Accelerometer techniques for capturing human movement validated against direct observation: a scoping review.

INTRODUCTION: Accelerometers are devices commonly used to measure human physical activity and sedentary time. Accelerometer capabilities and analytical techniques have evolved rapidly, making it difficult for researchers to keep track of advances and best practices for data processing and analysis. OBJECTIVE: The objective of this scoping review is to determine the existing methods for analyzing accelerometer data for capturing human movement which have been validated against the criterion measure of direct observation. METHODS: This scoping review searched 14 academic and 5 grey databases. Two independent raters screened by title and abstract, then full text. Data were extracted using Microsoft Excel and checked by an independent reviewer. RESULTS: The search yielded 1039 papers and the final analysis included 115 papers. 71 unique accelerometer models were used across a total of 4217 participants. While all studies underwent validation from direct observation, most direct observation occurred live (55%) or using recordings (42%). Analysis techniques included machine learning approaches (22%), the use of existing cut-points (18%), ROC curves to determine cut-points (14%), and other strategies including regressions and non-machine learning algorithms (8%). DISCUSSION: Machine learning techniques are becoming more prevalent and are often used for activity identification. Cut-point methods are still frequently used. Activity intensity is the most assessed activity outcome; however, both the analyses and outcomes assessed vary by wear location. CONCLUSIONS: This scoping review provides a comprehensive overview of accelerometer analysis and validation techniques using direct observation and is a useful tool for researchers using accelerometers.

Physical Activity in Pediatric Inflammatory Bowel Disease: A Scoping Review.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic, systemic condition affecting the gastrointestinal tract. IBD can be severe and are associated with impairment in growth, school absences, abdominal pain, and fatigue. Physical activity (PA) could have an anti-inflammatory effect in addition to other benefits. It is important to address the possible risks, physiological effects of PA, and potential barriers, and facilitators for PA participation in pediatric IBD. However, potential barriers and facilitators to PA have yet to be adequately described. METHODS: We conducted a scoping review to map and describe the current literature on PA in pediatric IBD populations between 1980 and April 2022 using Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines for Scoping reviews. RESULTS: Nineteen articles were identified including 10 descriptive, 6 interventional, and 3 physiological responses to PA studies. Patients and healthy controls demonstrated similar responses to exercise. Barriers to participation were low self-esteem, body image, and active IBD symptoms. Facilitators included personal interest, activity with friends, and support from family. CONCLUSION: This review highlighted that PA participation may reduce in children with IBD-related symptoms. Short- and medium-term impacts of PA on immune modulation require further study; it is possible that regular PA does not negatively affect biomarkers of disease activity.

New Insights Into Accelerometer-Measured Habitual Physical Activity and Sedentary Time During Early Recovery in Pediatric Concussion.

PURPOSE: Concussion management is shifting away from a rest-is-best approach, as data now suggest that exercise-is-medicine for this mild brain injury. Despite this, we have limited data on habitual physical activity following concussion. Therefore, our objective was to quantify accelerometer-measured physical activity and sedentary time in children with concussion (within the first month of injury) and healthy controls. We hypothesized that children with concussion would be less active than their healthy peers. METHODS: We performed a secondary analysis of prospectively collected accelerometer data. Our sample included children with concussion (n = 60, 31 females) and historical controls (n = 60) matched for age, sex, and season of accelerometer wear. RESULTS: Children with concussion were significantly more sedentary than controls (mean difference [MD], 38.3 min/d, P = .006), and spent less time performing light physical activity (MD, -19.5 min/d, P = .008), moderate physical activity (MD, -9.8 min/d, P < .001), and vigorous physical activity (MD, -12.0 min/d, P < .001); these differences were observed from 8:00 AM to 9:00 PM. Sex-specific analyses identified that girls with concussion were less active and more sedentary than both boys with concussion (P = .010) and healthy girls (P < .010). CONCLUSION: There is an activity deficit observed within the first month of pediatric concussion. Physical activity guidelines should address this while considering sex effects.

The temporal and bi-directional relationship between physical activity and sleep in ambulatory children with cerebral palsy.

PURPOSE: Exploring the temporal and bi-directional relationship between device-based measures of physical activity and sleep in ambulatory children with cerebral palsy (CP). MATERIALS AND METHODS: 24-hour activity data were collected from children with CP (n = 51, 43% girls, mean age (range); 6.8 (3-12) years; Gross Motor Function Classification System levels I to III). Nocturnal sleep parameters and daily physical activity were measured for seven consecutive days and nights using ActiGraph GT3X accelerometers. Linear mixed models were constructed to explore the relationships between sleep and activity. RESULTS: Light and moderate-to-vigorous activity were negatively associated with sleep efficiency (SE) (resp. p = 0.04, p = 0.010) and total sleep time (TST) (resp. p = 0.007, p = 0.016) the following night. Sedentary time was positively associated with SE and TST the following night (resp. p = 0.014, p = 0.004). SE and TST were positively associated with sedentary time (resp. p = 0.011, p = 0.001) and negatively with moderate-to-vigorous physical activity (resp. p < 0.001, p = 0.002) the following day. Total bedtime and TST were negatively associated with light physical activity (resp. p = 0.046, p = 0.004) the following day. CONCLUSIONS: The findings from this study suggest that ambulatory children with CP may not sleep better after physical activity, and vice versa, indicating that the relationship is complex and needs further investigation.

