Reliability of sagittal photographic spinal posture assessment in adolescents

Effects of Using a Shoulder/Scapular Brace on the Posture and Muscle Activity of Healthy University Students during Prolonged Typing-A Randomized Controlled Cross-Over Trial

Laptop use appears to contribute to poor working postures and neck pain among university students. Postural braces have the potential to improve upper back/neck posture and therefore might have a role as an ergonomic aid for this population. Therefore, the purpose of this study was to assess the short-term effects of scapular bracing on pain, fatigue, cervicothoracic posture, and the activity of the neck and upper-back muscles in healthy college students. A randomized controlled crossover trial was conducted to evaluate the self-reported pain and fatigue, the amplitude and median frequency of surface electromyography in neck extensors, upper trapezius, and lower trapezius, as well as the neck and shoulder sagittal alignment (measured by inertial sensors and digital photographs) during a 30-min typing task in a sample of young, healthy university students with or without a scapular brace. The brace condition resulted in significantly smaller levels of bilateral trapezius muscle activity (p < 0.01). Rounded shoulder posture was slightly better in the brace condition, but these differences were not significant (p > 0.05). There were no significant immediate differences in pain or fatigue scores, neck alignment, or the electromyographic activity of the other muscles tested between brace and non-brace conditions (all p > 0.05). However, bracing appears to immediately reduce the electromyographic activity of the lower trapezius muscles (p < 0.05). These findings shed some light on the possible advantages of scapular bracing for enhancing laptop ergonomics in this group of individuals. Future studies are warranted to evaluate the effects of different types of braces, the importance of matching the brace to the user, and the short- and long-term effects of brace use on computer posture and muscle activity.

Effect of a Posture-Cueing Shirt on Sitting Posture During a Functional Task in Healthy Participants: A Randomized Cross-Over Study

OBJECTIVES

The purpose of this study was to investigate the effect of a posture-cueing shirt on sitting posture during a functional task.

METHODS

Thirty healthy male participants were seated at a standardized workstation while completing 3 laptop writing tasks of 15-minute duration wearing either a posture-cueing shirt, a compression shirt, or no shirt. Posture was assessed based on photos taken at minutes 1 and 15 into the writing task from which the head and shoulder angles were measured and extracted for analysis. After each task, participants rated any potential pain they felt during the task on an 11-point numeric rating scale (NRS).

RESULTS

The results showed that none of the shirts significantly affected the head or shoulder angles at any time point. Participants reported lower pain levels after using the posture-cueing shirt (NRS 0 [0-1]) compared with no shirt (NRS 1 [0-2]; P = .012). No significant difference in pain levels was observed between shirts.

CONCLUSION

Although posture did not change in any conditions for these healthy male subjects, the posture-cueing shirt resulted in a lower pain intensity compared with no shirt but not with a compression shirt. Although a significant difference was found for pain intensity favoring the posture-cueing shirt, this difference was negligible, and thus its value to reduce pain or improve posture in healthy subjects remains in question.

Analysis of the Active Measurement Systems of the Thoracic Range of Movements of the Spine: A Systematic Review and a Meta-Analysis

(1) Objective: to analyze current active noninvasive measurement systems of the thoracic range of movements of the spine. (2) Methods: A systematic review and meta-analysis were performed that included observational or clinical trial studies published in English or Spanish, whose subjects were healthy human males or females ≥18 years of age with reported measurements of thoracic range of motion measured with an active system in either flexion, extension, lateral bending, or axial rotation. All studies that passed the screening had a low risk of bias and good methodological results, according to the PEDro and MINORS scales. The mean values and 95% confidence interval of the reported measures were calculated for different types of device groups. To calculate the differences between the type of device measures, studies were pooled for different types of device groups using Review Manager software. (3) Results: 48 studies were included in the review; all had scores higher than 7.5 over 10 on the PEDro and MINORs methodological rating scales, collecting a total of 2365 healthy subjects, 1053 males and 1312 females; they were 39.24 ± 20.64 years old and had 24.44 ± 3.81 kg/m2 body mass indexes on average. We summarized and analyzed a total of 11,892 measurements: 1298 of flexoextension, 1394 of flexion, 1021 of extension, 491 of side-to-side lateral flexion, 637 of right lateral flexion, 607 of left lateral flexion, 2170 of side-to-side rotation, 2152 of right rotation and 2122 of left rotation. (4) Conclusions: All collected and analyzed measurements of physiological movements of the dorsal spine had very disparate results from each other, the cause of the reason for such analysis is that the measurement protocols of the different types of measurement tools used in these measurements are different and cause measurement biases. To solve this, it is proposed to establish a standardized measurement protocol for all tools.

Quality and usability of clinical assessments of static standing and sitting posture: A systematic review

BACKGROUND

A validated method to assess sitting and standing posture in a clinical setting is needed to guide diagnosis, treatment and evaluation of these postures. At present, no systematic overview of assessment methods, their clinimetric properties, and usability is available.

OBJECTIVE

The objective of this study was to provide such an overview and to interpret the results for clinical practice.

METHODS

A systematic literature review was performed according to international guidelines. Two independent reviewers assessed risk of bias, clinimetric values of the assessment methods, and their usability. Quality of evidence and strength of recommendations were determined according to the Grading of Recommendations Assessment, Development and Evaluation working group (GRADE).

RESULTS

Out of 27,680 records, 41 eligible studies were included. Thirty-two assessment instruments were identified, clustered into five categories. The methodological quality of 27 (66%) of the articles was moderate to good. Reliability was most frequently studied. Little information was found about validity and none about responsiveness.

CONCLUSIONS

Based on a moderate level of evidence, a tentative recommendation can be made to use a direct visual observation method with global posture recorded by a trained observer applying a rating scale.

Reliability of “MB-Ruler Software” to Measure Craniovertebral Angle Using the Photographic Method

Background The craniovertebral angle (CV angle) measurement is a convenient and easy clinical method for the cervical posture assessment. “Markus Bader (MB) ruler software” assists to measure angles and distances on the computer screen. The MB-ruler protractor is almost transparent; hence, it can be easily used on the computer screen. Many studies in physiotherapy have used this software for postural assessment with the photographic method, but the reliability of this software is not available to our knowledge in the Indian population.

Aim The aim of this study was to find inter-rater and intra-rater reliabilities of “MB-Ruler software”, by using the photographic method to measure the CV angle for the cervical postural assessment.

Study Design This is an observational study in healthy young population.

Subjects and Method Total 30 young student volunteers with no clinical symptoms were enrolled for this study. A single standard lateral view image in a sitting position was used for CV angle measurement with “MB ruler software.” Three readings of the CV angle were taken by three different observers (A, B, and C) separately at intervals of time. The CV angle measured by three observers was compared.

