Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 68
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Genet Med ; 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33564151

RESUMO

PURPOSE: To understand the consequences of the 3q29 deletion on medical, neurodevelopmental, psychiatric, brain structural, and neurological sequalae by systematic evaluation of affected individuals. To develop evidence-based recommendations using these data for effective clinical care. METHODS: Thirty-two individuals with the 3q29 deletion were evaluated using a defined phenotyping protocol and standardized data collection instruments. RESULTS: Medical manifestations were varied and reported across nearly every organ system. The most severe manifestations were congenital heart defects (25%) and the most common were gastrointestinal symptoms (81%). Physical examination revealed a high proportion of musculoskeletal findings (81%). Neurodevelopmental phenotypes represent a significant burden and include intellectual disability (34%), autism spectrum disorder (38%), executive function deficits (46%), and graphomotor weakness (78%). Psychiatric illness manifests across the lifespan with psychosis prodrome (15%), psychosis (20%), anxiety disorders (40%), and attention deficit-hyperactivity disorder (ADHD) (63%). Neuroimaging revealed structural anomalies of the posterior fossa, but on neurological exam study subjects displayed only mild or moderate motor vulnerabilities. CONCLUSION: By direct evaluation of 3q29 deletion study subjects, we document common features of the syndrome, including a high burden of neurodevelopmental and neuropsychiatric phenotypes. Evidence-based recommendations for evaluation, referral, and management are provided to help guide clinicians in the care of 3q29 deletion patients.

2.
IEEE Trans Med Imaging ; 40(5): 1363-1376, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33507867

RESUMO

To better understand early brain development in health and disorder, it is critical to accurately segment infant brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF). Deep learning-based methods have achieved state-of-the-art performance; h owever, one of the major limitations is that the learning-based methods may suffer from the multi-site issue, that is, the models trained on a dataset from one site may not be applicable to the datasets acquired from other sites with different imaging protocols/scanners. To promote methodological development in the community, the iSeg-2019 challenge (http://iseg2019.web.unc.edu) provides a set of 6-month infant subjects from multiple sites with different protocols/scanners for the participating methods. T raining/validation subjects are from UNC (MAP) and testing subjects are from UNC/UMN (BCP), Stanford University, and Emory University. By the time of writing, there are 30 automatic segmentation methods participated in the iSeg-2019. In this article, 8 top-ranked methods were reviewed by detailing their pipelines/implementations, presenting experimental results, and evaluating performance across different sites in terms of whole brain, regions of interest, and gyral landmark curves. We further pointed out their limitations and possible directions for addressing the multi-site issue. We find that multi-site consistency is still an open issue. We hope that the multi-site dataset in the iSeg-2019 and this review article will attract more researchers to address the challenging and critical multi-site issue in practice.

3.
Foot (Edinb) ; 45: 101745, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33032156

RESUMO

Preventing lateral ankle sprain injuries (LAS) in females competing in court sports is a high priority, as an athlete's risk for re-injury and developing long term dysfunction increases significantly after sustaining an acute LAS. Stability to the ankle joint is passively provided by the joint congruity and ligaments, and actively by the muscles acting on the foot. The ankle joint is most stable when loaded and dorsiflexed. However, during unanticipated changes of direction, typical in court sports, the foot is often in a vulnerable unloaded, plantarflexed position. Stability of the forefoot and controlling rearfoot movement to avoid excessive ankle inversion and adduction thus becomes imperative. Information regarding the coupling relationship between the forefoot (hallux and metatarsal segments) and the rearfoot (calcaneus segment) during unanticipated changes of direction is lacking. The aim of this study was to supplement current LAS prophylactic knowledge by describing and quantifying hallux-calcaneus and metatarsal-calcaneus coupling. The coupling angles between sagittal plane hallux, tri-planar metatarsal and frontal- and transverse plane calcaneus movement, respectively, were calculated with a modified vector coding technique which used segmental velocities in a local, anatomical reference frame instead of segmental angles in a global reference frame. Coupling relationships revealed anti-phase movement between sagittal- metatarsal and frontal plane calcaneus movement throughout stance. During loading, sagittal- and frontal plane metatarsal acceleration/deceleration were coupled with frontal-transverse plane calcaneus acceleration/deceleration respectively. The remainder of the braking phase was characterized by calcaneus eversion deceleration. During propulsion, the hallux and metatarsal segments increased plantar flexion velocity in response to calcaneus inversion and adduction acceleration. As the forefoot was the only point of contact during stance, the coupling between segments were most likely neuromuscular. Strengthening intrinsic and extrinsic foot muscles may thus contribute to foot and ankle stability, adding to current prophylactic LAS strategies.