The use of device-based accelerometry is a feasible method to measure 24-hour activity patterns with sleep and physical activity in ambulatory children with cerebral palsy.The relationships between sleep and physical activity in children with cerebral palsy are not as expected based on patterns shown in peers with typical development.Interventions for sleep in children with cerebral palsy require a holistic approach, focusing on daily physical activity patterns and relevant child- and contextual factors.

A Pilot Study of Exercise Training for Children and Adolescents With Inflammatory Bowel Disease: An Evaluation of Feasibility, Safety, Satisfaction, and Efficacy.

BACKGROUND: Children with inflammatory bowel disease (IBD) experience extraintestinal side effects including altered body composition, impaired muscle strength, and aerobic capacity. Exercise training may remedy these issues. PURPOSE: To assess the feasibility, safety, participant satisfaction, and efficacy of a training program for youth with IBD. METHODS: Children with IBD completed 16 weeks of training (2 supervised + 1 home sessions per week). Feasibility was assessed by tracking recruitment, adherence, and compliance rates. Safety was assessed by tracking symptoms and adverse events. Posttraining interviews gauged satisfaction. Circulating inflammatory markers, body composition, muscle strength, aerobic fitness, and habitual physical activity were measured at baseline, midtraining (8 wk), and posttraining. RESULTS: Eleven youth were recruited and 10 completed the study. Participants adhered to 28 (1) of 32 prescribed supervised sessions and 8 (4) of 16 prescribed home sessions. There were no adverse events, and overall feedback on training was positive. Posttraining, we observed an increase in lean mass (+2.4 [1.1] kg), bone density (+0.0124 [0.015] g·cm-2), aerobic fitness (+2.8 [5.7] mL·kg LM-1· min-1), and vigorous physical activity levels (+13.09 [8.95] min·h-1) but no change in inflammation or muscle strength. CONCLUSION: Supervised exercise training is feasible, safe, and effective for youth with IBD and should be encouraged.

Accelerometer-measured physical activity, sedentary behavior, and sleep in children with cerebral palsy and their adherence to the 24-hour activity guidelines.

AIM: To measure and describe the 24-hour activities (i.e. physical activity, sedentary behavior, and sleep) and to examine adherence to the 24-hour activity guidelines among children with cerebral palsy (CP) using actigraphy. METHOD: Children's 24-hour activities were recorded over 7 days using hip- and wrist-worn ActiGraph wGT3X-BT accelerometers. RESULTS: In total, 362 days and 340 nights from 54 children with CP (Gross Motor Function Classification System [GMFCS] levels I-III; 44% females; median age [range] 6 years 6 months [3-12 years]) were included. Mean (SD) daily wear time was 746.2 (48.9) minutes, of which children spent on average 33.8% in light physical activity (251.6 [58.7] minutes per day), 5.2% in moderate-to-vigorous physical activity (38.5 [20.1] minutes per day), and the remaining 61.1% being sedentary (456.1 [80.4] minutes per day). Physical activity decreased while sedentary behavior increased with increasing GMFCS level. In total, 13% of all children met the physical activity recommendations, and 35% met the age-appropriate sleep duration recommendation. The proportion of children meeting the combined 24-hour guidelines for physical activity and sleep was low (5.9%), especially in those classified in GMFCS level III (0%). INTERPRETATION: The observed low 24-hour guideline adherence rates emphasize the importance of considering the entire continuum of movement behaviors in the care of children with CP, in efforts to promote healthy lifestyle behaviors and prevent negative health outcomes.

Does Sleep Quality Influence Recovery Outcomes After Postconcussive Injury in Children and Adolescents?

OBJECTIVE: To determine whether objective parameters of sleep quality differ throughout recovery between children and adolescents who experienced an early return to school (RTS) and those who had a delayed RTS or did not return at all during the study period. SETTING: Sleep parameters reflective of sleep quality were evaluated in participants' natural sleeping habitat throughout 9 weeks postinjury. PARTICIPANTS: Ninety-four children and adolescents (aged 5-18 years) with diagnosed concussion. DESIGN: Prospective cohort. Participants followed RTS protocols. MAIN MEASURES: Actigraphy-derived estimates of total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), average arousal length (AAL), and number of arousals (NOAs) per hour were assessed. The length of time from injury until RTS was determined for each participant. Participants were categorized into an early RTS or delayed RTS group based on their time to RTS. RESULTS: Both TST and SE were significantly greater in the early RTS group. WASO duration, AAL, and NOAs were significantly greater in the delayed RTS group. Differences between RTS groups were most apparent during weeks 1 to 5 postinjury. CONCLUSIONS AND CLINICAL IMPLICATIONS: Participants who returned to school earlier had significantly better objective sleep quality than participants who experienced a delayed RTS. This study provides evidence in support of a relationship between sleep quality and time to RTS in children and adolescents with concussion. Considering early monitoring of sleep, education regarding sleep hygiene, and access to age-appropriate sleep interventions may be helpful in pediatric concussion recovery.

Exploring the relationship between resting-state intra-network connectivity and accelerometer-measured physical activity in pediatric concussion: a cohort study.