Results Cronbach's ɑ coefficient value for intra-rater (ICC 0.999) (intra-class correlation coefficient) as well as inter-rater (ICC 0.892) reliability for measuring CV angle was very high.

Conclusion MB ruler demonstrates high intra-rater and inter-rater reliabilities and can be used for the photographic evaluation of posture by assessing the CV angle.

Role of physical fitness and functional movement in the body posture of children with overweight/obesity

BACKGROUND

Childhood obesity is known to negatively impact body posture with severe consequences for the musculoskeletal system. Physical performance could play a positive role in the body posture conformation of these children, but there is little evidence to date.

RESEARCH QUESTION

Is physical performance (i.e., physical fitness and functional movement) associated with a better body posture in children with overweight/obesity (OW/OB)? If so, is physical performance more determinant than their obesity degree in the body posture conformation?

METHOD

A total of 62 children with OW/OB (10.86 ± 1.25 years, 58 % girls) were included. BMI, physical fitness components (one-repetition-maximum (1RM) arms and leg press, and ALPHA test battery), functional movement quality (Functional Movement Screen™) and body posture (two-dimensional photogrammetry) were evaluated.

RESULTS

Physical fitness components and functional movement were overall associated with a more aligned posture of the head, lumbar and thoracic spines and lower limb. BMI was associated with head protraction, thoracic hyperkyphosis, lumbar hyperlordosis and lower limb valgus. BMI was the best predictor of head and lumbar spine posture, cardiorespiratory fitness of lower limb posture in frontal plane, speed-agility of lower limb posture in the sagittal plane and functional movement of thoracic spine.

SIGNIFICANCE

Our findings reveal that physical fitness and functional movement are associated with a better global body posture in children with OW/OB, and that in some musculoskeletal structures are even better predictors than their obesity degree.

Sagittal standing posture and relationships with anthropometrics and body composition during childhood

BACKGROUND

Anthropometry and body composition are plausible influences on pediatric sagittal standing posture. Despite that, the relationship of anthropometrics since birth and body composition with individual postural parameters in children has never been assessed.

RESEARCH QUESTION

To assess the associations between anthropometrics since birth and body composition parameters, and angles of sagittal standing posture in children.

METHODS

The sample included 1021 girls and 1096 boys, evaluated in the population-based birth cohort Generation XXI, Portugal. Weight and height were obtained at birth, 4 and 7 years of age. At age 7, total body less head fat/fat-free mass and bone properties were estimated from whole body dual energy X-ray absorptiometry scans and posture was assessed through right-side photographs during habitual standing with retro-reflective markers placed on body landmarks.

RESULTS

Girls showed increased values of lumbar angle, head and neck flexion, and craniocervical angle with the largest mean (standard deviation) difference in lumbar angle [281.7° (7.4) vs. 276.8° (7.1) in boys, p < 0.001]. In both genders, weight and body mass index were weakly associated with lumbar angle: 0.24 ≥ r ≤ 0.31 in girls and 0.16 ≥ r ≤ 0.26 in boys, all p < 0.001. Fat and fat-free mass and bone mineral density were weakly associated with lumbar angle in both genders.

SIGNIFICANCE

Our study showed clear postural heterogeneity between girls and boys in early ages. Lumbar angle is likely to be the single most relevant proxy of overall posture based on the associations with the exposures reported in this study.

Current evidence for spinal X-ray use in the chiropractic profession: a narrative review

The use of routine spinal X-rays within chiropractic has a contentious history. Elements of the profession advocate for the need for routine spinal X-rays to improve patient management, whereas other chiropractors advocate using spinal X-rays only when endorsed by current imaging guidelines. This review aims to summarise the current evidence for the use of spinal X-ray in chiropractic practice, with consideration of the related risks and benefits. Current evidence supports the use of spinal X-rays only in the diagnosis of trauma and spondyloarthropathy, and in the assessment of progressive spinal structural deformities such as adolescent idiopathic scoliosis. MRI is indicated to diagnose serious pathology such as cancer or infection, and to assess the need for surgical management in radiculopathy and spinal stenosis. Strong evidence demonstrates risks of imaging such as excessive radiation exposure, overdiagnosis, subsequent low-value investigation and treatment procedures, and increased costs. In most cases the potential benefits from routine imaging, including spinal X-rays, do not outweigh the potential harms. The use of spinal X-rays should not be routinely performed in chiropractic practice, and should be guided by clinical guidelines and clinician judgement.

Two-dimensional digital photography for child body posture evaluation: standardized technique, reliable parameters and normative data for age 7-10 years

BACKGROUND

Digital photogrammetry provides measurements of body angles or distances which allow for quantitative posture assessment with or without the use of external markers. It is becoming an increasingly popular tool for the assessment of the musculoskeletal system. The aim of this paper is to present a structured method for the analysis of posture and its changes using a standardized digital photography technique.

MATERIAL AND METHODS

The purpose of the study was twofold. The first one comprised 91 children (44 girls and 47 boys) aged 7-10 (8.2 ± 1.0), i.e., students of primary school, and its aim was to develop the photographic method, choose the quantitative parameters, and determine the intraobserver reliability (repeatability) along with the interobserver reliability (reproducibility) measurements in sagittal plane using digital photography, as well as to compare the Rippstein plurimeter and digital photography measurements. The second one involved 7782 children (3804 girls, 3978 boys) aged 7-10 (8.4 ± 0.5), who underwent digital photography postural screening. The methods consisted in measuring and calculating selected parameters, establishing the normal ranges of photographic parameters, presenting percentile charts, as well as noticing common pitfalls and possible sources of errors in digital photography.

RESULTS

A standardized procedure for the photographic evaluation of child body posture was presented. The photographic measurements revealed very good intra- and inter-rater reliability regarding the five sagittal parameters and good reliability performed against Rippstein plurimeter measurements. The parameters displayed insignificant variability over time. Normative data were calculated based on photographic assessment, while the percentile charts were provided to serve as reference values. The technical errors observed during photogrammetry are carefully discussed in this article.

CONCLUSIONS

Technical developments are allowed for the regular use of digital photogrammetry in body posture assessment. Specific child positioning (described above) enables us to avoid incidentally modified posture. Image registration is simple, quick, harmless, and cost-effective. The semi-automatic image analysis, together with the normal values and percentile charts, makes the technique reliable in terms of child's posture documentation and corrective therapy effects' monitoring.

A shared biomechanical environment for bone and posture development in children

BACKGROUND CONTEXT

In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children.

PURPOSE

This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns.

STUDY DESIGN

Cross-sectional evaluation.

