Occupational low back pain is a significant problem among nurses. Recent literature suggests curr... more Occupational low back pain is a significant problem among nurses. Recent literature suggests current occupational preventative strategies for nurses have not been effective. Given low back pain is already prevalent before commencing employment, nursing students should be the target of preventative interventions. Modifiable personal factors which contribute to low back pain have proven difficult to identify, but are thought to play an important role in the biopsychosocial nature of low back pain. To evaluate the contribution of personal biopsychosocial factors to low back pain in nursing students. Cross-sectional study comprising physical testing and questionnaires. Two university undergraduate nursing schools in Western Australia. 170 female undergraduate nursing students. Low back pain and control subjects were compared across social, lifestyle (physical activity), psychological (stress, anxiety, depression, back pain beliefs, coping strategies and catastrophising) and physical (spinal postures and spinal kinematics in functional tasks, leg and back muscle endurance, spinal repositioning error and cardiovascular fitness) characteristics. Low back pain was considered as either "minor" or "significant" depending upon pain severity, duration, impact and level of disability. Over 30% of all subjects (mean age 22.5+/-4.5 years) reported "significant" low back pain in the preceding 12 months. Univariate analysis: social measures did not distinguish between groups. Subjects with "significant" low back pain were more physically active (p=0.04), had higher stress scores (p=0.01) and used passive coping strategies (p<0.001) more than other subjects. "Significant" low back pain subjects held their lower lumbar spine in a more extended posture during transfers at bed height than other subjects. No differences between groups were found for sagittal spinal mobility, static spinal posture, muscle endurance, spinal repositioning error, cardiovascular fitness or other psychological measures. Multivariate analysis: regression analysis revealed stress, coping, physical activity, spinal kinematics, and age all contributed independently to the presence of low back pain, representing a significant 23% of variance. Modifiable lifestyle, psychological and physical factors were independently associated with low back pain in nursing students. Targeting personal factors associated with low back pain in nursing students, rather than occupational factors in working nurses may help improve the impact of low back pain in nurses. Prospective studies are…
Capturing the complex time pattern of physical activity (PA) and sedentary behavior (SB) using ac... more Capturing the complex time pattern of physical activity (PA) and sedentary behavior (SB) using accelerometry remains a challenge. Research from occupational health suggests exposure variation analysis (EVA) could provide a meaningful tool. This paper (1) explains the application of EVA to accelerometer data, (2) demonstrates how EVA thresholds and derivatives could be chosen and used to examine adherence to PA and SB guidelines, and (3) explores the validity of EVA outputs. EVA outputs are compared with accelerometer data from 4 individuals (Study 1a and 1b) and 3 occupational groups (Study 2): seated workstation office workers (n = 8), standing workstation office workers (n = 8), and teachers (n = 8). Line graphs and related EVA graphs highlight the use of EVA derivatives for examining compliance with guidelines. EVA derivatives of occupational groups confirm no difference in bouts of activity but clear differences as expected in extended bouts of SB and brief bursts of activity, t...
To evaluate the impact of (1) the removal of home access to traditional electronic games or (2) t... more To evaluate the impact of (1) the removal of home access to traditional electronic games or (2) their replacement with active input electronic games, on daily physical activity and sedentary behaviour in children aged 10-12 years. Crossover randomised controlled trial, over 6 months. Family homes in metropolitan Perth, Australia from 2007 to 2010. 10-year-old to 12-year-old children were recruited through school and community media. From 210 children who were eligible, 74 met inclusion criteria, 8 withdrew and 10 had insufficient primary outcome measures, leaving 56 children (29 female) for analysis. A counterbalanced randomised order of three conditions sustained for 8 weeks each: no home access to electronic games, home access to traditional electronic games and home access to active input electronic games. Primary outcome was accelerometer assessed moderate/vigorous physical activity (MVPA). Secondary outcomes included sedentary time and diary assessed physical activity and seden...
Electronic games (e-games) are widely used by children, often for substantial durations, yet to d... more Electronic games (e-games) are widely used by children, often for substantial durations, yet to date there are no evidence-based guidelines regarding their use. The aim of this paper is to present guidelines for the wise use of e-games by children based on a narrative review of the research. This paper proposes a model of factors that influence child-e-games interaction. It summarises the evidence on positive and negative effects of use of e-games on physical activity and sedentary behaviour, cardio-metabolic health, musculoskeletal health, motor coordination, vision, cognitive development and psychosocial health. Available guidelines and the role of guidelines are discussed. Finally, this information is compiled into a clear set of evidence-based guidelines, about wise use of e-games by children, targeting children, parents, professionals and the e-game industry. These guidelines provide an accessible synthesis of available knowledge and pragmatic guidelines based on e-game specifi...