Our objective was to explore the association between resting-state functional connectivity and accelerometer-measured physical activity in pediatric concussion. Fourteen children with concussion (aged 14.54 ± 2.39 years, 8 female) were included in this secondary data analysis of a larger study. Participants had neuroimaging at 15.3 ± 6.7 days postinjury and subsequently a mean of 11.1 ± 5.0 days of accelerometer data. Intra-network connectivity of the default mode network (DMN), sensorimotor network (SMN), salience network (SN), and frontoparietal network (FPN) was computed using resting-state MRI. We found that, per general linear models (GLMs), only intra-network connectivity of the DMN was associated with physical activity levels. More specifically, increased intra-network connectivity of the DMN was significantly associated with higher levels of subsequent accelerometer-measured light physical activity (LPA; F(2, 11) = 7.053, p = 0.011, Ra2 = 0.562; ß = 0.469), moderate physical activity (MPA; F(2, 11) = 6.159, p = 0.016, Ra2 = 0.528; ß = 0.725), and vigorous physical activity (VPA; F(2, 11) = 10.855, p = 0.002, Ra2 = 0.664; ß = 0.792). Intra-network connectivity of the DMN did not significantly predict sedentary time. Therefore, these preliminary findings suggest that there is a positive association between the intra-network connectivity of the DMN and device-measured physical activity in children with concussion.

Correlates of Moderate-to-Vigorous Physical Activity in Children With Physical Illness and Physical-Mental Multimorbidity.

This study measured physical activity (PA) and explored its correlates among children with multimorbidity (co-occurring chronic physical and mental illness; MM) versus those with chronic physical illness only (PI). This study used baseline data from the Multimorbidity in Children and Youth Across the Life Course (MY LIFE) study, an on-going cohort study following 263 children with a PI 2 to 16 years of age (mean age: 9.8 years, SD = 4.0; 47.7% female). PA was measured using accelerometry, and demographic and psychosocial variables were collected using questionnaires. Of the 55 children with MM and the 85 with PI with valid accelerometer data, 38.1% and 41.2%, respectively, met average daily PA guidelines. Correlates of moderate-to-physical PA (MVPA) among children with MM were age, ρ(53) = -0.45, p = .001, body mass index (BMI), ρ(48) = -0.28, p = .04, self-perceived behavioral conduct, ρ(24) = -0.45, p = .02, physical health-related quality of life, ρ(51) = 0.56, p < .001, and peer support, ρ(52) = 0.27, p = .04. Correlates of MVPA among children with PI were age, ρ(83) = -0.40, p < .001, sex, ρ(83) = -0.26, p = .01, self-perceived social competence, ρ(31) = 0.42, p = .02, self-perceived athletic competence, ρ(31) = 0.48, p = .005, physical health-related quality of life, ρ(83) = 0.34, p = .001, participation in community sport, ρ(31) = 0.41, p = .02, and family functioning, ρ(83) = 0.26, p = .02. These results demonstrate that children with PI and MM are insufficiently active and their PA is correlated with demographic and psychosocial factors.

Deriving Normative Data on 24-Hour Ambulatory Blood Pressure Monitoring for South Asian Children (ASHA): A Clinical Research Protocol.

BACKGROUND: The global prevalence of hypertension in children and adolescents has increased over the past 2 decades and is the strongest predictor of adult hypertension. South Asians have an increased prevalence of metabolic syndrome associated risk factors including abdominal obesity, diabetes, and hypertension. All these factors contribute to their increased cardiovascular disease burden. Accurate and early identification of hypertension in South Asian children is a necessary aspect of cardiovascular disease prevention. Ambulatory blood pressure monitoring (ABPM) is considered the gold-standard for pediatric blood pressure (BP) measurement. However, its utilization is limited due to the lack of validated normative reference data in diverse, multiethnic pediatric populations. OBJECTIVE: The primary objective is to establish normative height-sex and age-sex-specific reference values for 24-h ABPM measurements among South Asian children and adolescents (aged 5-17 years) in Ontario and British Columbia, Canada. Secondary objectives are to evaluate differences in ABPM measurements by body mass index classification, to compare our normative data against pre-existing data from German and Hong Kong cohorts, and to evaluate relationships between habitual movement behaviors, diet quality, and ABPM measurements. DESIGN: Cross-sectional study, quasi-representative sample. SETTING: Participants will be recruited from schools, community centers, and places of worship in Southern Ontario (Greater Toronto and Hamilton area, including the Peel Region) and Greater Vancouver, British Columbia. PARTICIPANTS: We aim to recruit 2113 nonoverweight children (aged 5-17 years) for the primary objective. We aim to recruit an additional 633 overweight or obese children to address the secondary objectives. MEASUREMENTS: Ambulatory BP monitoring measurements will be obtained using Spacelabs 90217 ABPM devices, which are validated for pediatric use. The ActiGraph GT3X-BT accelerometer, which has also been validated for pediatric use, will be used to obtain movement behavior data. METHODS: Following recruitment, eligible children will be fitted with 24-h ABPM and physical activity monitors. Body anthropometrics and questionnaire data regarding medical and family history, medications, diet, physical activity, and substance use will be collected. Ambulatory BP monitoring data will be used to develop height-sex- and age-sex-specific normative reference values for South Asian children. Secondary objectives include evaluating differences in ABPM measures between normal weight, overweight and obese children; and comparing our South Asian ABPM data to existing German and Hong Kong data. We will also use compositional data analysis to evaluate associations between a child's habitual movement behaviors and ABPM measures. LIMITATIONS: Bloodwork will not be performed to facilitate recruitment. A non-South Asian comparator cohort will not be included due to feasibility concerns. Using a convenience sampling approach introduces the potential for selection bias. CONCLUSIONS: Ambulatory BP monitoring is a valuable tool for the identification and follow-up of pediatric hypertension and overcomes many of the limitations of office-based BP measurement. The development of normative ABPM data specific to South Asian children will increase the accuracy of BP measurement and hypertension identification in this at-risk population, providing an additional strategy for primary prevention of cardiovascular disease.