4.
Pediatr Exerc Sci ; : 1-6, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32882683

RESUMO

PURPOSE: To investigate whether youth and adults can perceive differences in exertion between walking and running at speeds near the preferred transition speed (PTS) and if there are age-related differences in these perceptions. METHODS: A total of 49 youth (10-12 y, n = 21; 13-14 y, n = 10; 15-17 y, n = 18) and 13 adults (19-29 y) completed a walk-to-run transition protocol to determine PTS and peak oxygen uptake. The participants walked and ran on a treadmill at 5 speeds (PTS-0.28 m·s-1, PTS-0.14 m·s-1, PTS, PTS+0.14 m·s-1, PTS+0.28 m·s-1) and rated perceived exertion using the OMNI Perceived Exertion (OMNI-RPE) scale. Oxygen consumption was measured during the walk-to-run transition protocol to obtain the relative intensity (percentage of peak oxygen uptake) at PTS. OMNI-RPE scores at all speeds and percentage of peak oxygen uptake at PTS were compared between age groups. RESULTS: The 10- to 12-year-olds transitioned at a higher percentage of peak oxygen uptake than adults (64.54 [10.18] vs 52.22 [11.40], respectively; P = .035). The 10- to 14-year-olds generally reported higher OMNI-RPE scores than the 15- to 17-year-olds and adults (P < .050). In addition, the 10- to 14-year-olds failed to distinguish differences in OMNI-RPE between walking and running at PTS and PTS+0.14 m·s-1. CONCLUSIONS: Children aged 10-14 years are less able to distinguish whether walking or running requires less effort at speeds near the PTS compared with adults. The inability to judge which gait mode is less demanding could hinder the ability to minimize locomotive demands.

5.
Dev Psychopathol ; 32(4): 1175-1189, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32938507

RESUMO

The national priority to advance early detection and intervention for children with autism spectrum disorder (ASD) has not reduced the late age of ASD diagnosis in the US over several consecutive Centers for Disease Control and Prevention (CDC) surveillance cohorts, with traditionally under-served populations accessing diagnosis later still. In this review, we explore a potential perceptual barrier to this enterprise which views ASD in terms that are contradicted by current science, and which may have its origins in the current definition of the condition and in its historical associations. To address this perceptual barrier, we propose a re-definition of ASD in early brain development terms, with a view to revisit the world of opportunities afforded by current science to optimize children's outcomes despite the risks that they are born with. This view is presented here to counter outdated notions that potentially devastating disability is determined the moment a child is born, and that these burdens are inevitable, with opportunities for improvement being constrained to only alleviation of symptoms or limited improvements in adaptive skills. The impetus for this piece is the concern that such views of complex neurodevelopmental conditions, such as ASD, can become self-fulfilling science and policy, in ways that are diametrically opposed to what we currently know, and are learning every day, of how genetic risk becomes, or not, instantiated as lifetime disabilities.