PATIENT SAMPLE

This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005-2006) and recruited in Porto, Portugal.

OUTCOME MEASURES

Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus.

METHODS

Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions.

RESULTS

The identified patterns were labeled as Sway, Flat, and "Neutral to Hyperlordotic" (in girls), and "Sway to Neutral," Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from -0.86 kg/m² to 0.60 kg/m² in girls and from -0.70 kg/m² to 0.62 kg/m² in boys (vs. Sway or "Sway to Neutral"). Fat and fat-free mass were inversely associated with a Flat pattern and positively associated with a rounded posture: odds ratio (OR) of 0.23 per standard deviation (SD) fat and 0.70 per SD fat-free mass for the Flat pattern, and 1.85 (fat) and 1.43 (fat-free) for the Hyperlordotic pattern in boys, with similar findings in girls. The same direction of relationships was observed between bone physical properties and postural patterns. A positive association between bone (especially bone mineral density) and a rounded posture was robust to adjustment for age, height, and body composition (girls: OR=1.79, p=.006 fat-adjusted, OR=2.00, p=.014 fat-free mass adjusted; boys: OR=2.02, p=.002 fat-adjusted, OR=2.42, p<.001 fat-free mass adjusted).

CONCLUSIONS

In this population-based pediatric setting, there was an inverse association between bone physical properties and a Flat posture. Bone and posture were more strongly positively linked in a rounded posture. Our results support that both bone properties and posture mature in a shared and interrelated mechanical environment, probably modulated by pattern-specific anthropometrics and body composition.

Low Back Pain With Impact at 17 Years of Age Is Predicted by Early Adolescent Risk Factors From Multiple Domains: Analysis of the Western Australian Pregnancy Cohort (Raine) Study

Study Design Prospective cohort study of the Western Australian Pregnancy Cohort (Raine) Study. Background Low back pain (LBP) commonly develops in adolescence and is a significant risk factor for adult LBP. A broad range of factors have been associated with the development of adolescent LBP, but prior literature has limitations related to characterization of LBP and the scope of risk factors considered. Objective This study aimed to identify potential factors contributing to the development of LBP, with and without impact, at 17 years of age, utilizing a broad range of exposures at 14 years of age. Methods Data from 1088 participants (52.1% female) with "no LBP," "LBP with minimal impact," and "LBP with impact" at 17 years of age and a range of measures from multiple domains, including spinal pain, physical, psychological, social, and lifestyle, at 14 years of age were collected for the study. Multivariable multinomial logistic regression was used to estimate the association of potential mechanistic factors at 14 years of age with LBP at 17 years of age. Results Female sex and back pain at 14 years of age were strongly associated with LBP at 17 years of age. Potential mechanistic factors for LBP outcomes at 17 years of age included exposures from the pain (neck/shoulder pain) and physical domains (standing posture subgroup membership, back muscle endurance, throwing distance), psychological domain (somatic complaints, aggressive behavior), social domain (socioeconomic area), and lifestyle domain (exercise out of school). Conclusion The findings support the multidimensional nature of adolescent LBP and highlight the challenge this presents for epidemiological research, clinical practice, and prevention initiatives in the general population. Level of Evidence Prognosis, level 1b. J Orthop Sports Phys Ther 2017;47(10):752-762. doi:10.2519/jospt.2017.7464.

Associations of anthropometry since birth with sagittal posture at age 7 in a prospective birth cohort: the Generation XXI Study

OBJECTIVES

Adult sagittal posture is established during childhood and adolescence. A flattened or hypercurved spine is associated with poorer musculoskeletal health in adulthood. Although anthropometry from birth onwards is expected to be a key influence on sagittal posture design, this has never been assessed during childhood. Our aim was to estimate the association between body size throughout childhood with sagittal postural patterns at age 7.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

A subsample of 1029 girls and 1101 boys taking part in the 7-year-old follow-up of the birth cohort Generation XXI (Porto, Portugal) was included. We assessed the associations between anthropometric measurements (weight, height and body mass index) at birth, 4 and 7 years of age and postural patterns at age 7. Postural patterns were defined using latent profile analysis, a probabilistic model-based technique which allows for simultaneously including anthropometrics as predictors of latent profiles by means of logistic regression.

RESULTS

Postural patterns identified were sway, flat and "neutral to hyperlordotic"in girls, and "sway to neutral", flat and hyperlordotic in boys; with flat and hyperlordotic postures representing a straightened and a rounded spine, respectively. In both girls and boys, higher weight was associated with lower odds of a flat pattern compared with a sway/"sway to neutral"pattern, with stronger associations at older ages: for example, ORs were 0.68 (95% CI 0.53 to 0.88) per SD increase in birth weight and 0.36 (95% CI 0.19 to 0.68) per SD increase in weight at age 7 in girls, with similar findings in boys. Boys with higher ponderal index at birth were more frequently assigned to the hyperlordotic pattern (OR=1.44 per SD; p=0.043).

CONCLUSIONS

Our findings support a prospective sculpting role of body size and therefore of load on musculoskeletal spinopelvic structures, with stronger associations as children get older.

Spinal curvatures of children and adolescents – a cross-sectional study

Study aim: The aim was to assess the spinal curvatures of primary and lower secondary male and female students from Silesia and to identify individual variations that can determine spinal posture.

Material and methods: The study involved 331 girls and 286 boys aged 8 to 16 years. Eligible criteria were non-participation in any professional sport training, and participation in mandatory physical education classes. Posture was evaluated using the moiré method. Measurements of somatic parameters were made with a medical scale using a height meter and a Tanita electronic balance.

Results: Dimorphic postural differences of boys and girls were seen mainly in the shape of lumbar lordosis. Girls were more lordotic than boys at all ages except 10-years-olds. Angle γ was significantly greater in 9-, 15- and 16-year-old girls than boys. LLA was significantly more prominent in 15- and 16-year-old girls than boys. Thoracic kyphosis was significantly more prominent in 8- and 11-year-old boys than girls. We also found a significant effect of age and somatic parameters. In boys mean lumbar lordosis was more pronounced in 10-year-olds. In girls fat mass, fat percentage and BMI correlated with angle α and angle Δ. In boys body height and mass, fat mass, total body water and BMI correlated with angles β, γ, Δ, and lordosis lumbar angle.

Conclusions: The shape of lumbar lordosis is associated with age and gender. Lumbar lordosis decreases with age in male children and adolescents. Our study revealed poor correlations between sagittal spinal curvatures and somatic parameters.

Defining Patterns of Sagittal Standing Posture in Girls and Boys of School Age

Background

Sagittal postural patterns are associated with back pain in adolescents and adults. However, whether postural patterns are already observable during childhood is unknown. Such a finding would confirm childhood as a key period for posture differentiation and thus for chronic pain etiology.