CONTEXTE: La prévalence mondiale de l'hypertension chez les enfants et les adolescents a augmenté au cours des deux dernières décennies et constitue le plus important facteur prédictif de l'hypertension chez les adultes. Le syndrome métabolique associé aux facteurs de risque que sont l'obésité abdominale, le diabète et l'hypertension est plus prévalent chez les personnes d'origine sud-asiatique. Tous ces facteurs contribuent à une charge de morbidité cardiovasculaire accrue pour ces personnes. Le dépistage précis et précoce de l'hypertension chez les enfants d'Asie du Sud est un aspect incontournable de la prévention des maladies cardiovasculaires. Le monitoring ambulatoire de la pression artérielle (MAPA) est considéré comme la norme pour la mesure de la pression artérielle chez les enfants. Son utilization est toutefois limitée en raison de l'absence de références normatives validées dans des populations pédiatriques diversifiées et multiethniques. OBJECTIFS: L'objectif principal est d'établir des valeurs de référence normatives taille-sexe et âge-sexe pour les mesures de MAPA sur 24 heures chez les enfants et les adolescents d'origine sud-asiatique (âgés de 5-17 ans) de l'Ontario et de Colombie-Britannique (Canada). Les objectifs secondaires sont : 1) d'évaluer les différences dans les mesures de MAPA selon une classification basée sur l'indice de masse corporelle; 2) de comparer nos données normatives aux données préexistantes tirées de cohortes d'Allemagne et de Hong Kong, et 3) d'évaluer les relations entre les comportements actifs habituels, la qualité de l'alimentation et les mesures de MAPA. TYPE D'ÉTUDE: Étude transversale avec échantillon quasi représentatif. CADRE: Les participants seront recrutés dans des écoles, des centers communautaires et des lieux de culte du sud de l'Ontario (région du Grand Toronto et de Hamilton, y compris la région de Peel) et du Grand Vancouver en Colombie-Britannique. SUJETS: Nous souhaitons recruter 2113 enfants (5 à 17 ans) ne présentant pas de surpoids pour l'objectif principal. Et 633 enfants en surpoids ou obèses pour les objectifs secondaires. MESURES: Les mesures de MAPA seront obtenues à l'aide d'appareils Spacelabs 90217 validés pour un usage pédiatrique. L'accéléromètre ActiGraph GT3X-BT, également validé pour un usage pédiatrique, sera utilisé pour colliger des données sur le comportement actif. MÉTHODOLOGIE: Après le recrutement, les enfants admissibles seront équipés d'un appareil de MAPA pour 24 heures et de moniteurs d'activité physique. Les caractéristiques anthropométriques et les données d'un questionnaire portant sur les antécédents médicaux et familiaux, la médication, l'alimentation, l'activité physique et la consommation de substances seront recueillies. Les données de MAPA seront utilisées pour établir des valeurs de référence normatives taille-sexe et âge-sexe pour les enfants d'Asie du Sud. Les objectifs secondaires comprennent l'évaluation des différences dans les mesures de MAPA selon que les enfants ont un poids normal, un surpoids ou sont obèses, et la comparaison de nos données de MAPA pour des enfants d'Asie du Sud avec les données existantes en Allemagne et à Hong Kong. Nous procèderons également à l'analyze de composition des données afin d'évaluer les relations entre les comportements actifs habituels de l'enfant et les mesures de MAPA. LIMITES: Pour faciliter le recrutement, les analyses sanguines ne seront pas effectuées. Aucune cohorte de comparaison constituée de sujets non originaires d'Asie du Sud ne sera incluse en raison de problèmes de faisabilité. L'emploi d'une approche d'échantillonnage de commodité introduit un possible biais de sélection. CONCLUSION: Le MAPA est un outil précieux pour le dépistage et le suivi de l'hypertension pédiatrique et elle permet de surmonter plusieurs des limites de la mesure de la PA en cabinet. L'établissement de références normatives de MAPA spécifiques aux enfants d'Asie du Sud permettra d'accroître la précision de la mesure de la PA et le dépistage de l'hypertension dans cette population à risque, fournissant ainsi une stratégie supplémentaire pour la prévention primaire des maladies cardiovasculaires.

The Effects of Exercise Serum From Prepubertal Girls and Women on In Vitro Myoblast and Osteoblast Proliferation and Differentiation.