6.
Obes Rev ; 21(12): e13121, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32779327

RESUMO

The adverse physical impacts of childhood obesity are increasingly being recognized. The objective of this study is to examine relationships between physical function and adiposity in youth. An umbrella review searched seven databases from inception to May 2019 for systematic reviews examining associations between adiposity and physical function in 0-20-year-olds. Findings were synthesized using the International Classification of Functioning, Disability and Health Framework and NHMRC FORM. Seventeen of 21 systematic reviews reported impairments to body function, including cardiorespiratory fitness (CRF), muscle function, balance/coordination, gait biomechanics, pain and injury. Six reviews reported activity restrictions in motor skills, running speed/agility and functional mobility, and two found inverse associations between adiposity and physical health-related quality of life (p-HRQOL). Some causal relationships indicated that adiposity inversely predicted p-HRQOL/CRF and CRF/muscle function inversely predicted adiposity. Assessments of physical function were heterogeneous and impacts on participation in life situations meaningful to the individual were largely unknown. Substantial evidence associates childhood overweight/obesity with reduced physical function. Associations were mainly cross-sectional, with causative evidence for some outcomes. Comprehensive physical function assessments by qualified health professionals are needed, along with targeted interventions to address deficits. Research should further examine causality of relationships, underlying mechanisms and participation challenges in real-life contexts.

7.
Res Q Exerc Sport ; : 1-8, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32633706

RESUMO

Background and objectives: The active and passive structures of the foot act in unison to not only be compliant enough to assist in ground reaction force attenuation but also resist deformation to provide a stable base of support. A foot that is unable to adjust to the imposed demands during high-intensity sporting activities may alter the moments and forces acting on the joints, increasing the risk of non-contact anterior cruciate ligament ruptures (ACLR) and lateral ankle sprains (LAS). Prophylactic strengthening programs are often used to reduce the risk of these injuries, but at present, very few prophylactic programs include foot-specific strengthening strategies. The aim of this theoretical review is to ascertain the prophylactic role strengthening muscles acting on the foot may have on ACLR and LAS injury risk. Methods: Literature relating to risk factors associated with ACLR and LAS injury and the anatomy and biomechanics of normal foot function was searched. In addition, ACLR and LAS injury prevention programs were also sought. A theoretical, narrative approach was followed to synthesize the information gathered from the articles. Results: The foot segments are governed by the congruity of the articulations and the activity of the foot muscles. As such, there is a coupling effect between shank, calcaneus, midfoot, and hallux movement which play a role in both ACLR and LAS injury risk. Conclusions: Strengthening the muscles acting on the foot may have a significant impact on ACLR and LAS injury risk.

8.
Sci Rep ; 10(1): 8267, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427957

RESUMO

Eye-blinking has emerged as a promising means of measuring viewer engagement with visual content. This method capitalizes on the fact that although we remain largely unaware of our eye-blinking in everyday situations, eye-blinks are inhibited at precise moments in time so as to minimize the loss of visual information that occurs during a blink. Probabilistically, the more important the visual information is to the viewer, the more likely he or she will be to inhibit blinking. In the present study, viewer engagement was experimentally manipulated in order to: (1) replicate past studies suggesting that a group of viewers will blink less often when watching content that they perceive as more important or relevant; (2) test the reliability of the measure by investigating constraints on the timescale over which blink rate patterns can be used to accurately quantify viewer engagement; and (3) examine whether blink rate patterns can be used to quantify what an individual - as opposed to a group of viewers-perceives as engaging. Results demonstrate that blink rate patterns can be used to measure changes in individual and group engagement that unfold over relatively short (1 second) and long (60 second) timescales. However, for individuals with lower blink rates, blink rate patterns may provide less optimal measures when engagement shifts rapidly (at intervals of 1 second or less). Findings support the use of eye-blink measures in future studies investigating a person's subjective perception of how engaging a stimulus is.