Objective

The aims of this study were to identify and describe postural patterns in girls and boys of school age.

Design

This was a cross-sectional study.

Methods

Eligible children were evaluated at age 7 in the population-based birth cohort Generation XXI in Portugal. Posture was assessed through right-side photographs during habitual standing with retroreflective markers placed on body landmarks. Postural patterns were defined from trunk, lumbar, and sway angles with model-based clusters, and associations with anthropometric measures were assessed by multinomial logistic regression.

Results

Posture was evaluated in 1,147 girls and 1,266 boys. Three postural patterns were identified: sway (26.9%), flat (20.9%), and neutral to hyperlordotic (52.1%) in girls and sway to neutral (58.8%), flat (36.3%), and hyperlordotic (4.9%) in boys. In girls, a higher body mass index was associated with a sway pattern (versus a flat pattern: odds ratio = 1.21; 95% CI = 1.12, 1.29), whereas in boys, a higher body mass index was associated with a hyperlordotic pattern (versus a flat pattern: odds ratio = 1.30; 95% CI = 1.17, 1.44).

Limitations

Photogrammetry as a noninvasive method for posture assessment may have introduced some postural misclassifications.

Conclusions

Postural patterns in 7-year-old children were consistent with those previously found in adults, suggesting that childhood is a sensitive period for posture differentiation. Sagittal morphology differed between girls and boys, emphasizing sex-specific biomechanical loads during a habitual upright position even in prepubertal ages.

Neck Posture Clusters and Their Association With Biopsychosocial Factors and Neck Pain in Australian Adolescents

BACKGROUND

There is conflicting evidence on the association between sagittal neck posture and neck pain.

OBJECTIVE

The purposes of this study were: (1) to determine the existence of clusters of neck posture in a cohort of 17-year-olds and (2) to establish whether identified subgroups were associated with biopsychosocial factors and neck pain.

DESIGN

This was a cross-sectional study.

METHODS

The adolescents (N=1,108) underwent 2-dimensional photographic postural assessment in a sitting position. One distance and 4 angular measurements of the head, neck, and thorax were calculated from photo-reflective markers placed on bony landmarks. Subgroups of sagittal sitting neck posture were determined by cluster analysis. Height and weight were measured, and lifestyle and psychological factors, neck pain, and headache were assessed by questionnaire. The associations among posture subgroups, neck pain, and other factors were evaluated using logistic regression.

RESULTS

Four distinct clusters of sitting neck posture were identified: upright, intermediate, slumped thorax/forward head, and erect thorax/forward head. Significant associations between cluster and sex, weight, and height were found. Participants classified as having slumped thorax/forward head posture were at higher odds of mild, moderate, or severe depression. Participants classified as having upright posture exercised more frequently. There was no significant difference in the odds of neck pain or headache across the clusters.

LIMITATIONS

The results are specific to 17-year-olds and may not be applicable to adults.

CONCLUSION

Meaningful sagittal sitting neck posture clusters were identified in 17-year-olds who demonstrated some differences with biopsychosocial profiling. The finding of no association between cluster membership and neck pain and headaches challenges widely held beliefs about the role of posture in adolescent neck pain.

Reproducibility of the low back clinical postural grouping in adolescents

OBJECTIVE

The purpose of this study was to analyze the intra- and inter-rater reliability of the Low Back Clinical Postural Grouping (LBCPG).

METHODS

Fifty-eight school adolescents were evaluated by lateral photography. The examiners classified the posture of the participants as: hyperlordotic, sway back, flat back or neutral. The intra- and inter-rater reliability were quantified by the percentage agreement between clinicians and the kappa coefficient with 95% confidence intervals (95% CI).

RESULTS

The intra-rater percentage agreement was 91.4%, k = 0.87 (95% IC 0.77-0.98, p < 0.001) for the more experienced rater, and 86.2% k = 0.79 (IC 95% 0.62-0.96, p < 0.001) for the less experienced rater. The percentage agreement between clinicians was 55.17% k = 0.39 (95% CI: 0.23-0.55, p < 0.001). The agreement rose to 70.69%, k = 0.58 (95% CI 0.41-0.74, p < 0.001) when an optional second opinion of the raters was also considered.

CONCLUSION

The LBCPG was reliable when used by the same clinician. The strategy of a second opinion could be used to improve the inter-rater reliability in epidemiological studies with large samples.

Quantitative postural analysis and pain in children and adolescents victims of burns

[Purpose] This study aimed to quantitatively assess postural alignment in both frontal and sagittal planes, as well as pain in children and adolescents victims of burn injuries. [Subjects and Methods] This cross-sectional study included 21 victims of burns, nine children (age [mean ± SD], 7.3 ± 1.1 yrs) and 12 adolescents (12,0 ± 1.4 yrs), classified as medium and large burns, being investigated on pain and postural alignment evaluated by photogrammetry. Pain intensity was assessed by face scales and postural examination included the assessment of global and thoraco-lumbo-pelvic alignment by previously designed protocols. [Results] Only two adolescents reported mild pain associated with burn injuries, whereas deviations of the projection of the gravity center; forward head posture, and scapular asymmetry were observed in both groups. In the analysis of the thoraco-lumbo-pelvic alignment, children tended to have anterior inclination trunk, increased thoracic kyphosis and lumbar lordosis, while in adolescents, increased thoracic kyphosis and lumbar lordosis were observed. [Conclusion] The results indicate that due to the postural alterations and asymmetries in both frontal and sagittal planes, there is an increased risk of developing scoliosis and possible future pain. Thus, physiotherapy is indicated and should be maintained until complete growth is reached.

Photograph-based ergonomic evaluations using the Rapid Office Strain Assessment (ROSA)

The Rapid Office Strain Assessment (ROSA) was developed to assess musculoskeletal disorder (MSD) risk factors for computer workstations. This study examined the validity and reliability of remotely conducted, photo-based assessments using ROSA. Twenty-three office workstations were assessed on-site by an ergonomist, and 5 photos were obtained. Photo-based assessments were conducted by three ergonomists. The sensitivity and specificity of the photo-based assessors' ability to correctly classify workstations was 79% and 55%, respectively. The moderate specificity associated with false positive errors committed by the assessors could lead to unnecessary costs to the employer. Error between on-site and photo-based final scores was a considerable ∼2 points on the 10-point ROSA scale (RMSE = 2.3), with a moderate relationship (ρ = 0.33). Interrater reliability ranged from fairly good to excellent (ICC = 0.667-0.856) and was comparable to previous results. Sources of error include the parallax effect, poor estimations of small joint (e.g. hand/wrist) angles, and boundary errors in postural binning. While this method demonstrated potential validity, further improvements should be made with respect to photo-collection and other protocols for remotely-based ROSA assessments.