PURPOSE: In girls and women, the authors studied the effects of an acute bout of low-impact, moderate-intensity exercise serum on myoblast and osteoblast proliferation in vitro. METHODS: A total of 12 pre/early pubertal girls (8-10 y old) and 12 women (20-30 y old) cycled at 60% VO2max for 1 hour followed by 1-hour recovery. Blood samples were collected at rest, mid-exercise, end of exercise, mid-recovery, and end of recovery. C2C12 myoblasts and MC3T3E1 osteoblasts were incubated with serum from each time point for 1 hour, then monitored for 24 hours (myoblasts) or 36 hours (osteoblasts) to examine proliferation. Cells were also monitored for 6 days (myoblasts) to examine myotube formation and 21 days (osteoblasts) to examine mineralization. RESULTS: Exercise did not affect myoblast or osteoblast proliferation. Girls exhibited lower cell proliferation relative to women at end of exercise (osteoblasts, P = .041; myoblasts, P = .029) and mid-recovery (osteoblasts, P = .010). Mineralization was lower at end of recovery relative to rest (P = .014) in both girls and women. Myotube formation was not affected by exercise or group. CONCLUSION: The systemic environment following one acute bout of low-impact moderate-intensity exercise in girls and women does not elicit osteoblast or myoblast activity in vitro. Differences in myoblast and osteoblast proliferation between girls and women may be influenced by maturation.

Grip strength is lower in adults born with extremely low birth weight compared to term-born controls.

BACKGROUND: Grip strength predicts long-term morbidity and mortality in adults. We compared grip strength in adults born with extremely low birth weight (ELBW; under 1 kg) and a normal birth weight control group (NBW) and describe change in grip strength over a 10-year period in a longitudinal cohort study of preterm birth. METHODS: Grip strength, body composition, and device-measured physical activity were assessed in 95 mature adults (MA) born ELBW (age 31.6 (1.6) mean (SD) years, 59 females) and 88 born NBW (age 31.9 (1.4) years, 52 females). Regression models were used to examine the effect of perinatal factors, body composition, physical activity, and physical self-efficacy on grip strength. RESULTS: Grip strength was lower in MA born ELBW compared to NBW (31.8 (10.0) vs. 39.8 (11.2) kg; p < 0.001). Birth weight group was associated with grip strength independent of sex, height, and lean mass index, but device-measured physical activity was not. The change in grip strength from mid-20s to MA was similar in ELBW and NBW participants. DISCUSSION: Grip strength in MA born ELBW is low and is similar to a reference group 25-30 years older, suggesting higher risk for cardiovascular and all-cause mortality. IMPACT: Adults born extremely preterm have reduced grip strength compared to control participants born at full term. Reduced grip strength is a predictor of frailty and increased cardiovascular disease risk. Change in grip strength from age in mid-20s to mid-30s is similar in those born preterm and full-term-born controls. Grip strength is related to lean mass and not to device-measured physical activity-and correlates of grip strength are similar in those born preterm and term-born controls. Grip strength is a simple measure that may provide information about the health of adults born preterm.

Physical activity and sedentary behaviour in children with spina bifida.

AIM: To describe active and sedentary time in children with spina bifida and to compare their physical activity on weekdays versus weekends. METHOD: In this exploratory cross-sectional study, data from 13 Canadian and 22 Dutch children with spina bifida (14 females, 21 males; mean age 10y 11mo, standard deviation [SD] 3y 6mo, range 5y 6mo-18y; Hoffer classification distribution: community [n=28], household [n=3], non-functional [n=3], and non-ambulator [n=1]) were analysed. Objective measures of physical activity and sedentary behaviour were obtained by using ActiGraph or Actiheart activity monitors. Data for the participants wearing the ActiGraph were compared with age- and sex-matched controls that were developing typically using independent-samples t-tests. Activity data collected on weekdays was compared to those on weekends. RESULTS: ActiGraph data demonstrated children with spina bifida spent more time sedentary (mean [SD] 49.5min/h [5.78]) and less time in moderate to vigorous physical activity (mean [SD] 2.33min/h [1.61]) compared with the typically developing group (mean [SD] 41.0min/h [5.76] and 5.46min/h [2.13], p=0.001 and p<0.001 respectively). For both ActiGraph- and Actiheart-derived data, physical activity and sedentary time were not significantly different between weekdays and weekends. INTERPRETATION: Children with spina bifida have reduced levels of physical activity and increased sedentary behaviour, with no statistical differences seen between weekdays and weekends. Several methodological issues related to activity monitoring warrant consideration when choosing the appropriate method to quantify physical activity and sedentary behaviour. WHAT THIS PAPER ADDS: Reduced levels of physical activity and sedentary time were quantified in children with spina bifida. Objective quantification of physical behaviour in ambulatory and non-ambulatory school-aged children with spina bifida is possible.