9.
Artigo em Inglês | MEDLINE | ID: mdl-32290586

RESUMO

Sedentary behavior increases risk for non-communicable diseases; associations may differ within different contexts (e.g., leisure time, occupational). This study examined associations between different types of sedentary behavior and disease risk factors in women, using objectively measured accelerometer-derived sedentary data. A validation study (n = 20 women) classified sedentary behavior into four categories: lying down; sitting (non-active); sitting (active); standing. A cross-sectional study (n = 348 women) examined associations between these classifications and disease risk factors (body composition, metabolic, inflammatory, blood lipid variables). Participants spent an average of 7 h 42 min per day in sedentary behavior; 58% of that time was classified as non-active sitting and 26% as active sitting. Non-active sitting showed significant (p ≤ 0.001) positive correlations with BMI (r = 0.244), body fat percent (r = 0.216), body mass (r = 0.236), fat mass (r = 0.241), leptin (r = 0.237), and negative correlations with HDL-cholesterol (r = -0.117, p = 0.031). Conversely, active sitting was significantly (p ≤ 0.001) negatively correlated with BMI (r = -0.300), body fat percent (r = -0.249), body mass (r = -0.305), fat mass (r = -0.320), leptin (r = -0.259), and positively correlated with HDL-cholesterol (r = 0.115, p = 0.035). In summary, sedentary behavior can be stratified using objectively measured accelerometer-derived activity data. Subsequently, different types of sedentary behaviors may differentially influence disease risk factors. Public health initiatives should account for sedentary classifications when developing sedentary behavior recommendations.


Assuntos
Atividades de Lazer , Comportamento Sedentário , Acelerometria , Índice de Massa Corporal , HDL-Colesterol , Estudos Transversais , Feminino , Humanos , Fatores de Risco
10.
BMC Musculoskelet Disord ; 20(1): 610, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861990

RESUMO

BACKGROUND: The aim of this systematic review was to identify principles of exercise interventions associated with improved physical function, weight management or musculoskeletal pain relief among young and middle-aged adults with obesity and propose an evidence-based exercise prescription that could assist in secondary prevention of osteoarthritis. METHODS: A structured electronic review was conducted using MEDLINE, PubMed, and SPORTDiscus. The search string included 1) "obes*" AND "exercise" AND "interven*" AND "musculoskeletal pain OR knee pain OR hip pain". Studies 1) were randomized controlled trials of humans, with a non-exercise control, 2) included participants aged 18-50 years, and 3) had outcomes that included physical function, musculoskeletal pain, and/or body composition. Studies were excluded if participants had peri-menopausal status, cancer, or obesity-related co-morbidities. A recommended exercise prescription was developed based on common principles used in the included exercise interventions with greatest change in function or pain. RESULTS: Seven studies were included. Similarities in exercise intensity (40-80% VO2max), frequency (three times per week), duration (30-60 min), and exercise mode (treadmill, cross-trainer, stationary bike, aquatic exercise) were observed in exercise interventions that resulted in improved physical function and/or pain, compared to non-exercise control groups. CONCLUSION: Common principles in exercise prescription for improvements in weight management, physical function and pain relief among otherwise healthy people with obesity. Exercise prescription including moderate intensity exercise for 30-60 min, three times per week can be considered an effective treatment for weight management and obesity-related musculoskeletal symptoms. Exercise should be recommended to at-risk individuals as part of secondary prevention of osteoarthritis.


Assuntos
Exercício Físico , Obesidade/terapia , Osteoartrite/prevenção & controle , Programas de Redução de Peso , Humanos , Obesidade/complicações , Osteoartrite/etiologia , Ensaios Clínicos Controlados Aleatórios como Assunto
11.
J Biomech Eng ; 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518430

RESUMO

Student engagement is an essential aspect of educational environments, and this is especially true for Science, Technology, Engineering, and Mathematics (STEM) disciplines, where student engagement declines in middle and high school years. Techniques for bolstering student engagement, such as hands-on learning, may be especially effective in the field of biomechanics since this discipline is rooted in STEM and has fundamental applications to everyday movement. To this end, this paper describes 1) the perceptions of student teachers in their first year of tertiary (undergraduate) education regarding the biomechanics content from their secondary (high school) education, and 2) a professional development initiative, in the form of a discipline specific teacher training workshop, to enhance biomechanics resources for teachers via peer networking. The perception of student teachers in their first year of tertiary education in teaching indicated a positive relationship between perception of secondary school teaching quality and self-confidence with specific biomechanical concepts. Open responses focused on the need to cover concepts thoroughly, using practical activities where possible, and taking time to ensure understanding before progressing to more advanced concepts. The teacher training workshop provided secondary school Physical Education teachers with an opportunity to network nationally with other teachers across New Zealand, and internationally with university-based biomechanics researchers. Peer focus groups helped to design and refine sets of experiential learning activities that could be easily implemented in the classroom.