Reliability of photographic posture analysis of adolescents

[Purpose] Postural problems of adolescents needs to be evaluated accurately because they may lead to greater problems in the musculoskeletal system as they develop. Although photographic posture analysis has been frequently used, more simple and accessible methods are still needed. The purpose of this study was to investigate the inter- and intra-rater reliability of photographic posture analysis using MB-ruler software. [Subjects and Methods] Subjects were 30 adolescents (15 girls and 15 boys, mean age: 16.4±0.4 years, mean height 166.3±6.7 cm, mean weight 63.8±15.1 kg) and photographs of their habitual standing posture photographs were taken in the sagittal plane. For the evaluation of postural angles, reflective markers were placed on anatomical landmarks. For angular measurements, MB-ruler (Markus Bader- MB Software Solutions, triangular screen ruler) was used. Photographic evaluations were performed by two observers with a repetition after a week. Test-retest and inter-rater reliability evaluations were calculated using intra-class correlation coefficients (ICC). [Results] Inter-rater (ICC>0.972) and test-retest (ICC>0.774) reliability were found to be in the range of acceptable to excellent. [Conclusion] Reference angles for postural evaluation were found to be reliable and repeatable. The present method was found to be an easy and non-invasive method and it may be utilized by researchers who are in search of an alternative method for photographic postural assessments.

Craniofacial asymmetry in non-syndromic orthodontic subjects: clinical and postural evaluation

OBJECTIVE

The aim of this study was to evaluate the possible influence of a malocclusion pattern on a patient's posture.

METHODS

Patients affected by symmetric malocclusion or malocclusion with mild to moderate non-syndromic craniofacial asymmetry were submitted to a clinical and X-ray evaluation. Subjects with symmetric skeletal class I were used as the control group. Evaluation of differences in postural pattern was performed using rasterstereography.

RESULTS

Statistical analysis (t-test) was performed on 61 patients divided in homogeneous subgroups. The results show a pelvic torsion angle of 1.08° + 3.00° (P = 0.0023) (normal value (NV) = 0.0-1.9°) in subjects presenting skeletal class II z asymmetry (control group: 1.17° ± 1.25°, not significant (NS)).

CONCLUSIONS

The present study shows evidence of a relationship between malocclusion and spinal posture. A better understanding of the relationship between malocclusion and posture may help in planning a multidisciplinary approach that could involve other specialists.

Soreness during non-music activities is associated with playing-related musculoskeletal problems: an observational study of 731 child and adolescent instrumentalists

QUESTION

Is exposure to non-music-related activities associated with playing-related musculoskeletal problems in young instrumentalists? Is non-music-activity-related soreness associated with playing-related musculoskeletal problems in this group of instrumentalists?

DESIGN

Observational study using a questionnaire and physical measures.

PARTICIPANTS

859 instrumentalists aged 7 to 17 years from the School of Instrumental Music program.

RESULTS

Of the 731 respondents who completed the questionnaire adequately, 412 (56%) experienced instrument-playing problems; 219 (30%) had symptoms severe enough to interfere with normal playing. Children commonly reported moderate exposure to non-music-related activities, such as watching television (61%), vigorous physical activity (57%), writing (51%) and computer use (45%). Greater exposure to any non-music activity was not associated with playing problems, with odds ratios ranging from 1.01 (95% CI 0.7 to 1.5) for watching television to 2.08 (95% CI 0.5 to 3.3) for intensive hand activities. Four hundred and seventy eight (65%) children reported soreness related to non-music activities, such as vigorous physical activity (52%), writing (40%), computer use (28%), intensive hand activities (22%), electronic game use (17%) and watching television (15%). Non-music-activity-related soreness was significantly associated with instrument playing problems, adjusting for gender and age, with odds ratios ranging from 2.6 (95% CI 1.7 to 3.9) for soreness whilst watching television, to 4.3 (95% CI 2.6 to 7.1) for soreness during intensive hand activities.

CONCLUSION

Non-music-activity-related soreness co-occurs significantly with playing problems in young instrumentalists. The finding of significant co-occurrence of music and non-music-related soreness in respondents in this study suggests that intervention targets for young instrumentalists could include risk factors previously identified in the general child and adolescent population, as well as music-specific risk factors. This is an important consideration for the assessment and management of the musculoskeletal health of young musicians.

Screen-based media use clusters are related to other activity behaviours and health indicators in adolescents

Background

Screen-based media (SBM) occupy a considerable portion of young peoples’ discretionary leisure time. The aim of this paper was to investigate whether distinct clusters of SBM use exist, and if so, to examine the relationship of any identified clusters with other activity/sedentary behaviours and physical and mental health indicators.

Methods

The data for this study come from 643 adolescents, aged 14 years, who were participating in the longitudinal Western Australian Pregnancy Cohort (Raine) Study through May 2003 to June 2006. Time spent on SBM, phone use and reading was assessed using the Multimedia Activity Recall for Children and Adults. Height, weight, muscle strength were measured at a clinic visit and the adolescents also completed questionnaires on their physical activity and psychosocial health. Latent class analysis (LCA) was used to analyse groupings of SBM use.

Results

Three clusters of SBM use were found; C1 ‘instrumental computer users’ (high email use, general computer use), C2 ‘multi-modal e-gamers’ (both high console and computer game use) and C3 ‘computer e-gamers’ (high computer game use only). Television viewing was moderately high amongst all the clusters. C2 males took fewer steps than their male peers in C1 and C3 (-13,787/week, 95% CI: -4619 to -22957, p = 0.003 and -14,806, 95% CI: -5,306 to -24,305, p = 0.002) and recorded less MVPA than the C1 males (-3.5 h, 95% CI: -1.0 to -5.9, p = 0.005). There was no difference in activity levels between females in clusters C1 and C3.

Conclusion

SBM use by adolescents did cluster and these clusters related differently to activity/sedentary behaviours and both physical and psychosocial health indicators. It is clear that SBM use is not a single construct and future research needs to take consideration of this if it intends to understand the impact SBM has on health.

Development of a cost effective three-dimensional posture analysis tool: validity and reliability

BACKGROUND

The lack of clear understanding of the association between sitting posture and adolescent musculoskeletal pain, might reflect invalid and/or unreliable posture measurement instruments. The psychometric properties of any new measurement instrument should be demonstrated prior to use for research or clinical purposes. This paper describes psychometric testing of a new three-dimensional (3D), portable, non-invasive posture analysis tool (3D-PAT), from sequential studies using a mannequin and high school students.