ACTIVIDAD FÍSICA Y COMPORTAMIENTO SEDENTARIO EN NIÑOS CON ESPINA BÍFIDA: OBJETIVO: Describir el tiempo activo y sedentario en niños con espina bífida y comparar su actividad física entre semana y fines de semana. MÉTODO: En este estudio exploratorio de corte transversal, datos de 13 niños canadienses y 22 holandeses con espina bífida (14 mujeres, 21 varones; edad media 10 años 11 meses, desviación estándar [DE] 3 años 6 meses, rango 5 años 6 meses - 18 años; se analizaron en base a la distribución basada en la clasificación de Hoffer: comunidad [n = 28], hogar [n = 3], no funcional [n = 3] y no ambulatorios [n = 1]). Se obtuvieron medidas objetivas de actividad física y comportamiento sedentario mediante el uso de monitores de actividad ActiGraph o Actiheart. Los datos de los participantes que usaban el ActiGraph se compararon con los niños con desarrollo típicos como controles, apareados por edad y sexo usando pruebas t de muestras independientes. Los datos de actividad recopilados durante la semana se compararon con los de los fines de semana. RESULTADOS: Los datos de ActiGraph demostraron que los niños con espina bífida pasaron más tiempo sedentarios (media [DE] 49,5min / h [5,78]) y menos tiempo en actividades físicas moderadas a intensas (media [DE] 2,33min / h [1,61]) en comparación con el grupo control (media [DE] 41,0min / h [5,76] y 5,46min / h [2,13], p = 0,001 y p <0,001 respectivamente). Tanto para los datos derivados de ActiGraph como de Actiheart, la actividad física y el tiempo sedentario no fueron significativamente diferentes entre semana y fines de semana. INTERPRETACIÓN: Los niños con espina bífida tienen niveles reducidos de actividad física y un mayor comportamiento sedentario, sin diferencias estadísticas observadas entre semana y fines de semana. Al elegir un método apropiado para cuantificar la actividad física y el comportamiento sedentario se deben considerar varios problemas metodológicos relacionados con el monitoreo de la actividad en esta población.

ATIVIDADE FÍSICA E COMPORTAMENTO SEDENTÁRIO EM CRIANÇAS COM ESPINHA BÍFIDA: OBJETIVO: Descrever o tempo ativo e sedentário de crianças com espinha bífida e comparar sua atividade física durante a semana versus fins de semana. MÉTODO: Neste estudo exploratório transversal, dados de 13 crianças canadenses e 22 crianças holandesas com espinha bífida (14 do sexo feminino, 21 do sexo masculino; médida de idade 10a 11m, desvio padrão [DP] 3a 6m, variação 5a 6m-18a; Distribuição da classificação de Hoffer: comunidade [n=28], domiciliar [n=3], não funcional [n=3], e não ambulatório [n=1]) foram analisados. Medidas objetivas de atividade física e comportamento sedentário foram obtidas por meio de monitores de atividade ActiGraph ou Actiheart. Dados para os participantes que usaram ActiGraph foram comparados com controles pareados por idade e sexo que tinha desenvolvimento típico usando testes t para amostras independentes. Dados de atividade coletados durante a semana foram comparados com os dados de finais de semana. RESULTADOS: Os dados do ActiGraph demonstraram que crianças com espinha bífida passaram mais tempo sedentário (média [DP] 49,5min/h [5,78]) e menos tempo em atividade física vigorosa (média [DP] 2,33min/h [1,61]) comparados com o grupo com desenvolvimento típico (média [DP] 41,0min/h [5,76] e 5,46min/h [2,13], p=0,001 and p<0,001 respectivamente). Para os dados derivados do ActiGraph- e Actiheart, a atividade física e o tempo sedentário não foram significativamente diferentes comparando os dias da semana com os fins de semana. INTERPRETAÇÃO: Crianças com espinha bífida têm níveis reduzidos de atividade física e comportamento sedentário aumentado, sem diferenças estatísticas quando comparados os dias da semana. Várias questões metodológicas relacionadas ao monitoramento de atividades indicam necessidade de refletir quanto à escolha do método apropriado para quantificar a ativiade física e comportamento sedentário.

Focus on Risk Factors for Cardiometabolic Disease in Cerebral Palsy: Toward a Core Set of Outcome Measurement Instruments.

OBJECTIVE: To identify existing outcome measurement instruments (OMIs) assessing risk factors for cardiometabolic disease in adolescents and adults with cerebral palsy (CP) reported on in the literature or used in the field. DATA SOURCES: The COnsensus-based Standards for the selection of health Measurement Instruments database of systematic reviews and 4 electronic databases (Embase, MEDLINE/Ovid, MEDLINE/Pubmed, PsychINFO) were searched up to June 19, 2017, that yielded 2594 articles. Experts in the field were consulted to identify any additional OMIs. STUDY SELECTION: Two reviewers independently applied inclusion criteria to select eligible studies using or evaluating measurement properties of OMIs assessing 1 of 8 outcomes: cardiorespiratory endurance, body size, body composition, physical behavior, sleep, nutrition, blood pressure, and blood lipids and glucose. Studies with an experimental or observational design including ≥10 adolescents or adults with CP were included. DATA EXTRACTION: One reviewer extracted data that were summarized for study and sample characteristics, outcomes, OMIs used, and if applicable data on measurement properties. Two reviewers rated the methodological quality and the quality of the OMIs. Feasibility for clinical practice and research was rated by experts in the field. DATA SYNTHESIS: Ninety OMIs were identified from 56 included articles and by the experts. Seventy OMIs pertained to cardiorespiratory endurance, body size, body composition, and physical behavior, whereas only 5 were identified for sleep and nutrition. Overall synthesis revealed that there is moderate to poor evidence for good quality of OMIs in this population. Based on feasibility for clinical practice, experts agreed on a single OMI per outcome (and 2 for cardiorespiratory endurance) to be included in a core set. CONCLUSION: Despite the range of available OMIs to assess risk factors for cardiometabolic disease in adolescents and adults with CP, evidence of good quality is often lacking. Nonetheless, a preliminary core set of 9 OMIs was systematically developed.

