Advancing Use of DEXA Scans to Quantitatively and Qualitatively Evaluate Lateral Spinal Curves, for Preliminary Identification of Adolescent Idiopathic Scoliosis

Dual-energy X-ray absorptiometry (DEXA) scan is an emerging screening method for identifying likely adolescent idiopathic scoliosis (AIS). Using DEXA in an unbiased population sample (the Raine Study), we aimed to report the inter-rater reliability and minimal detectable change (MDC₉₅) for scoliosis curve angle measurement, identify likely AIS prevalence, and the concordance between reported AIS diagnosis and DEXA-identified likely AIS. Scoliosis curve angles were measured using the modified Ferguson method on DEXA scans (n = 1238) at age 20 years. For curve angle inter-rater reliability, two examiners measured angles (6-40°) on 41 scans. Likely, AIS was determined with quantitative and qualitative criteria (modified Ferguson angles ≥ 10° and expert review of spinal curves).The inter-rater reliability for scoliosis curve angle measurement was good-excellent (ICC: 0.82; 95% CI: 0.71-0.89; p < 0.001), and MDC₉₅ was 6.2°. The prevalence of likely AIS was 2.1% (26/1238). Diagnosis of AIS was reported despite little or no scoliosis curve (< 3.8°) for 20 participants (1.6%), and diagnosis of AIS was not reported despite scoliosis curve ≥ 10° for 11 participants (0.9%). Results support the use of modified Ferguson method to measure scoliosis curve angles on DEXA. There is potential utility for using a combination of quantitative measurement and qualitative criteria to evaluate DEXA images, to identify likely AIS for reporting prevalence. Without formal school screening, the analysis of DEXA in this population sample suggested that relying on current health professional diagnosis alone could result in 2.5% of this cohort being at risk of false positive diagnosis or delay in necessary management due to non-diagnosis of AIS.

A crossover randomised and controlled trial of the impact of active video games on motor coordination and perceptions of physical ability in children at risk of Developmental Coordination Disorder

BACKGROUND

Impaired motor development can significantly affect a child's life and may result in an increased risk of a range of physical and psychological disorders. Active video game (AVG) interventions have been demonstrated to enhance motor skills in children with Developmental Coordination Disorder (DCD); however a home-based intervention has not been assessed.

OBJECTIVES

The primary aim of this study was to compare the changes in motor coordination between a 16 week period of AVG use, with 16 weeks of normal activities (NAG). The secondary aim was to compare the child and parent perceptions of their physical performance between the AVG and NAG conditions.

METHODS

Twenty-one 9-12 year olds (10 males) were confirmed to be at risk of DCD (⩽ 16th percentile Movement Assessment Battery for Children-2nd edition (MABC-2) and ⩽ 15th percentile Developmental Coordination Disorder Questionnaire (DCDQ)) and participated in this crossover randomised and controlled trial. Data was collected at study entry, after the first 16 week condition and following the final 16 week condition, including; (1) the MABC-2, (2) three-dimensional motion analysis of single leg balance and finger-nose tasks, and (3) parent perception of physical skills. Participant perception of physical skills was collected only after the first and second conditions.

RESULTS

There was no significant difference between AVG and NAG for any of the primary variables including the MABC-2, balance centre-of-mass path distance and finger-nose path distance. There was no significant intervention effect for secondary measures of motor coordination; however the children perceived their motor skills to be significantly enhanced as a result of the AVG intervention in comparison to the period of no intervention.

CONCLUSION

A 16 week home based AVG intervention did not enhance motor skills in children with DCD, although they perceived their physical skills to be significantly improved.

TRIAL REGISTRATION

Australia and New Zealand Clinical trials Registry (ACTRN 12611000400965).

A workplace exercise versus health promotion intervention to prevent and reduce the economic and personal burden of non-specific neck pain in office personnel: protocol of a cluster-randomised controlled trial

INTRODUCTION

Non-specific neck pain is a major burden to industry, yet the impact of introducing a workplace ergonomics and exercise intervention on work productivity and severity of neck pain in a population of office personnel is unknown.

RESEARCH QUESTION

Does a combined workplace-based best practice ergonomic and neck exercise program reduce productivity losses and risk of developing neck pain in asymptomatic workers, or decrease severity of neck pain in symptomatic workers, compared to a best practice ergonomic and general health promotion program?

DESIGN

Prospective cluster randomised controlled trial.

PARTICIPANTS AND SETTING

Office personnel aged over 18 years, and who work>30 hours/week.

INTERVENTION

Individualised best practice ergonomic intervention plus 3×20 minute weekly, progressive neck/shoulder girdle exercise group sessions for 12 weeks.

CONTROL

Individualised best practice ergonomic intervention plus 1-hour weekly health information sessions for 12 weeks.