METHODS

The first study compared the 3D-(X-, Y- and Z-) coordinates of reflective markers placed on a mannequin using the 3D-PAT, and the Vicon motion analysis system. This study also tested the reliability of taking repeated measures of the 3D-coordinates of the reflective markers. The second study determined the concurrent validity and test-retest reliability of the 3D-PAT measurements of nine sitting postural angles of high school students undertaking a standard computing task. In both studies, concordance correlation coefficients and Intraclass correlation coefficients described test-retest reliability, whilst Pearson product moment correlation coefficients and Bland-Altman plots demonstrated concurrent validity.

RESULTS

The 3D-PAT provides reliable and valid 3D measurements of five of the nine postural angles i.e. head flexion, neck flexion, cranio-cervical angle, trunk flexion and head lateral bending in adolescents undertaking a standard task.

CONCLUSIONS

The 3D-PAT is appropriate for research and clinical settings to measure five upper quadrant postural angles in three dimensions. As a measurement instrument it can provide further understanding of the relationship between sitting posture, changes to sitting posture and adolescent musculoskeletal pain.

Differences in standing and sitting postures of youth with idiopathic scoliosis from quantitative analysis of digital photographs

The objective of this study was to explore whether differences in standing and sitting postures of youth with idiopathic scoliosis could be detected from quantitative analysis of digital photographs. Standing and sitting postures of 50 participants aged 10-20-years-old with idiopathic scoliosis (Cobb angle: 15° to 60°) were assessed from digital photographs using a posture evaluation software program. Based on the XY coordinates of markers, 13 angular and linear posture indices were calculated in both positions. Paired t-tests were used to compare values of standing and sitting posture indices. Significant differences between standing and sitting positions (p < 0.05) were found for head protraction, shoulder elevation, scapula asymmetry, trunk list, scoliosis angle, waist angles, and frontal and sagittal plane pelvic tilt. Quantitative analysis of digital photographs is a clinically feasible method to measure standing and sitting postures among youth with scoliosis and to assist in decisions on therapeutic interventions.

Fat infiltration in the lumbar multifidus and erector spinae muscles in subjects with sway-back posture

AIM

Decreased activity of the lumbar stabilizer muscles has been identified in individuals with sway-back posture. Disuse can predispose these muscles to atrophy, which is characterized by a reduced cross-sectional area (CSA) and by fat infiltration. The aim of this study was to evaluate the amount of fat infiltration in the lumbar multifidus and lumbar erector spinae muscles as a sign of the muscle atrophy in individuals with sway-back posture, with and without low back pain.

MATERIALS AND METHODS

Forty-five sedentary individuals between 16 and 40 years old participated in this study. The sample was divided into three groups: symptomatic sway-back (SSBG) (n = 15), asymptomatic sway-back (ASBG) (n = 15), and control (CG) (n = 15). The individuals were first subjected to photographic analysis to classify their postures and were then referred for a magnetic resonance imaging (MRI) examination of the lumbar spine. The total (TCSA) and functional (FCSA) cross-sectional areas of the lumbar erector spinae together with lumbar multifidus and isolated lumbar multifidus muscles were measured from L1 to S1. The amount of fat infiltration was estimated as the difference between the TCSA and the FCSA.

RESULTS

Greater fat deposition was observed in the lumbar erector spinae and lumbar multifidus muscles of the individuals in the sway-back posture groups than in the control group. Pain may have contributed to the difference in the amount of fat observed in the groups with the same postural deviation. Similarly, sway-back posture may have contributed to the tissue substitution relative to the control group independently of low back pain.

CONCLUSIONS

The results of this study indicate that individuals with sway-back posture may be susceptible to morphological changes in their lumbar erector spinae and lumbar multifidus muscles, both due to the presence of pain and as a consequence of their habitual posture.

Clinical and radiological investigation of thoracic spine extension motion during bilateral arm elevation

STUDY DESIGN

Single-cohort laboratory-based study.

OBJECTIVES

To measure thoracic spine extension motion during bilateral arm elevation using functional radiography and photographic image analysis.

BACKGROUND

Impairment of thoracic spine extension motion may impact shoulder girdle function. Motion of the thoracic spine during arm movement has not been directly measured using functional radiographic analysis.

METHODS

In 21 asymptomatic men, thoracic kyphosis was measured in neutral standing and in end-range bilateral arm elevation, using lateral radiographs and photographic image analysis. Using both measurement techniques, the difference in thoracic kyphosis between the 2 body positions was used to quantify the range of extension motion of the thoracic spine. Bland-Altman plots were used to examine the agreement between measurement techniques. The relationship between the amount of thoracic kyphosis in neutral standing and kyphosis in full bilateral arm elevation was also examined.

RESULTS

The mean ± SD increase in thoracic extension with bilateral arm elevation was 12.8° ± 7.6° and 10.5° ± 4.4°, when measured from the radiographs and photographs, respectively. There was a significant correlation between the radiographic and photographic measurements of the amount of thoracic kyphosis measured in neutral posture (r = 0.71, P<.01) and for the kyphosis measured in full bilateral arm elevation (r = 0.79, P<.001). The mean difference between the 2 measurement techniques was 2.1° for kyphosis measured in neutral posture and 0.5° when measured in full bilateral arm elevation. The thoracic kyphosis angle measured in neutral posture was strongly correlated with the thoracic kyphosis angle measured in full bilateral arm elevation when measured with both radiographic (r = 0.80, P<.001) and photographic (r = 0.84, P<.001) techniques.

CONCLUSION

In asymptomatic men, bilateral arm elevation is associated with movement of the thoracic spine toward extension, but the amount of movement is variable among individuals.

The effect of camera location on observation-based posture estimation

This study used the observation-based method showing images on computer to evaluate angle estimation errors of 8 body segments in 3 motion planes at up to 28 segment angles and 5 camera locations with respect to goniometric measurements. Thirty observers participated in evaluating segment angles. Forearm (9.9°) and thigh (9.5°) had smaller errors than hand (14.0°) and foot had the smallest error (8.7°) due to its narrow range of motion (ROM). Errors were small with camera locations perpendicular to motions in the planes, such as 90° camera location for the flexion and extension of arm (6.3°), forearm (7.9°), thigh (6.5°), and leg (8.1°) in the sagittal plane. Segments had small errors of 3.1°, 4.6°, and 3.8° at segment angles of -90°, 0° and 90°, respectively. Care should be taken when estimating angles by the observation-based method for a specific segment motion and viewing direction is suggested to be perpendicular to the motion plane.

