Background: The level of activity in an individual can be the difference between health and illness. Physical inactivity can cause diseases such as osteoporosis and type-2 diabetes. It has been reported that children live an increasingly inactive life, with less than the recommended a total of 60 minutes daily for children and adolescents of 6-17 years of age. Objective: The objective was to compare two activity diaries and how the results correspond to measurements by an activity meter. Material and methods: This study included 12 children who each carried an activity meter for four days to measure Total Energy Expenditure. In parallel, they filled in two different activity diaries. In the diaries two different calculation methods were used, with a Physical Activity Ratio value or a Metabolic Equivalent of Task value which then was inserted into equations to calculate Total Energy Expenditure. Anthropometric measurements were obtained by use of a stadiometer, a caliper and a bioimpedance scale. Results: The results from the Physical Activity Ratio diary indicated a better match with the results from the activity meter. Conclusions: Between the two diaries significant difference in how the activities were estimated were found, where an overestimation could be seen in the diary that used the Metabolic Equivalent of Task. Differences could also be seen between the activity meter and both diaries, also here the difference were bigger with the Metabolic Equivalent of Task diary. The Physical Activity Ratio diary was better matched with the activity meter.

Fysisk aktivitet är en viktig del i alla människors liv och på senare år har flera tekniker utvecklats för att mäta just denna parameter. Detta har bidragit till en stor utveckling bland flertalet olika portabla tekniker, ofta i form av aktivitetsmätare, för att underlätta mätningar för alla inblandade. I samarbete med Energimetaboliska Laboratoriet (EML) på Akademiska sjukhuset i Uppsala studeras i denna studie kliniska aktivitetsmätare som används för monitorering av barn och unga vuxna. Syftet med studien är att få en djupare förståelse för de olika aktivitetsmätarnas modeller och fabrikat samt hur placeringar av dessa förhåller sig till varandra. Den parameter som jämfördes i studien var energiförbrukning som presenteras i kilokalorier (kcal). Jämförelsen gjordes mellan tre olika sorters aktivitetsmätare: ActiGraph GT9X Link som placerades runt handled, ActiGraph wGT3X-BT som placerades runt ankel samt Philips ActiCal som placerades runt både handled och ankel.Aktivitetsmätarna i denna studie mäter rörelse genom inbyggda accelerometrar. Accelerometrarna innehåller rörliga komponenter som förflyttas beroende på hur den som bär aktivitetsmätarna rör sig. Rörelserna omvandlas sedan till signaler som utlöser så kallade ”counts”. Counts är en storhet vars syfte är att registrera verkliga rörelser. För att erhålla counts så måste rörelsen antingen överstiga ett förutbestämt tröskelvärde eller låta de rörliga komponenterna genomföra en full cykel, exempelvis röra sig upp och sedan ned. Counts beräknas senare till bärarens energiförbrukning genom olika typer av algoritmer.I den empiriska studie som gjordes medverkade 13 deltagare som fick bära aktivitetsmätarna under ett helt dygn med start vid midnatt. Deltagarnas längd, vikt och ålder samlades in för att programmera aktivitetsmätarna enligt leverantörernas instruktioner. Extrahering av data skedde i tillverkarnas egna program ActiLife v6 13.1 och ActiCal v3.0 där beräkning av energiförbrukning skedde. När data var insamlad sammanställdes det i Microsoft Excel v16.72 för att enklare visualisera skillnader i energiförbrukning mellan deltagarna. Insamlade data jämfördes sedan statistiskt för att dra slutsatser om eventuella skillnader. Inga referensvärden användes i studien då aktivitetsmätarna endast jämfördes mot varandra.Resultaten visade tydliga skillnader mellan både fabrikat och placering beroende på vilka modeller som jämfördes. En relativt stor skillnad i energiförbrukning uppmättes mellan ActiGraph GT9X Link och wGT3X-BT där aktivitetsmätaren som placerades runt handleden uppmätte högre energiförbrukning för samtliga deltagare. En liknande skillnad uppmättes även vid jämförelse av ActiGraph GT9X Link och Phillips ActiCal placerad runt handled. Ingen statistisk skillnad kunde påvisas mellan ActiGraph wGT3X-BT och ActiCal, när de placerades runt ankeln. De båda placeringarna av ActiCal påvisade att dess tolkning av energiförbrukning ej skiljer sig åt särskilt mycket. / Background:Physical activity is a big part of everyone’s life and health. In recent years, the development of methods to monitor physical activity has increased drastically. Common parameters to measure are heart rate and respiratory rate but also physical movement. This is commonly measured with a wristwatch. Furthermore, there are several models made for clinical use, but the issue is that it is unknown how these activity monitors compare to each other. Aim:The aim of this study is to obtain a better understanding of the activity monitors ActiGraph GT9X Link, wGT3X-BT and Philips ActiCal for clinical use and how they compare to each other in regard to measuring energy expenditure. It also aims to investigate differences in monitor placement and how that affects the outcome. Method:An empirical study was made with 13 participants wearing the ActiGraph GT9X Link on the wrist, wGT3X-BT on the ankle and the Philips ActiCal on both places during a 24-hour period. The data collected was then analyzed to compare the monitors. Result:Differences were found between the two ActiGraph monitors as well as the ActiCal and ActiGraph GT9X Link placed on the wrist. The ActiGraph GT9X Link had overall the highest rate of energy expenditure. Furthermore, the ActiCal had the most similar results when comparing placement. Conclusion:The conclusion was that the ActiGraph GT9X Link is the most sensitive monitor and the ActiCal most reliable regarding placement.