12.
Hum Mov Sci ; 66: 600-606, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31277034

RESUMO

Adolescents tend to exhibit more variability in their gait patterns than adults, suggesting a lack of gait maturity during this period of ongoing musculoskeletal growth and development. However, there is a lack of consensus over the age at which mature gait patterns are achieved and the factors contributing to gait maturation. Therefore, the purpose of this study was to investigate gait control and maturity in adolescents by determining if differences existed between adolescents and adults in a) the amount of spatiotemporal variability of walking and running patterns across a range of speeds, and b) how swiftly gait patterns are adapted to increasing gait speed during the walk-to-run transition. Forty-six adolescents (10-12-year-olds, n = 17; 13-14-year-olds, n = 12; and 15-17-year-olds, n = 17) and 12 young adults completed an incrementally ramped treadmill test (+0.2 km·h-1 every 30 s) to determine the preferred transition speed (PTS) during a walk-to-run transition. Age-related differences in the variability of stride lengths and stride durations were assessed across 4 speeds (self-selected walking speed, PTS - 0.06 m·s-1, PTS + 0.06 m·s-1, PTS + 0.83 m·s-1). Repeated measures ANOVAs (p < 0.05) compared coefficients of variation for these spatiotemporal parameters, while a one-way ANOVA compared the numbers of gait transitions and speed increments used to identify PTS between the adolescent groups and young adults. Compared to adults, 10-12yo exhibited more spatiotemporal variability during all gait conditions, while 13-17yo only exhibited more variability at PTS + 0.06 m·s-1. No age-dependent pattern was observed in PTS values, but 10-12yo completed more gait transitions over more speed increments than 15-17yo and adults. The development of mature gait patterns is thus a progressive process, with walking maturing at an earlier age than running. As 10-12yo were unable to swiftly adapt gait patterns to the changing task demands, their control mechanisms of gait may not have fully matured yet.

13.
Aust N Z J Public Health ; 43(5): 443-450, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31091346

RESUMO

OBJECTIVES: Recreational physical activities of New Zealand women were examined to develop ethnic-specific suggestions encouraging physical activity (PA) participation as a targeted approach to reduce obesity rates among different groups. METHODS: Healthy Maori, Pacific and European women (n=331; 16-45 years of age) completed an online Recent Physical Activity Questionnaire to assess recreational PA and adherence to PA guidelines. Existing PA preferences were tailored to make ethnic-specific suggestions aimed at increasing PA participation. RESULTS: Achievement of PA guidelines was: Maori 74%; Pacific 60%; European 70%. Highest participation across all women was for walking (Maori 72%, Pacific 60%, European 83%), followed by floor exercise (Maori 54%, Pacific 37%, European 56%). Gym-type activities (e.g. weights, aerobics) and jogging were also common across ethnic groups. Group/team activities (dance, netball, touch football) were among the top 10 activities for Maori and Pacific, but not European women. CONCLUSION: Obesity rates among specific ethnic groups of New Zealand women might be reduced by promoting activities that are: family/whanau-oriented (netball, touch), community-linked (hula, dance) and outdoor-based. Implications for public health: Tailoring existing PA preferences to develop ethnic-specific sets of activity suggestions could be important avenues to increase PA participation, improving the PA habits and subsequent health of New Zealand women and their communities.


Assuntos
Grupos Étnicos/estatística & dados numéricos , Exercício Físico , Estilo de Vida/etnologia , Adolescente , Adulto , Comparação Transcultural , Estudos Transversais , Características Culturais , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Feminino , Humanos , Pessoa de Meia-Idade , Nova Zelândia , Grupo com Ancestrais Oceânicos/estatística & dados numéricos , Adulto Jovem
14.
J Biomech ; 88: 1-3, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-30967252

RESUMO

National Biomechanics Day (NBD) was initiated in 2016 as a nation-wide effort to introduce Biomechanics to high school students throughout the United States. After that initial year, many people around the world joined NBD to promote Biomechanics in their own countries. National Biomechanics Day became international. We describe NBD procedures and events in four of these countries with the intent of demonstrating mechanisms that may enable Biomechanists around the world to successfully join the NBD celebration.


