Backback and computer use among children and related musculoskeletal disorders
These abstracts are from: Work. 2009;32(3)
Effect of backpack load placement on posture and spinal curvature in prepubescent children
From: Work. 2009;32(3):351-60
Parents, educators and researchers have expressed concern about the long term impacts of children carrying excessive loads in their backpacks on a daily basis. Although many researchers have investigated appropriate weight limits for children’s packs, little research has been conducted on the design of children’s backpacks. The purpose of this study was to evaluate the changes in children’s trunk forward lean, cranio-vertebral angle and spinal lordosis angle that occurred with high, medium and low load locations during standing and walking. Ten-year-old children (n = 15) completed a repeated measures designed study while carrying 15% of each child’s body weight in a typical backpack with only shoulder straps. A special instrumented backpack was designed that allowed the weight to be placed in the proper location and continuously measure changes in spinal curvature. Trunk forward lean and cranio-vertebral angle postures were captured on digital video at five intervals including: standing without a backpack prior to a 1000 m walk; standing with a backpack at the beginning and end of a 1000 m walk; and walking with a backpack at the beginning and end of a 1000 m walk. Results indicated that significant changes occurred in trunk forward lean and cranio-vertebral angle when the backpack was loaded to 15% body weight. The low load placement in the backpack produced fewer changes in cranio-vertebral angle from the initial standing baseline measure than the high and mid placements. When all measures were assessed collectively, there were fewer changes in spinal lordosis angle in the low load placement. These findings indicate that future backpack designs should place loads lower on the spine in order to minimize children’s postural adaptations.
Backpack load limit recommendation for middle school students based on physiological and psychophysical measurements
From: Work. 2009;32(3):339-50
The load of student’s backpacks has raised questions over the safety and health of schoolchildren everywhere. The purpose of this study is to use electromyography (EMG), posture evaluation, heart rate, and ratings of perceived exertion and perceptions of pain to find an acceptable backpack load limit for middle school students. Twenty middle school students aged 11 to 14 (10 female and 10 male) volunteered for the study. The subjects completed two tests, standing stationary and walking on a treadmill, where they carried 5% incremental loads from 0% body mass to 20% body mass. The study indicated that the Borg-CR10 ratings and trunk flexion angle for the walking trial indicated a possible load limit of 10% body mass due to the non-significant difference between 0 and 10% body mass and the significant difference between 10 and 15% body mass.
Computer use in school: Its effect on posture and discomfort in schoolchildren
From: Work. 2009;32(3):321-8
The aim of the study was to investigate the posture and musculoskeletal discomfort of secondary school students while working at computers in school. Students (n = 40) were observed while working at a computer during their designated computer class. The Rapid Upper Limb Assessment Tool was used to assess posture. A Body Discomfort Chart and Visual Analogue Scale were used to record the area(s) and intensity of musculoskeletal discomfort, if any, experienced by the students at the beginning and end of the computer class. None of the students’ posture was in the acceptable range (Action Level 1) according to Rapid Upper Limb Assessment Tool. The majority (65%) were in Action Level 2, 30% were in Action Level 3, and 5% were in Action Level 4. There was a statistically significant increase in reported discomfort from the beginning to the end of the computer class. Longer class length (80 minutes) did not result in greater reporting of discomfort than shorter class length (40 minutes).
A comparison of posture and muscle activity means and variation amongst young children, older children and young adults whilst working with computers
From: Work. 2009;32(3):311-20
Children and young adults are the most frequent users of computers. Whilst guidelines for adults have been based on research, available guidelines for children have had to assume children and adults are similar due to limited research evidence derived specifically from children. This study aimed to compare the posture and muscle activity of children with young adults. Thirty six adults aged 18-25 years, 24 children aged 10-12 years and 18 children aged 5-6 years participated in a series of laboratory studies. Upper body postures were measured using a 3D motion analysis system. Muscle activity of bilateral cervical erector spinae and upper trapezius muscles was assessed. Mean and variation were examined, the latter using both amplitude range and Exposure Variation Analysis matrix standard deviation. Mean postures assumed by children tended to show more spinal flexion and spinal asymmetry than adults. However children also tended to show more variation in posture and muscle activity. These findings suggest that whilst there may be differences in how children and adults use computers, basic principles of encouraging appropriate postures and variation should apply for both children and adults.
Computer-related posture and musculoskeletal discomfort in middle school students
From: Work. 2009;32(3):275-83
In recent years, there has been an increasing concern over the association between computer use and reports of discomfort, aches and pains in students. It is suggested that the physical set-up and individual styles of using interactive media has an influence over this discomfort. As children grow up, they will interact and use computers throughout most of their life. Healthy computing may be vital to preventing/reducing the incidence of discomfort/pain associated with interactive media. This research paper will describe a study, which has collected health and comfort data on the incidence and prevalence of self-reported computer-related musculoskeletal discomfort/pain among 6th and 7th grade students in three middle schools in New England. General base line data from this three-year study is reported
Why do children think they get discomfort related to daily activities?
From: Work. 2009;32(3):267-74
Children commonly report musculoskeletal discomfort related to different activities such as computer use, playing electronic games, watching TV, reading, and performing physical and hand intensive activities. Discomfort can result in disability and is a strong predictor of future discomfort in adulthood. Adult beliefs regarding discomfort can affect the level of disability and are modifiable. Children’s beliefs regarding discomfort could potentially be modified to minimise disability related to musculoskeletal disorders. The aim of this study was to describe children’s beliefs about why they experience musculoskeletal discomfort, both in general and related to specific activities. Eighty eight school children completed questionnaires on frequency and usual duration of nine activities, whether they had felt discomfort and what they believed was the cause of any discomfort in relation to those activities. The most common activity was TV watching, and most activities were performed for 1 hour or shorter. Bad posture and doing too much of a certain activity were the most common beliefs regarding reasons for discomfort. This study shows that children are developing beliefs that tend to reflect scientific knowledge about risk factors. These beliefs could be incorporated into preventative health interventions.