Differences in cardiovascular health in ambulatory persons with cerebral palsy.

OBJECTIVE: To compare cardiovascular health variables and physical activity levels of adolescents and adults with cerebral palsy who are Gross Motor Func-tion Classification System (GMFCS) levels I and II. METHODS: Eleven adolescents (mean age 13.1 (standard deviation (SD) 2.1) years) and 14 adults (mean age 31.7 (SD 10.4) years)) with cerebral palsy were included, grouped by their GMFCS level (level I (n = 12); level II (n = 13)). Assessments of cardiovascular health, body composition and physical activity levels were performed. Cardiovascular variables included resting blood pressure and carotid artery intima media thickness. Body composition included height, weight, body mass index, and waist circumference. Physical activity was measured using accelerometry. RESULTS: Adjusting for age between GMFCS levels (GMFCS I mean 17.3 (SD 5.2); GMFCS II mean 29.3 (SD 14.1) years, p = 0.011), significant differences were evident for moderate-to-vigorous physical activity per day (GMFCS I median 45.8 (interquartile range (IQR) 32.4-75.1); GMFCS II median 16.4 (IQR 13.0, 25.0) min/day, p = 0.011), height (GMFCS I mean 1.63 (SD 0.14); GMFCS II mean 1.56 (SD 0.12) m, p = 0.010), mean arterial pressure (GMFCS I mean 84.6 (SD 7.8); GMFCS II mean 89.4 (SD 8.5) mmHg, p = 0.030), and carotid artery intima media thickness (GMFCS I mean 0.431 (SD 0.06); GMFCS II mean 0.489 (SD 0.04), p = 0.026). CONCLUSION: Individuals with cerebral palsy who were GMFCS level I had lower mean arterial pressure, thinner carotid artery intima media thickness, and engaged in a greater amount of moderate-to-vigorous physical activity per day than those who were GMFCS level II. Clinicians should acknowledge that ambulatory individuals with cerebral palsy could have differing cardiovascular health profiles and should monitor these cardiovascular variables and discuss physical activity during healthcare visits, regardless of age.

Exploring Accelerometer Versus Self-Report Sleep Assessment in Youth With Concussion.

This study examines accelerometer-based and self-report assessment of sleep disturbance from a larger prospective cohort of youth 5 to 18 years of age with postconcussive injury. Twenty-one participants with self-reported sleep disturbance were evaluated using accelerometers. Participants completed the Pittsburgh Sleep Quality Index (PSQI) every 48 hours and also measured sleep via accelerometry. Correlations were conducted matching PSQI scores to accelerometry assessment. PSQI scores were significantly correlated only with "average number of awakenings" (r = -0.21; P = .049). Accelerometer-measured mean (standard deviation) sleep efficiency was 79.9% (5.20%), with normal sleep defined as >85%. The mean (standard deviation) PSQI global score was 10.5 (3.78) out of 21, where scores of >5 indicate subjective insomnia. Results suggest the PSQI and accelerometers may be measuring different attributes of sleep. Both may be needed as actual sleep is important but so is perception of good sleep. These findings call for further validity testing of objective sleep assessment measures and commonly used self-report tools.

Thermoregulation in boys and men exercising at the same heat production per unit body mass.

PURPOSE: Child-adult thermoregulatory comparisons may be biased by differences in metabolic heat production ([Formula: see text]). We compared thermoregulatory responses of boys and men exercising at two intensities prescribed to elicit either a fixed [Formula: see text] per unit body mass (BM) or a fixed absolute [Formula: see text]. METHODS: Ten boys (10-12 years) and 10 men (19-25 years) performed 4 × 20-min cycling at a fixed [Formula: see text] per BM (W kg(-1)) at 35 °C and 35 % relative humidity (MENREL). Men also cycled (MENABS) at the same absolute [Formula: see text] (in W) as the boys. RESULTS: [Formula: see text] was lower in boys compared with MENREL, but similar to MENABS (mean ± SD, 233.6 ± 38.4, 396.5 ± 72.3, 233.6 ± 34.1 W, respectively, P < 0.001). Conversely, [Formula: see text] per unit BM was similar between boys and MENREL, and lower in MENABS (5.7 ± 1.0, 5.6 ± 0.8 and 3.3 ± 0.3 W kg(-1), respectively; P < 0.001). The change in rectal temperature was similar between boys and MENREL (0.6 ± 0.2 vs. 0.7 ± 0.2 °C, P = 0.92) but was lower in MENABS (0.3 ± 0.2 °C, P = 0.004). Sweat volume was lower in boys compared to MENABS (500 ± 173 vs. 710 ± 150 mL; P = 0.041), despite the same evaporative heat balance requirement (E req) (199.1 ± 34.2 vs. 201.0 ± 32.7 W, P = 0.87). CONCLUSION: Boys and men demonstrated similar thermoregulatory responses to 80 min of exercise in the heat performed at a fixed [Formula: see text] per unit BM. Sweat volume was lower in boys compared to men, despite similarities in absolute [Formula: see text] and E req.