MEASUREMENTS

Primary (productivity loss) and secondary (neck pain and disability, muscle performance, and quality of life) outcome measures will be collected using validated scales at baseline, immediate post-intervention and 12 months after commencement.

PROCEDURE

640 volunteering office personnel will be randomly allocated to either an intervention or control arm in work group clusters.

ANALYSIS

Analysis will be on an 'intent-to-treat' basis and per protocol. Multilevel, generalised linear models will be used to examine the effect of the intervention on reducing the productivity loss in dollar units (AUD), and severity of neck pain and disability.

DISCUSSION

The findings of this study will have a direct impact on policies that underpin the prevention and management of neck pain in office personnel.

Reducing occupational sedentary time: a systematic review and meta-analysis of evidence on activity-permissive workstations

Excessive sedentary time is detrimentally linked to obesity, type 2 diabetes, cardiovascular disease and premature mortality. Studies have been investigating the use of activity-permissive workstations to reduce sedentary time in office workers, a highly sedentary target group. This review systematically summarizes the evidence for activity-permissive workstations on sedentary time, health-risk biomarkers, work performance and feasibility indicators in office workplaces. In July 2013, a literature search identified 38 relevant peer-reviewed publications. Key findings were independently extracted by two researchers. The average intervention effect on sedentary time was calculated via meta-analysis. In total, 984 participants across 19 field-based trials and 19 laboratory investigations were included, with sample sizes ranging from n = 2 to 66 per study. Sedentary time, health-risk biomarkers and work performance indicators were reported in 13, 23 and 23 studies, respectively. The pooled effect size from the meta-analysis was -77 min of sedentary time/8-h workday (95% confidence interval = -120, -35 min). Non-significant changes were reported for most health- and work-related outcomes. Studies with acceptability measures reported predominantly positive feedback. Findings suggest that activity-permissive workstations can be effective to reduce occupational sedentary time, without compromising work performance. Larger and longer-term randomized-controlled trials are needed to understand the sustainability of the sedentary time reductions and their longer-term impacts on health- and work-related outcomes.

Gender differences in the relationships between lean body mass, fat mass and peak bone mass in young adults

The relationships between fat mass and bone mass in young adults are unclear. In 1,183 young Australians, lean body mass had a strong positive relationship with total body bone mass in both genders. Fat mass was a positive predictor of total body bone mass in females, with weaker association in males.

INTRODUCTION

Body weight and lean body mass are established as major determinants of bone mass, but the relationships between fat mass (including visceral fat) and peak bone mass in young adults are unclear. The aim of this study was to evaluate the associations between bone mass in young adults and three body composition measurements: lean body mass, fat mass and trunk-to-limb fat mass ratio (a surrogate measure of visceral fat).

METHODS

Study participants were 574 women and 609 men aged 19-22 years from the Raine study. Body composition, total body bone mineral content (TBBMC), bone area and areal bone mineral density (TBBMD) were measured using DXA.

RESULTS

In multivariate linear regression models with height, lean body mass, fat mass and trunk-to-limb fat mass ratio as predictor variables, lean mass was uniquely associated with the largest proportion of variance of TBBMC and TBBMD in males (semi-partial R(2) 0.275 and 0.345, respectively) and TBBMC in females (semi-partial R(2) 0.183). Fat mass was a more important predictor of TBBMC and TBBMD in females (semi-partial R(2) 0.126 and 0.039, respectively) than males (semi-partial R(2) 0.006 and 0.018, respectively). Trunk-to-limb fat mass ratio had a weak, negative association with TBBMC and bone area in both genders (semi-partial R(2) 0.004 to 0.034).

CONCLUSIONS

Lean body mass has strong positive relationship with total body bone mass in both genders. Fat mass may play a positive role in peak bone mass attainment in women but the association was weaker in men; different fat compartments may have different effects.

A clinician's guide to work-related assessments: 1 - purposes and problems

This paper is the first of a series aimed at providing clinicians with a guide to assist them in using work-related assessments appropriately. The context of work-related assessments is described using a model. The purposes of work-related assessments are classified and discussed using the proposed model. The 10 major problems facing clinicians using work-related assessments are outlined. Companion papers describe the design, administration and interpretation problems in detail.

A clinician's guide to work-related assessments: 3 - Administration and interpretation problems

This paper is the third of a series aimed at providing clinicians with a guide to assist them in using work-related assessments appropriately. The major administration and interpretation problems facing clinicians using work-related assessments are described in detail. Administration problems are: (1) insufficient evidence of reliability and validity; and (2) potential examiner bias. Interpretation problems are: (1) inappropriate use of norm and criterion-referenced data; (2) inappropriate statistical manipulation of results; (3) difficulty in determining end-point; and (4) difficulty determining sincerity of effort. Companion papers describe the purposes of work-related assessments, and design problems in detail.