International Journal of Industrial Ergonomics, 2005
The study compared the EMG changes and discomforts experienced by a symptomatic and an asymptomat... more The study compared the EMG changes and discomforts experienced by a symptomatic and an asymptomatic group of office workers when they were challenged by the physical stressors of increased typing speed and increased typing force. 21 female office workers were recruited in the Case Group and 20 in the Control Group. Each subject had to perform 20min of typing in
Work-related neck and upper limb disorders (WRNULD) are common problems among office workers who ... more Work-related neck and upper limb disorders (WRNULD) are common problems among office workers who use computers intensively and maintain prolonged static postures. These disorders have often been attributed to result from sustained muscle activity in the neck–shoulder musculature. The present study examined whether symptomatic subjects exhibited the same muscle activity patterns as asymptomatic controls when they performed a prolonged computer
Is exposure to non-music-related activities associated with playing-related musculoskeletal probl... more 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? Observational study using a questionnaire and physical measures. 859 instrumentalists aged 7 to 17 years from the School of Instrumental Music program. 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. 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. [Ranelli S, Straker L, Smith A (2014) Soreness during non-music activities is associated with playing-related musculoskeletal problems: an observational study of 731 child and adolescent intrumentalists.Journal of Physiotherapy60: 102-108].
ObjectivesResearchers investigating the effects of computer use and the development of musculoske... more ObjectivesResearchers investigating the effects of computer use and the development of musculoskeletal disorders have mainly focused on the effects of prolonged muscle loading associated with postures assumed during computer use in the adult population. The objective of this study was to investigate the effects of different forms of old and new information technology (IT) on muscle activity levels in a
Prolonged static posture has been identified as a major risk factor for work-related neck and upp... more Prolonged static posture has been identified as a major risk factor for work-related neck and upper limb disorders (WRNULD) in computer users. Previous research has mainly examined working postures in healthy pain-free individuals. The present study examined whether symptomatic subjects exhibited the same kinematic patterns as asymptomatic controls during a prolonged computer task. In a Case–Control comparison, female office workers
International Journal of Industrial Ergonomics - INT J IND ERGONOMIC, 2006
This paper argues for the systematic development and presentation of evidence-based guidelines fo... more This paper argues for the systematic development and presentation of evidence-based guidelines for appropriate use of computers by children. The currently available guidelines are characterised and a proposed conceptual model presented. Five principles are presented as a foundation to the guidelines. The paper concludes with a framework for the guidelines, key evidence for and against guidelines, and gaps in the available evidence, with the aim of facilitating further discussion.
Engaging in low levels of physical activity (PA) and accumulating prolonged periods of sedentary ... more Engaging in low levels of physical activity (PA) and accumulating prolonged periods of sedentary behavior (SB) during daily life have been associated with deleterious health outcomes. The objective of this study was to undertake an analysis of the way in which PA and SB were accumulated after bariatric surgery. Adults 12 to 18 months after laparoscopic adjustable gastric banding or 6 to 18 months after laparoscopic sleeve gastrectomy wore 2 activity monitors during the waking hours for 7 days. Anthropometric and demographic data were recorded. Data were available on 40 participants (30 females; median ± interquartile range: age 46 ± 16 years, time since surgery 14 ± 8 months, body mass index 36 ± 9 kg/m(2)). The proportion of waking hours spent in SB, light PA, moderate PA, and vigorous PA was 72% ± 12%, 22% ± 9%, 5% ± 3% and 0% ± 0%, respectively. Half of the time in SB was accumulated in uninterrupted bouts ≥ 30 minutes. Almost all PA was accumulated in bouts<10 minutes in duration. The median daily step count was 9108 ± 4360. The proportion of people who completed an average of ≥ 10,000 steps/d was similar to that reported in Western Australian adults (39% versus 32%; P = .35). Our sample spent>70% of time in SB, half of which was accumulated in uninterrupted bouts ≥ 30 minutes. Very little time was spent in moderate or vigorous PA (5%), and this was accumulated in short bouts (<10 minutes). Healthcare professionals should target not just overall time in SB and PA, but also aim to reduce prolonged periods of SB and increase sustained periods of PA.