Assuntos
Internacionalidade , Fenômenos Mecânicos , Estudantes , Adolescente , Fenômenos Biomecânicos , Humanos
16.
Pediatr Exerc Sci ; 31(3): 314-321, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30596335

RESUMO

PURPOSE: This study examined lower extremity kinematics in healthy weight (HW) and overweight (OW) children during water- and land-based stationary exercises (stationary running, frontal kick, and butt kick) at light submaximal intensity. METHODS: Participants included OW (N = 10; body fat percentage: 34.97 [8.60]) and HW (N = 15; body fat percentage: 18.33 [4.87]) children, aged 10 to 13 years. Spatiotemporal data, lower extremity joint kinematics, and rating of perceived exertion (RPE) were collected during water- and land-based stationary exercises. Repeated measures analysis of variance compared kinematic variables and RPE between groups and environments. A polygon area function compared coordination patterns between environments. RESULTS: RPE responses were significantly greater in OW than HW children on land (13.6 [0.7] vs 11.6 [0.7]; P < .001), whereas the RPE responses were similar between groups in water (11.2 [0.7] vs 11.1 [0.8]; P > .05). OW children were significantly more upright than HW children during land-based exercise, whereas there were no differences observed between groups during aquatic-based exercise. The duration of stance and swing phases, angular velocity, and cadence were significantly lower in water than on land. CONCLUSION: Compared with HW children, OW children performed stationary exercises in a more upright posture on land, with higher RPE. However, these differences diminished in water. Aquatic-based exercise may be effective in minimizing the effects of excess mass on OW children's ability to complete physical activity.


Assuntos
Exercício Físico , Extremidade Inferior/fisiologia , Sobrepeso , Adolescente , Fenômenos Biomecânicos , Criança , Feminino , Humanos , Masculino , Esforço Físico , Amplitude de Movimento Articular , Água
17.
Sports Biomech ; 18(6): 636-648, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29768096

RESUMO

A rugby scrum's front row must act uniformly to transfer maximal horizontal force and improve performance. This study investigated the muscle activation patterns of lower extremity muscles in front row forwards during live and machine scrums at professional and amateur levels. Electromyography was collected bilaterally on vastus lateralis, rectus femoris and gastrocnemius muscles of 75 male rugby prop players during live and machine scrums. ANOVAs compared muscle reaction time, rate of change in muscle amplitude and muscle amplitude between groups and conditions. Cross-correlation analysis explored muscle synchronicity. There were significantly greater rates of change in each muscle amplitude in professional players than amateur players. Additionally, there was significantly quicker muscle reaction time in all muscles, and greater amplitude in vastus lateralis and gastrocnemius, during the live scrum vs. machine condition. The professional props produced more synchronised muscle activation than amateur players and all players produced more synchronised muscle activation against the scrum machine vs. live scrummage. The results indicate a higher skill proficiency and muscle synchronicity in professional players. While scrum machine training is ideally suited for functional muscle strengthening during practice, to truly simulate the requirements of the scrum, training should incorporate the live situation as much as possible.


Assuntos
Futebol Americano/fisiologia , Extremidade Inferior/fisiologia , Músculo Esquelético/fisiologia , Adulto , Fenômenos Biomecânicos , Eletromiografia , Humanos , Masculino , Destreza Motora/fisiologia , Força Muscular/fisiologia , Condicionamento Físico Humano/instrumentação , Tempo de Reação , Adulto Jovem
18.
Motor Control ; 23(2): 262-271, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30518293

RESUMO

Multifractal analyses have been used in recent years as a way of studying balance, with the goal of understanding the patterns of movement of the center of pressure at different spatial scales. A multifractal detrended fluctuation analysis was used to compare obese and nonobese children to investigate the cause of previously demonstrated deficiencies in balance for obese children. Twenty-two children (11 obese and 11 nonobese), aged 8-15 years, performed 30-s trials of bilateral static balance on a plantar pressure distribution measuring device. Both the obese and nonobese groups demonstrated greater persistence for small fluctuations, but the effect was greater in the obese group. This was particularly evident with the eyes closed, where significant differences between the obese and nonobese were observed for small fluctuations. These results demonstrate that balance deficiencies in obese children may be the result of decreased proprioceptive abilities in obese children.