A clinician's guide to work-related assessments: 2 - design problems

This paper is the second in a series aimed at providing clinicians with a guide to assist them in using work-related assessments appropriately. This paper discusses the four major design problems facing clinicians using work-related assessments. These problems are: (1) a confused definition of terms; (2) confused conceptual basis; (3) separation of the individual from the context and the environment; and (4) lack of assessment of psychosocial/cognitive aspects related to work. Suggestions are provided to assist clinicians in making decisions regarding work-related assessments. Recommendations for further research to ameliorate these problems are also made. Companion papers describe the purposes of work-related assessments, and administration and interpretation problems in detail.

Evidence-based guidelines for the wise use of computers by children: physical development guidelines

Computer use by children is common and there is concern over the potential impact of this exposure on child physical development. Recently principles for child-specific evidence-based guidelines for wise use of computers have been published and these included one concerning the facilitation of appropriate physical development. This paper reviews the evidence and presents detailed guidelines for this principle. The guidelines include encouraging a mix of sedentary and whole body movement tasks, encouraging reasonable postures during computing tasks through workstation, chair, desk, display and input device selection and adjustment and special issues regarding notebook computer use and carriage, computing skills and responding to discomfort. The evidence limitations highlight opportunities for future research. The guidelines themselves can inform parents and teachers, equipment designers and suppliers and form the basis of content for teaching children the wise use of computers. STATEMENT OF RELEVANCE: Many children use computers and computer-use habits formed in childhood may track into adulthood. Therefore child-computer interaction needs to be carefully managed. These guidelines inform those responsible for children to assist in the wise use of computers.

Principles for the wise use of computers by children

Computer use by children at home and school is now common in many countries. Child computer exposure varies with the type of computer technology available and the child's age, gender and social group. This paper reviews the current exposure data and the evidence for positive and negative effects of computer use by children. Potential positive effects of computer use by children include enhanced cognitive development and school achievement, reduced barriers to social interaction, enhanced fine motor skills and visual processing and effective rehabilitation. Potential negative effects include threats to child safety, inappropriate content, exposure to violence, bullying, Internet 'addiction', displacement of moderate/vigorous physical activity, exposure to junk food advertising, sleep displacement, vision problems and musculoskeletal problems. The case for child specific evidence-based guidelines for wise use of computers is presented based on children using computers differently to adults, being physically, cognitively and socially different to adults, being in a state of change and development and the potential to impact on later adult risk. Progress towards child-specific guidelines is reported. Finally, a set of guideline principles is presented as the basis for more detailed guidelines on the physical, cognitive and social impact of computer use by children. The principles cover computer literacy, technology safety, child safety and privacy and appropriate social, cognitive and physical development. The majority of children in affluent communities now have substantial exposure to computers. This is likely to have significant effects on child physical, cognitive and social development. Ergonomics can provide and promote guidelines for wise use of computers by children and by doing so promote the positive effects and reduce the negative effects of computer-child, and subsequent computer-adult, interaction.

The influence of desk and display design on posture and muscle activity variability whilst performing information technology tasks

Desk design and computer display height can affect posture and muscle activation during computer use. Amplitudes of postural variables and muscle activity during computer use do not explain the results from epidemiological studies of musculoskeletal discomfort and disorders related to computer use. The purpose of this study was to assess variability of posture and muscle activity during work with two computer display heights and book/paper, in conjunction with a curved desk designed to provide forearm support and a traditional, straight desk. 18 male and 18 female participants performed 10-min tasks involving keying, mousing, reading and writing in six desk/display conditions. 3D posture and surface emg were assessed for the final 2 min of each task. The curved desk resulted in greater postural and muscle activity variation, suggesting an advantage of this supportive surface over the straight desk. There was little difference in variability associated with the two display heights. However, greater variability of posture and muscle activity was evident with the book/paper condition. Non-touch typists had greater neck flexion variation. The design of information technology tasks and workstations can influence the short term variation in posture and muscle activity. Variation is influenced independently of mean postures and muscle amplitudes and therefore needs to be considered to adequately assess the risk of musculoskeletal disorders.

Effect of visual display height on modelled upper and lower cervical gravitational moment, muscle capacity and relative strain

Head and neck posture is an important factor in neck pain related to computer use; however, the evidence for an optimal posture is unconvincing. This study measured the 3-D postures of 36 young adults during use of three different display heights. Cervical extensor muscle strain was estimated using modelled gravitational load moments and muscle capacities. The influence of more or less upper vs. lower cervical movement was also explored across a broad range of potential postures. Overall cervical extensor muscle capacity diminished away from a neutral posture whilst gravity moment increased with flexion. Overall cervical extensor muscle strain increased with head flexion but remained stable into head extension. Individual differences in the amount of upper and lower cervical movement had an important effect on strain, particularly for some muscles. Computer display height guidelines are an important component of ergonomics practice, yet the relative strain on neck extensor muscles as a function of display height has not been examined. The current findings provide more detailed biomechanical evidence that ergonomists can incorporate with usability and other evidence to determine appropriate display height recommendations.