Objective: This study aimed to determine the effects of active workstation designs on speed and e... more Objective: This study aimed to determine the effects of active workstation designs on speed and error during typing, mouse pointing, and combined type and mouse-use tasks. Background: Office ergonomics has focused on musculoskeletal disorder prevention; however, increasing computer-based work also increases health risks associated with inactivity. Workstations allowing computer users to walk or cycle while performing computer tasks have been shown to demand sufficient energy expenditure to result in significant health benefits. However the performance effects of being active while using a computer have not been documented. Method: Thirty office workers (16 female, 15 touch typists) performed standardized computer tasks in six workstation conditions: sitting, standing, walking at 1.6 km/h and 3.2 km/h, and cycling at 5 and 30 watts. Performance, perceived performance, and heart rate were measured. Results: Computer task performance was lower when walking and slightly lower when cycli...
Use of computers by children has increased rapidly, however few studies have addressed factors wh... more Use of computers by children has increased rapidly, however few studies have addressed factors which may reduce musculoskeletal stress during computer use by children. This study quantified the postural and muscle activity effects of providing forearm support when children used computers. Twelve male and 12 female children (10–12 years) who regularly used computers were recruited. Activities were completed using a
The Animal Fun program was designed to enhance the motor ability of young children by imitating t... more The Animal Fun program was designed to enhance the motor ability of young children by imitating the movements of animals in a fun, inclusive setting. The efficacy of this program was investigated through a randomized controlled trial using a multivariate nested cohort design. Pre-intervention scores were recorded for 511 children aged 4.83 years to 6.17 years (M=5.42 years, SD=3.58 months). Six control and six intervention schools were compared 6 months later following the intervention, and then again at 18 months after the initial testing when the children were in their first school year. Changes in motor performance were examined using the Bruininks-Oseretsky Test of Motor Proficiency short form. Data were analyzed using multi-level-mixed effects linear regression. A significant Condition×Time interaction was found, F(2,1219)=3.35, p=.035, demonstrating that only the intervention group showed an improvement in motor ability. A significant Sex×Time interaction was also found, F(2,1219)=3.84, p=.022, with boys improving over time, but not girls. These findings have important implications for the efficacy of early intervention of motor skills and understanding the differences in motor performance between boys and girls.
Head and neck posture is an important factor in neck pain related to computer use; however, the e... more 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.
Occupational low back pain is a significant problem among nurses. Recent literature suggests curr... more Occupational low back pain is a significant problem among nurses. Recent literature suggests current occupational preventative strategies for nurses have not been effective. Given low back pain is already prevalent before commencing employment, nursing students should be the target of preventative interventions. Modifiable personal factors which contribute to low back pain have proven difficult to identify, but are thought to play an important role in the biopsychosocial nature of low back pain. To evaluate the contribution of personal biopsychosocial factors to low back pain in nursing students. Cross-sectional study comprising physical testing and questionnaires. Two university undergraduate nursing schools in Western Australia. 170 female undergraduate nursing students. Low back pain and control subjects were compared across social, lifestyle (physical activity), psychological (stress, anxiety, depression, back pain beliefs, coping strategies and catastrophising) and physical (spinal postures and spinal kinematics in functional tasks, leg and back muscle endurance, spinal repositioning error and cardiovascular fitness) characteristics. Low back pain was considered as either "minor" or "significant" depending upon pain severity, duration, impact and level of disability. Over 30% of all subjects (mean age 22.5+/-4.5 years) reported "significant" low back pain in the preceding 12 months. Univariate analysis: social measures did not distinguish between groups. Subjects with "significant" low back pain were more physically active (p=0.04), had higher stress scores (p=0.01) and used passive coping strategies (p<0.001) more than other subjects. "Significant" low back pain subjects held their lower lumbar spine in a more extended posture during transfers at bed height than other subjects. No differences between groups were found for sagittal spinal mobility, static spinal posture, muscle endurance, spinal repositioning error, cardiovascular fitness or other psychological measures. Multivariate analysis: regression analysis revealed stress, coping, physical activity, spinal kinematics, and age all contributed independently to the presence of low back pain, representing a significant 23% of variance. Modifiable lifestyle, psychological and physical factors were independently associated with low back pain in nursing students. Targeting personal factors associated with low back pain in nursing students, rather than occupational factors in working nurses may help improve the impact of low back pain in nurses. Prospective studies are…
Capturing the complex time pattern of physical activity (PA) and sedentary behavior (SB) using ac... more Capturing the complex time pattern of physical activity (PA) and sedentary behavior (SB) using accelerometry remains a challenge. Research from occupational health suggests exposure variation analysis (EVA) could provide a meaningful tool. This paper (1) explains the application of EVA to accelerometer data, (2) demonstrates how EVA thresholds and derivatives could be chosen and used to examine adherence to PA and SB guidelines, and (3) explores the validity of EVA outputs. EVA outputs are compared with accelerometer data from 4 individuals (Study 1a and 1b) and 3 occupational groups (Study 2): seated workstation office workers (n = 8), standing workstation office workers (n = 8), and teachers (n = 8). Line graphs and related EVA graphs highlight the use of EVA derivatives for examining compliance with guidelines. EVA derivatives of occupational groups confirm no difference in bouts of activity but clear differences as expected in extended bouts of SB and brief bursts of activity, t...
