass index, and occupational and leisure time physical activity.

RESULTS

A total of 401 participants were enrolled, with 331 (83%) and 286 (71%) participants followed up at 5 and 9 years, respectively. The cross-sectional analyses demonstrated that at the age of 40 years, participants with severe IMAT infiltration demonstrated increased odds of ever experiencing LBP (aOR [95% confidence interval, 95% CI] = 3.16 [1.45-6.89]), nontrivial LBP (aOR [95% CI] = 2.82 [1.36-5.81]), LBP in the past year (aOR [95% CI] = 1.95 [1.07-3.53]), and leg pain (aOR [95% CI] = 2.08 [1.19-3.62]). There were no consistent cross-sectional associations between LBP/leg pain and LM IMAT at 45 or 49 years of age and LM IMAT did not predict future LBP or leg pain.

CONCLUSION

The relationship between LM IMAT and LBP/leg pain is inconsistent and may be modified by age.

LEVEL OF EVIDENCE

N/A.

Low back pain across the life course

Back pain episodes are traditionally regarded as individual events, but this model is currently being challenged in favour of treating back pain as a long-term or lifelong condition. Back pain can be present throughout life, from childhood to older age, and evidence is mounting that pain experience is maintained over long periods: for example, people with pain continue to have it on and off for years, and people without pain do not suddenly develop long-term pain. A number of factors predict back pain presence in epidemiological studies, and these are often present, and predictive, at different life stages. There are also factors present at particular life stages, such as childhood or adolescence, which predict back pain in adulthood. However, there are little published data on long-term pain patterns or predictors over the life course. Such studies could improve our understanding of the development and fluctuations in back pain, and therefore influence treatment approaches.

Spine Day 2012: spinal pain in Swiss school children- epidemiology and risk factors

Background

The key to a better understanding of the immense problem of spinal pain seems to be to investigate its development in adolescents. Based on the data of Spine Day 2012 (an annual action day where Swiss school children were examined by chiropractors on a voluntary basis for back problems), the aim of the present study was to gain systematic epidemiologic data on adolescent spinal pain in Switzerland and to explore risk factors per gender and per spinal area.

Method

Data (questionnaires and physical examinations) of 836 school children were descriptively analyzed for prevalence, recurrence and severity of spinal pain. Of those, 434 data sets were included in risk factor analysis. Using logistic regression analysis, psycho-social parameters (presence of parental back pain, parental smoking, media consumption, type of school bag) and physical parameters (trunk symmetry, posture, mobility, coordination, BMI) were analyzed per gender and per spinal area.

Results

Prevalence of spinal pain was higher for female gender in all areas apart from the neck. With age, a steep increase in prevalence was observed for low back pain (LBP) and for multiple pain sites. The increasing impact of spinal pain on quality of life with age was reflected in an increase in recurrence, but not in severity of spinal pain. Besides age and gender, parental back pain (Odds ratio (OR)=3.26, p=0.011) and trunk asymmetry (OR=3.36, p=0.027) emerged as risk factors for spinal pain in girls. Parental smoking seemed to increase the risk for both genders (boys: OR=2.39, p=0.020; girls: OR=2.19, p=0.051). Risk factor analysis per spinal area resulted in trunk asymmetry as risk factor for LBP (OR=3.15, p=0.015), while parental smoking increased the risk for thoracic spinal pain (TSP) (OR=2.83, p=0.036) and neck pain (OR=2.23, p=0.038). The risk for TSP was further enhanced by a higher BMI (OR=1.15, p=0.027).

Conclusion

This study supports the view of adolescent spinal pain as a bio-psycho-social problem that should be investigated per spinal area, age and gender. The role of trunk asymmetry and passive smoking as risk factors as well as the association between BMI and TSP should be further investigated, preferably in prospective studies.

Postural compensations and subjective complaints due to backpack loads and wear time in schoolchildren

PURPOSE

This study investigated the effects of carrying weighted backpacks of up to 20% of body weight on the posture and pain complaints of elementary-school children.

METHODS

Craniovertebral, forward trunk lean and pelvic tilt angles were measured from sagittal photographs of 62 children (8-11 years old) before and after walking while carrying backpacks containing 10%, 15%, or 20% of body weight. Pain severity after a 6-minute walk with the loaded backpack was recorded. Subjective complaints of pain were assessed using a visual analog scale after walking.

RESULTS

Repeated-measures ANOVA revealed statistically significant differences in postural angles and increased complaints of pain after walking with increased backpack loads.

CONCLUSION

These results indicate that typical backpack loads create worsening postural changes due to backpack loads and time spent carrying those loads, putting children at increased risk for injury and pain, the latter of which is a strong predictor for back pain in adulthood.