The Effect of Postexercise Milk Protein Intake on Rehydration of Children.

PURPOSE: In adults, rehydration after exercise in the heat can be enhanced with a protein-containing beverage; however, whether this applies to children remains unknown. This study examined the effect of milk protein intake on postexercise rehydration in children. METHOD: Fifteen children (10-12 years) performed three exercise trials in the heat (34.4 ± 0.2 °C, 47.9 ± 1.1% relative humidity). In a randomized, counterbalanced crossover design, participants consumed iso-caloric and electrolyte-matched beverages containing 0 g (CONT), 0.76 g (Lo-PRO) or 1.5 g (Hi-PRO) of milk protein/100 mL in a volume equal to 150% of their body mass (BM) loss during exercise. BM was then assessed over 4 h of recovery. RESULTS: Fluid balance demonstrated a significant condition × time interaction (p = .012) throughout recovery; Hi-PRO was less negative than CONT at 2 hr (p = .01) and tended to be less negative at 3 h (p = .07). Compared with CONT, beverage retention was enhanced by Hi-PRO at 2 h (p < .05). CONCLUSION: A postexercise beverage containing milk protein can favorably affect fluid retention in children. Further research is needed to determine the optimal volume and composition of a rehydration beverage for complete restoration of fluid balance.

Effects of acute exercise on circulating endothelial and progenitor cells in children and adolescents with juvenile idiopathic arthritis and healthy controls: a pilot study.

BACKGROUND: Youth with juvenile idiopathic arthritis (JIA) may be at risk of poor cardiovascular health. Circulating endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are markers of cardiovascular repair and damage, respectively, and respond to exercise. The objectives of this study were to compare resting levels of EPCs and CECs in JIA and controls, and to assess the effects of distinct types of exercise on EPCs and CECs in JIA and controls. METHODS: Seven youth with JIA and six controls completed 3 visits. First, aerobic fitness was assessed. Participants then performed either moderate intensity, continuous exercise (MICE) or high intensity, intermittent exercise (HIIE) on separate days. Blood samples were collected at the beginning (REST), mid-point (MID) and end of exercise (POST) for determination of EPCs (CD31(+)CD34(bright)CD45(dim)CD133(+)) and CECs (CD31(bright)CD34(+)CD45(-)CD133(-)) by flow cytometry. Between group differences in EPCs and CECs were examined using two-way ANOVA, followed by Tukey's HSD post hoc, where appropriate. Statistical significance set at p ≤ 0.05. RESULTS: Both EPCs and CECs were similar between groups at REST (p = 0.18-0.94). During MICE, EPCs remained unchanged in JIA (p = 0.95) but increased significantly at POST in controls (REST: 0.91 ± 0.55 × 10(6) cells/L vs. POST: 1.53 ± 0.36 × 10(6) cells/L, p = 0.04). Compared with controls, lower levels of EPCs were observed in JIA at MID (0.48 ± 0.50 × 10(6) cells/L vs. 1.10 ± 0.39 × 10(6) cells/L, p = 0.01) and POST (0.38 ± 0.34 × 10(6) cells/L vs. 1.53 ± 0.36 × 10(6) cells/L, p < 0.001) during MICE. No changes were detected in CECs with MICE in JIA and controls (p = 0.69). Neither EPCs nor CECs were modified with HIIE (p = 0.28-0.69). CONCLUSION: Youth with JIA demonstrated a blunted EPC response to MICE when compared with controls. Future work should examine factors that may increase or normalize EPC mobilization in JIA.

Effects of acute exercise on markers of inflammation in pediatric chronic kidney disease: a pilot study.

BACKGROUND: Children and adolescents with chronic kidney disease (CKD) are chronically exposed to high levels of inflammation, placing them at an increased risk of secondary health complications. Regular exercise may represent an effective therapy to reduce inflammation. The aims of this pilot study were to determine the effects of acute exercise on inflammation and immune cell counts in CKD. METHODS: Nine children and adolescents (4 males) with CKD stages III-V performed a graded exercise test to determine peak oxygen uptake (VO2peak). Following a 10-min break, participants cycled for 20 min at 50 % of VO2peak. Blood samples were collected before and after the exercise period for the determination of complete blood counts, natural killer cells (NK(bright), NK(dim)) and circulating progenitor cell (CPC) counts, as well as interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) concentrations. RESULTS: Complete blood counts and NK(dim) cell and CPC counts were unchanged with exercise. Following exercise, NK(bright) cell counts increased (7.4 ± 4.3 vs. 12.2 ± 8.3 × 10(6) cells/L; p = 0.02), while trends were observed for an increase in IL-6 (2.1 ± 2.2 vs. 2.7 ± 2.6 pg/mL; p = 0.08), decrease in TNF-α (4.5 ± 1.2 vs. 4.2 ± 1.0 pg/mL; p = 0.08) and an increase in the IL-6:TNF-α ratio (0.6 ± 0.7 vs. 0.8 ± 0.8; p = 0.07). CONCLUSIONS: Our findings suggest that acute exercise may create an anti-inflammatory environment in children and adolescents with CKD stages III-V.