To evaluate the impact of (1) the removal of home access to traditional electronic games or (2) t... more To evaluate the impact of (1) the removal of home access to traditional electronic games or (2) their replacement with active input electronic games, on daily physical activity and sedentary behaviour in children aged 10-12 years. Crossover randomised controlled trial, over 6 months. Family homes in metropolitan Perth, Australia from 2007 to 2010. 10-year-old to 12-year-old children were recruited through school and community media. From 210 children who were eligible, 74 met inclusion criteria, 8 withdrew and 10 had insufficient primary outcome measures, leaving 56 children (29 female) for analysis. A counterbalanced randomised order of three conditions sustained for 8 weeks each: no home access to electronic games, home access to traditional electronic games and home access to active input electronic games. Primary outcome was accelerometer assessed moderate/vigorous physical activity (MVPA). Secondary outcomes included sedentary time and diary assessed physical activity and seden...
Electronic games (e-games) are widely used by children, often for substantial durations, yet to d... more Electronic games (e-games) are widely used by children, often for substantial durations, yet to date there are no evidence-based guidelines regarding their use. The aim of this paper is to present guidelines for the wise use of e-games by children based on a narrative review of the research. This paper proposes a model of factors that influence child-e-games interaction. It summarises the evidence on positive and negative effects of use of e-games on physical activity and sedentary behaviour, cardio-metabolic health, musculoskeletal health, motor coordination, vision, cognitive development and psychosocial health. Available guidelines and the role of guidelines are discussed. Finally, this information is compiled into a clear set of evidence-based guidelines, about wise use of e-games by children, targeting children, parents, professionals and the e-game industry. These guidelines provide an accessible synthesis of available knowledge and pragmatic guidelines based on e-game specifi...
International Journal of Industrial Ergonomics, 2005
The study compared the EMG changes and discomforts experienced by a symptomatic and an asymptomat... more The study compared the EMG changes and discomforts experienced by a symptomatic and an asymptomatic group of office workers when they were challenged by the physical stressors of increased typing speed and increased typing force. 21 female office workers were recruited in the Case Group and 20 in the Control Group. Each subject had to perform 20min of typing in
Work-related neck and upper limb disorders (WRNULD) are common problems among office workers who ... more Work-related neck and upper limb disorders (WRNULD) are common problems among office workers who use computers intensively and maintain prolonged static postures. These disorders have often been attributed to result from sustained muscle activity in the neck–shoulder musculature. The present study examined whether symptomatic subjects exhibited the same muscle activity patterns as asymptomatic controls when they performed a prolonged computer
Is exposure to non-music-related activities associated with playing-related musculoskeletal probl... more 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? Observational study using a questionnaire and physical measures. 859 instrumentalists aged 7 to 17 years from the School of Instrumental Music program. 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. 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. [Ranelli S, Straker L, Smith A (2014) Soreness during non-music activities is associated with playing-related musculoskeletal problems: an observational study of 731 child and adolescent intrumentalists.Journal of Physiotherapy60: 102-108].
ObjectivesResearchers investigating the effects of computer use and the development of musculoske... more ObjectivesResearchers investigating the effects of computer use and the development of musculoskeletal disorders have mainly focused on the effects of prolonged muscle loading associated with postures assumed during computer use in the adult population. The objective of this study was to investigate the effects of different forms of old and new information technology (IT) on muscle activity levels in a
Prolonged static posture has been identified as a major risk factor for work-related neck and upp... more Prolonged static posture has been identified as a major risk factor for work-related neck and upper limb disorders (WRNULD) in computer users. Previous research has mainly examined working postures in healthy pain-free individuals. The present study examined whether symptomatic subjects exhibited the same kinematic patterns as asymptomatic controls during a prolonged computer task. In a Case–Control comparison, female office workers
International Journal of Industrial Ergonomics - INT J IND ERGONOMIC, 2006
This paper argues for the systematic development and presentation of evidence-based guidelines fo... more This paper argues for the systematic development and presentation of evidence-based guidelines for appropriate use of computers by children. The currently available guidelines are characterised and a proposed conceptual model presented. Five principles are presented as a foundation to the guidelines. The paper concludes with a framework for the guidelines, key evidence for and against guidelines, and gaps in the available evidence, with the aim of facilitating further discussion.