The impact of computer display height and desk design on muscle activity during information technology work by young adults

Computer display height and desk design are believed to be important workstation features and are included in international standards and guidelines. However, the evidence base for these guidelines is lacking a comparison of neck/shoulder muscle activity during computer and paper tasks and whether forearm support can be provided by desk design. This study measured the spinal and upper limb muscle activity in 36 young adults whilst they worked in different computer display, book and desk conditions. Display height affected spinal muscle activity with paper tasks resulting in greater mean spinal and upper limb muscle activity. A curved desk resulted in increased proximal muscle activity. There was no substantial interaction between display and desk.

The impact of computer display height and desk design on 3D posture during information technology work by young adults

Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.

Optimizing the interaction of children with information and communication technologies

This paper outlines the major changes in the lives of children in industrially advanced countries associated with the increased interaction with information and communication technologies. The potential opportunities and threats to the cognitive, social, physical and visual development of children are reviewed to emphasize the importance of optimizing the interaction. The change in children's use of technology also poses opportunities and threats for ergonomics that should be noted if the profession is to continue being relevant and useful into this century. The paper ends with a pathway to the development and implementation of guidelines about child information and communication technology use for different groups of guideline users.

A randomized and controlled trial of a participative ergonomics intervention to reduce injuries associated with manual tasks: physical risk and legislative compliance

A participative ergonomics approach to reducing injuries associated with manual tasks is widely promoted; however only limited evidence from uncontrolled trials has been available to support the efficacy of such an approach. This paper reports on a randomized and controlled trial of PErforM, a participative ergonomics intervention designed to reduce the risks of injury associated with manual tasks. One hundred and seventeen small to medium sized food, construction, and health workplaces were audited by government inspectors using a manual tasks risk assessment tool (ManTRA). Forty-eight volunteer workplaces were then randomly assigned to Experimental and Control groups with the Experimental group receiving the PErforM program. Inspectors audited the workplaces again, 9 months following the intervention. The results showed a significant decrease in estimates of manual task risk and suggested better legal compliance in the Experimental group.

Patient handling with and without slings: an analysis of the risk of injury to the lumbar spine

Health professionals handling patients are known to be at risk of sustaining work related low back injuries. It is not known whether the use of lifting slings reduces the risk of injury to the lumbar spine for patient handlers. This study used kinematic variables and subjective ratings of body part stress and lifter preference as measures of relative risk for three two-person techniques for carrying a patient from one chair to another chair. The techniques used no slings, one and two slings respectively. Twenty-two nurses performed five trials each of the three techniques. Kinematic measures of angular displacement, velocity and acceleration were obtained using the lumbar motion monitor and visual analogue scales were used to obtain measures of body part stress for seven body parts. Angular displacement, velocity and acceleration were significantly greater (p < 0.05) in the frontal, sagittal and transverse planes for the no sling technique compared to techniques using slings. Comparatively small yet significant differences between techniques using slings were recorded for sagittal flexion and rotation. There was no significant difference between one and two sling techniques for other dependent variables. Mean total body stress rating was higher for the no sling technique and all subjects indicated that their first preference was for slings. Although all three measures of risk rated the no sling technique as carrying a higher level of risk than the techniques using slings. No single measure adequately captured all aspects of relative risk. The elimination of manual patient handling is thought to be the best option for the reduction of work related back injuries in patient handlers. Where resources or technology are not yet adequate to provide practical alternatives and where the use of manual technique for a seat to seat task is unavoidable, the use of patient handling slings will reduce the risk.

A comparison of the postures assumed when using laptop computers and desktop computers

This study evaluated the postural implications of using a laptop computer. Laptop computer screens and keyboards are joined, and are therefore unable to be adjusted separately in terms of screen height and distance, and keyboard height and distance. The posture required for their use is likely to be constrained, as little adjustment can be made for the anthropometric differences of users. In addition to the postural constraints, the study looked at discomfort levels and performance when using laptops as compared with desktops. Statistical analysis showed significantly greater neck flexion and head tilt with laptop use. The other body angles measured (trunk, shoulder, elbow, wrist, and scapula and neck protraction/retraction) showed no statistical differences. The average discomfort experienced after using the laptop for 20 min, although appearing greater than the discomfort experienced after using the desktop, was not significantly greater. When using the laptop, subjects tended to perform better than when using the desktop, though not significantly so. Possible reasons for the results are discussed and implications of the findings outlined.