PRACTITIONER SUMMARY

Some companies may not allow many cameras or have obstacles for working posture evaluation in the workplace. These study results can be a guideline on proper selection of the number of cameras and their locations for a specific segment and its motion of interest to reduce visual segment angle estimation errors.

Inter-rater reliability of the evaluation of muscular chains associated with posture alterations in scoliosis

BACKGROUND

In the Global postural re-education (GPR) evaluation, posture alterations are associated with anterior or posterior muscular chain impairments. Our goal was to assess the reliability of the GPR muscular chain evaluation.

METHODS

DESIGN

Inter-rater reliability study. Fifty physical therapists (PTs) and two experts trained in GPR assessed the standing posture from photographs of five youths with idiopathic scoliosis using a posture analysis grid with 23 posture indices (PI). The PTs and experts indicated the muscular chain associated with posture alterations. The PTs were also divided into three groups according to their experience in GPR. Experts' results (after consensus) were used to verify agreement between PTs and experts for muscular chain and posture assessments. We used Kappa coefficients (K) and the percentage of agreement (%A) to assess inter-rater reliability and intra-class coefficients (ICC) for determining agreement between PTs and experts.

RESULTS

For the muscular chain evaluation, reliability was moderate to substantial for 12 PI for the PTs (%A: 56 to 82; K: 0.42 to 0.76) and perfect for 19 PI for the experts. For posture assessment, reliability was moderate to substantial for 12 PI for the PTs (%A > 60%; K: 0.42 to 0.75) and moderate to perfect for 18 PI for the experts (%A: 80 to 100; K: 0.55 to 1.00). The agreement between PTs and experts was good for most muscular chain evaluations (18 PI; ICC: 0.82 to 0.99) and PI (19 PI; ICC: 0.78 to 1.00).

CONCLUSIONS

The GPR muscular chain evaluation has good reliability for most posture indices. GPR evaluation should help guide physical therapists in targeting affected muscles for treatment of abnormal posture patterns.

Functional radiographic analysis of thoracic spine extension motion in asymptomatic men

OBJECTIVE

The purposes of this study were to examine the range of thoracic spine extension motion in a group of young, asymptomatic subjects and compare the radiologically derived measurements with those obtained using photographic analysis, and to examine the relationship between the magnitude of the neutral thoracic kyphosis and the range of thoracic spine extension motion.

METHODS

In 14 asymptomatic male subjects (mean age ± SD, 30.2 ± 7 years), the thoracic kyphosis in standing and full thoracic spine extension was measured from lateral thoracic spine radiographs and digital photographs. The difference between the 2 measurements was used to define the range of thoracic extension motion.

RESULTS

The range of thoracic extension motion measured radiologically was between 0 and 26° (mean ± SD, 12.0° ± 8.9°), whereas the photographic range was between 8° and 23° (mean ± SD, 12.4° ± 4.1°). There was a significant correlation between the photographic and radiographic measurements of extension range (r = 0.69, P < .01). Extension range of motion measured radiologically was significantly correlated with the magnitude of the thoracic kyphosis (r = 0.71, P < .01).

CONCLUSION

Functional radiographs of the thoracic spine can be used to measure the extension range of motion and define the extreme of range. The range of thoracic extension motion may be influenced by the magnitude of the neutral kyphosis. This technique may be used in future studies to evaluate the impact of spinal disorders on thoracic spine mobility.

An exploration of the relationship between back muscle endurance and familial, physical, lifestyle, and psychosocial factors in adolescents and young adults

STUDY DESIGN

Cross-sectional investigation.

OBJECTIVE

To explore the relationship between back muscle endurance (BME) and a range of familial, physical, lifestyle, and psychosocial variables in adolescents and young adults.

BACKGROUND

There is evidence that low back pain interventions which focus on improved BME are effective. However, the mechanisms associated with BME performance in adolescents and young adults are largely unclear. In particular, the potential familial relationship between parents and their children remains unexplored.

METHODS

This study utilized a subset of participants from the Joondalup Spinal Health Study cohort. One hundred nine children (47 boys, 62 girls) and 101 parents (39 fathers, 62 mothers) completed a series of physical, lifestyle, and psychosocial assessments. The univariable relationship between each covariate and BME was explored. Those found to have an association with child BME (P<.2) were included in an initial multivariable model and sequentially removed, until all remaining covariates were statistically significant (P<.05).

RESULTS

Mothers' BME performance was related to children's performance, accounting for 14.4% of the variance in the children's BME. Fathers' BME performance had a similar, albeit nonsignificant effect. Children's sitting trunk angle, pain sensitivity, percent trunk fat, waist girth, and body mass index were associated with their BME performance, accounting for between 5.2% and 20.9% of BME.

CONCLUSIONS

The final multivariable model, including mother's BME, percent trunk fat, and sitting trunk angle, explained 28% of the variance in BME performance, suggesting that for successful BME intervention a range of multidimensional variables should be considered.

Thoracic spine extension mobility in young adults: influence of subject position and spinal curvature

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

To examine extension mobility of the thoracic spine in young, asymptomatic adults, with particular reference to the influence of subject position and magnitude of the thoracic kyphosis.

BACKGROUND

Impairment of thoracic extension motion is commonly associated with mechanical pain disorders in this region of the spine. Knowledge of normal thoracic mobility and the factors that may influence this motion is important in the evaluation and management of thoracic pain disorders.

METHODS

In 40 asymptomatic adults, the total and regional thoracic extension range of motion was measured using 2-dimensional photographic image analysis. Extension mobility was measured in standing, sitting, prone, and 4-point kneeling. The association between the magnitude of the habitual thoracic kyphosis and extension mobility was also examined.

RESULTS

When measured from the habitual standing position, the mean range of flexion was 11.5° (3.7°) and mean extension range was 8.7° (3.7°). Thoracic extension was significantly greater in unloaded positions compared to loaded positions (P<.001). The standing thoracic kyphosis angle was significantly correlated with the end range thoracic extension angle in all positions (r = 0.63-0.79, P<.001). There was a poor correlation between the thoracic kyphosis angle and thoracic extension range of motion in all positions (r = 0.11-0.34, P>.06).

CONCLUSION

When measured from the habitual standing position, thoracic extension range of motion in young individuals is small and poorly correlated with the magnitude of the standing thoracic kyphosis. Unloaded positions (4-point kneeling and prone), compared to positions that load the spine (standing and sitting), appear to promote a greater range of thoracic extension motion.

Association of biopsychosocial factors with degree of slump in sitting posture and self-report of back pain in adolescents: a cross-sectional study

BACKGROUND

Conflicting evidence exists regarding relationships among sitting posture, factors that influence sitting posture, and back pain. This conflicting evidence may partially be due to the presence of multiple and overlapping factors associated with both sitting posture and back pain.