Bibliographic identification Name and surname of the author: Mgr. Jakub Kokštejn Name of the dissertation: Physical activity of children with motor difficulties Workplace: Department of Sports Games Supervisor of the work: Doc. PaedDr. Rudolf Psotta, Ph.D. Year of presentation: 2011 Abstract Objective: Current knowledge of developmental disorders in motor skills of school children suggest potential negative impacts on the development of the personality of the child in the mental, social psychological and behavioural areas and also in the area of competence at school. Very little is known about how an insufficient level of motor skills of a child can limit his/her physical activity. This work was performed to discover whether developmentally determined motor deficit in children of older school age is a risk factor for lower physical activity (PA) and whether the attention of the child has a mediation function in the relationship between the level of motor skills and his/her physical activity. Methods: The research was based on analytical-descriptive examination of the motor skills of children, their physical activity in weekly regimes and the attention level, with subsequent comparison of children with a motor deficit (MD) and children without MD, through correlation analysis and analysis of the mediative...

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Children’s energy requirements may vary during school and summer camp days. To evaluate energy balance during these two periods, seventy-eight children (45% females, 8–10 years) living in Parma, Italy, were enrolled in this observational study. Participants completed a 3-day food diary and wore an activity tracker for three consecutive days during a school- and a summer camp-week to estimate energy intake (EI) and energy expenditure (TEE). Height and body weight were measured at the beginning of each period to define children’s weight status. BMI and EI (school: 1692 ± 265 kcal/day; summer camp: 1738 ± 262 kcal/day) were similar during both periods. Both physical activity and TEE (summer camp: 1948 ± 312; school: 1704 ± 263 kcal/day) were higher during summer camp compared to school time. Therefore, energy balance was more negative during summer camp (−209 ± 366 kcal/day) compared to school time (−12 ± 331 kcal/day). Similar results were observed when males and females were analyzed separately but, comparing the sexes, males had a higher TEE and a more negative energy balance than females, during both periods. The results strongly suggest that an accurate evaluation of children’s energy balance, that considers both diet and physical activity, is needed when planning adequate diets for different situations.

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Low back pain (LBP) remains the most prevalent and costly work-related disability worldwide and is directly associated with "physical" risk factors prevalent in manual material handling (MMH) tasks. Back-support exoskeletons (BSEs) are a promising ergonomic intervention to mitigate LBP risk, by reducing muscular exertion and spine loading. The purpose of this work was to help better understand both the "intended" and "unintended" consequences of BSE use on physical risk factors for LBP, as an essential prerequisite for the safe and effective implementation of this technology in actual workplaces. The first study assessed the effects of using two BSEs on objective and subjective responses during repetitive lifting involving symmetric and asymmetric postures. Wearing both BSEs significantly reduced peak levels of trunk extensor muscle activity and reduced energy expenditure. Such reductions, though, were more pronounced in the symmetric conditions and differed between the two BSEs tested. The second study quantified the assistive torque profiles of two passive BSEs using a computerized dynamometer, with both human subjects and a mannequin. Clear differences in torque magnitudes were evident between the BSEs, though both generated more assistive torques during flexion than extension. The third study estimated the effects of BSE use on lumbosacral compressive and shear forces during repetitive lifting using an optimization-based model. Using both BSEs reduced peak compression and anteroposterior shear forces, but these effects differed between tasks and BSE designs. Reductions in composite measures of trunk muscle activity did not correspond consistently with changes in spine forces when using a BSE. The fourth study quantified the effects of two passive BSEs on trunk stability and movement coordination during repetitive lifting. Some adverse effects on stability were evident for pelvis and thorax movements and coupling of these body segments, suggesting that caution is needed in selecting a BSE for a given MMH task. Overall, we found that the efficacy of BSEs is design- and task-specific. Important safety features of the exoskeletons were also identified, providing insights on their performance boundaries. Overall, the BSEs tested were more effective and safer in tasks closer to the mid-sagittal plane and with moderate degrees of trunk flexion. / Doctor of Philosophy / Low back pain (LBP) remains the most prevalent and costly work-related disability worldwide, and the risk of LBP is related to "physical" risk factors common in manual material handling (MMH) tasks. Back-support exoskeletons (BSEs) are a new ergonomic intervention that may reduce the risk of occupational LBP, by reducing muscular efforts and loads on the spine. For the safe use of BSEs, though, it is critical to better understand both the "intended" and "unintended" consequences of this emerging technology. In this dissertation, such consequences of BSE use were evaluated in the context of repetitive lifting tasks. The first study assessed the efficacy of two BSEs in terms of physical demands during repetitive lifting tasks involving a range of torso bending and twisting. Wearing both BSEs reduced the physical demands on back muscles and decreased energy consumption. Larger reductions, though, were observed in forward bending and such reductions differed between the two BSEs tested. The second study measured the amount of support provided by two BSEs using a new measurement method, which was examined for both human subjects and a mannequin. Clear differences in the BSE support were evident between the BSEs, and both devices generated more support during torso forward bending than returning upright. The third study estimated the effects of BSE use on low back loadings during repetitive lifting using a computational model. Using both BSEs reduced loads on the low back region, though such reductions were task-specific and depended on the BSE design. The fourth study quantified the effects of the BSE use on torso stability and movement patterns during repetitive lifting. Some adverse effects on stability were evident for lower and upper torso, suggesting that caution is needed in selecting a BSE for a given MMH task. Findings from this work show the potential benefits of BSEs for use in MMH tasks, yet such benefits can depend on the BSE design and the MMH task they are used for. Further, BSE use can lead to adverse effects, especially with tasks involving extreme working postures.