Assuntos
Obesidade/fisiopatologia , Equilíbrio Postural/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Dinâmica não Linear
19.
Pediatr Exerc Sci ; 31(1): 52-59, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30304978

RESUMO

PURPOSE: This study examined differences in lower extremity kinematics and muscle activation patterns between normal weight (NW) and overweight (OW) children during stationary exercises (running in place, frontal kick, and butt kick) at submaximal intensity. METHODS: Healthy children (aged 10-13 y) were stratified into OW (n = 10; body fat percentage: 34.97 [8.60]) and NW (n = 15; body fat percentage: 18.33 [4.87]). Electromyography was recorded for rectus femoris, vastus lateralis, biceps femoris, gastrocnemius, and tibialis anterior. In addition, the ratings of perceived exertion and range of motion of hip, knee, and ankle joints were collected during stationary exercises. Repeated-measures analysis of variance compared muscle activation, range of motion, and ratings of perceived exertion between groups and exercises. Friedman test examined sequencing of muscles recruitment. RESULTS: Compared with NW, OW experienced significantly greater ratings of perceived exertion (13.7 [0.8] vs 11.7 [0.7]; P < .001) and electromyography amplitude in all muscles apart from vastus lateralis during stationary exercises. In addition, NW children used more consistent muscles' recruitment pattern in comparison with OW children. The range of motion was similar between groups at all joints. CONCLUSION: OW children may adopt a more active neuromuscular strategy to provide greater stability and propulsion during stationary exercises. Stationary exercise can be prescribed to strengthen lower extremity muscles in OW children, but mode and intensity must be considered.


Assuntos
Exercício Físico/fisiologia , Extremidade Inferior/fisiopatologia , Músculo Esquelético/fisiopatologia , Obesidade Pediátrica/fisiopatologia , Adolescente , Fenômenos Biomecânicos/fisiologia , Criança , Eletromiografia/métodos , Feminino , Humanos , Masculino , Esforço Físico/fisiologia , Amplitude de Movimento Articular/fisiologia
20.
Brain Connect ; 8(9): 537-548, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30280929

RESUMO

Although a large body of research has identified discrete neuroanatomical regions involved in social cognition and behavior (the "social brain"), the existing findings are based largely on studies of specific brain structures defined within the context of particular tasks or for specific types of social behavior. The objective of the current work was to view these regions as nodes of a larger collective network and to quantitatively characterize both the topology of that network and the relative criticality of its many nodes. Large-scale data mining was performed to generate seed regions of the social brain. High-quality diffusion MRI data of typical adults were used to map anatomical networks of the social brain. Network topology and nodal centrality were analyzed using graph theory. The structural social brain network demonstrates a high degree of global functional integration with strong local segregation. Bilateral dorsomedial prefrontal cortices and amygdala play the most central roles in the network. Strong probabilistic evidence supports modular divisions of the social brain into subnetworks bearing good resemblance to functionally classified clusters. The present network-driven approach quantifies the structural topology of the social brain as a whole. This work can serve as a critical benchmark against which to compare (1) developmental change in social brain topology over time (from infancy through adolescence and beyond) and (2) atypical network topologies that may be a sign or symptom of disorder (as in conditions such as autism, Williams syndrome, schizophrenia, and others).


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Psicologia Social/métodos , Adulto , Tonsila do Cerebelo/fisiologia , Big Data , Conectoma , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Relações Interpessoais , Imagem por Ressonância Magnética/métodos , Masculino , Rede Nervosa/fisiologia , Vias Neurais/fisiologia , Córtex Pré-Frontal/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...