OBJECTIVE

The purpose of this study was to determine whether the degree of slump in sitting was associated with sex and other physical, lifestyle, or psychosocial factors. Additionally, the relationship between the report of back pain made worse by sitting and the degree of slump in sitting and other physical, lifestyle, or psychosocial factors was investigated.

DESIGN

This was a cross-sectional study.

METHODS

Adolescents (n=1,596) completed questionnaires to determine lifestyle and psychosocial profiles and the experience of back pain. Sagittal sitting posture, body mass index (BMI), and back muscle endurance (BME) were recorded. Standing posture subgroup categorization was determined.

RESULTS

Multivariate analysis revealed that the most significant factor associated with the degree of slump in sitting was male sex, followed by non-neutral standing postures, lower perceived self-efficacy, lower BME, greater television use, and higher BMI. Multivariable analysis indicated poorer Child Behaviour Checklist scores were the strongest correlate of report of back pain made worse by sitting, whereas degree of slump in sitting, female sex, and BME were more weakly related.

LIMITATIONS

Causality cannot be determined from this cross-sectional study, and 60% of sitting posture variation was not explained by the measured variables.

CONCLUSIONS

Slump in sitting was associated with physical correlates, as well as sex, lifestyle, and psychosocial factors, highlighting the complex, multidimensional nature of usual sitting posture in adolescents. Additionally, this study demonstrated that a greater degree of slump in sitting was only weakly associated with adolescent back pain made worse by sitting after adjustment for other physical and psychosocial factors.

Characteristics of chronic non-specific musculoskeletal pain in children and adolescents attending a rheumatology outpatients clinic: a cross-sectional study

BACKGROUND

Chronic non-specific musculoskeletal pain (CNSMSP) may develop in childhood and adolescence, leading to disability and reduced quality of life that continues into adulthood. The purpose of the study was to build a biopsychosocial profile of children and adolescents with CNSMSP.

METHODS

CNSMSP subjects (n = 30, 18 females, age 7-18) were compared with age matched pain free controls across a number of biopsychosocial domains.

RESULTS

In the psychosocial domain CNSMSP subjects had increased levels of anxiety and depression, and had more somatic pain complaints. In the lifestyle domain CNSMSP subjects had lower physical activity levels, but no difference in television or computer use compared to pain free subjects. Physically, CNSMSP subjects tended to sit with a more slumped spinal posture, had reduced back muscle endurance, increased presence of joint hypermobility and poorer gross motor skills.

CONCLUSION

These findings support the notion that CNSMSP is a multidimensional biopsychosocial disorder. Further research is needed to increase understanding of how the psychosocial, lifestyle and physical factors develop and interact in CNSMSP.

The between-day and inter-rater reliability of a novel wireless system to analyse lumbar spine posture

Lumbar posture is commonly assessed in non-specific chronic low back pain (NSCLBP), although quantitative measures have mostly been limited to laboratory environments. The BodyGuard™ is a spinal position monitoring device that can monitor posture in real time, both inside and outside the laboratory. The reliability of this wireless device was examined in 18 healthy participants during usual sitting and forward bending, two tasks that are commonly provocative in NSCLBP. Reliability was determined using intraclass correlation coefficients (ICC), the standard error of measurement (SEM), the mean difference and the minimal detectable change (MDC90). Between-day ICC values ranged from 0.84 to 0.87, with small SEM (5%), mean difference (<9%) and MDC90 (<14%) values. Inter-rater ICC values ranged from 0.91 to 0.94, with small SEM (4%), mean difference (6%) and MDC90 (9%) values. Between-day and inter-rater reliability are essential requirements for clinical utility and were excellent in this study. Further studies into the validity of this device and its application in clinical trials in occupational settings are required. STATEMENT OF RELEVANCE: A novel device that can analyse spinal posture exposure in occupational settings in a minimally invasive manner has been developed. This study established that the device has excellent between-day and inter-rater reliability in healthy pain-free subjects. Further studies in people with low back pain are planned.

The relationship between back muscle endurance and physical, lifestyle, and psychological factors in adolescents

STUDY DESIGN

Cross-sectional investigation.

BACKGROUND

There is some evidence that interventions directed to improving back muscle endurance (BME) in adolescents are effective in reducing low back pain, with anecdotal evidence of improved performance. However, the mechanisms responsible for this improvement remain unclear.

OBJECTIVE

To identify the relationship between physical, lifestyle, and psychological variables and BME in a large adolescent population, while controlling for back pain and gender.

METHODS

One thousand four-hundred thirty-five adolescents (702 females, 733 males; mean +/- SD age, 14.0 +/- 0.2 years) completed a range of physical, lifestyle, and psychological assessments. The group mean +/- SD height and body mass were 164 +/- 8 cm and 57.1 +/- 12.6 kg, respectively. Linear regression was used to investigate the univariate association between each of the physical, lifestyle, and psychological variables and BME. Backwards stepwise multivariate linear regression was used to determine statistically significant independent correlates of BME.

RESULTS

The final multivariate model explained 15.3% of the variance in BME and included at least 1 variable from the physical, lifestyle, and psychological domains. Adolescents who exercised less, watched more television, had a higher body mass index, sat in a more flexed trunk posture (more slumped), and had lower self-efficacy had lower BME.

CONCLUSIONS

All the physical and lifestyle variables linked with poorer BME performance in this investigation are indicative of reduced back muscle activation and/or deconditioning. Psychological predictors may have direct and/or indirect links with BME.

Relationships between prolonged neck/shoulder pain and sitting spinal posture in male and female adolescents

Neck/shoulder pain (NSP) is a common problem for adolescents and posture has been suggested as an important risk factor. The aim of this cross sectional study was to examine the relationship between prolonged NSP and habitual sitting posture in adolescents. The habitual sitting postures of 1593, 14-year-old adolescents with and without prolonged NSP were assessed using sagittal plane digital photographs. Cervicothoracic and lumbopelvic posture angles were calculated from the digital images using motion analysis software. Adolescents reported experience of NSP by questionnaire. Differences between postures of males and females and those with and without prolonged NSP were examined using independent t-tests. The relationships between cervicothoracic and lumbopelvic postures and presence of prolonged NSP were investigated using logistic regression models controlling for gender. Prolonged NSP was reported by 5.3% of the adolescents, with females reporting a higher prevalence rate (6.5%) than males (4.2%). Females also sat more erect with a more lordotic lumbar posture than males. Adolescents with prolonged NSP had more flexed cervicothoracic posture, more erect trunk and more lumbar lordosis. When gender was controlled, only lumbar lordosis was related to the presence of prolonged NSP.