Engaging in low levels of physical activity (PA) and accumulating prolonged periods of sedentary ... more Engaging in low levels of physical activity (PA) and accumulating prolonged periods of sedentary behavior (SB) during daily life have been associated with deleterious health outcomes. The objective of this study was to undertake an analysis of the way in which PA and SB were accumulated after bariatric surgery. Adults 12 to 18 months after laparoscopic adjustable gastric banding or 6 to 18 months after laparoscopic sleeve gastrectomy wore 2 activity monitors during the waking hours for 7 days. Anthropometric and demographic data were recorded. Data were available on 40 participants (30 females; median ± interquartile range: age 46 ± 16 years, time since surgery 14 ± 8 months, body mass index 36 ± 9 kg/m(2)). The proportion of waking hours spent in SB, light PA, moderate PA, and vigorous PA was 72% ± 12%, 22% ± 9%, 5% ± 3% and 0% ± 0%, respectively. Half of the time in SB was accumulated in uninterrupted bouts ≥ 30 minutes. Almost all PA was accumulated in bouts<10 minutes in duration. The median daily step count was 9108 ± 4360. The proportion of people who completed an average of ≥ 10,000 steps/d was similar to that reported in Western Australian adults (39% versus 32%; P = .35). Our sample spent>70% of time in SB, half of which was accumulated in uninterrupted bouts ≥ 30 minutes. Very little time was spent in moderate or vigorous PA (5%), and this was accumulated in short bouts (<10 minutes). Healthcare professionals should target not just overall time in SB and PA, but also aim to reduce prolonged periods of SB and increase sustained periods of PA.
Objective: This study aimed to determine the effects of active workstation designs on speed and e... more Objective: This study aimed to determine the effects of active workstation designs on speed and error during typing, mouse pointing, and combined type and mouse-use tasks. Background: Office ergonomics has focused on musculoskeletal disorder prevention; however, increasing computer-based work also increases health risks associated with inactivity. Workstations allowing computer users to walk or cycle while performing computer tasks have been shown to demand sufficient energy expenditure to result in significant health benefits. However the performance effects of being active while using a computer have not been documented. Method: Thirty office workers (16 female, 15 touch typists) performed standardized computer tasks in six workstation conditions: sitting, standing, walking at 1.6 km/h and 3.2 km/h, and cycling at 5 and 30 watts. Performance, perceived performance, and heart rate were measured. Results: Computer task performance was lower when walking and slightly lower when cycli...
Use of computers by children has increased rapidly, however few studies have addressed factors wh... more Use of computers by children has increased rapidly, however few studies have addressed factors which may reduce musculoskeletal stress during computer use by children. This study quantified the postural and muscle activity effects of providing forearm support when children used computers. Twelve male and 12 female children (10–12 years) who regularly used computers were recruited. Activities were completed using a
The Animal Fun program was designed to enhance the motor ability of young children by imitating t... more The Animal Fun program was designed to enhance the motor ability of young children by imitating the movements of animals in a fun, inclusive setting. The efficacy of this program was investigated through a randomized controlled trial using a multivariate nested cohort design. Pre-intervention scores were recorded for 511 children aged 4.83 years to 6.17 years (M=5.42 years, SD=3.58 months). Six control and six intervention schools were compared 6 months later following the intervention, and then again at 18 months after the initial testing when the children were in their first school year. Changes in motor performance were examined using the Bruininks-Oseretsky Test of Motor Proficiency short form. Data were analyzed using multi-level-mixed effects linear regression. A significant Condition×Time interaction was found, F(2,1219)=3.35, p=.035, demonstrating that only the intervention group showed an improvement in motor ability. A significant Sex×Time interaction was also found, F(2,1219)=3.84, p=.022, with boys improving over time, but not girls. These findings have important implications for the efficacy of early intervention of motor skills and understanding the differences in motor performance between boys and girls.
Head and neck posture is an important factor in neck pain related to computer use; however, the e... more 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.
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