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Antonio W.S. Maciel, Leandro M. Pinto, Roberta C.A. Campos, Andressa C. Ferreira, Carlos A.A. Dias-Filho, Carlos J.M. Dias, Flávio de Oliveira Pires, Christiano B. Urtado, Bruno Rodrigues and Cristiano Teixeira Mostarda

Aim: To compare the acute effects of two resistance exercise sessions with different partial blood flow restrictions (BFR) on hemodynamic parameters and cardiac autonomic modulation in older women with metabolic syndrome. Methods: Thirty-nine older women (64.4 ± 4.5 years) were allocated into three groups: BFR0 = resistance exercise (20%, 1 maximum repetition [MR]) + 0% BFR; BFR60 = 20% 1 MR resistance exercise + 60% BFR; and BFR80 = 20% 1MR resistance exercise + 80% BFR. Results: A reduction of 14 mmHg (BFR60 group) and 13 mmHg (BRF80 group) was observed 48 hr after the first exercise session, while vagal modulation was increased in the BRF60 group after 24 and 48 hr. Conclusion: A low-intensity resistance exercise session with 60% and 80% of BFR resulted in blood pressure (systolic, diastolic, and mean) reduction and positive changes on heart rate variability after 24 h of a RE session.

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Dorthe Dalstrup Jakobsen, Jasper Schipperijn and Jens Meldgaard Bruun

Background: In Denmark, most children are not sufficiently physically active and only a few interventions have been found to increase long-term physical activity among overweight and obese children. The aim of our study was to investigate if children are physically active in correspondence to Danish recommendations after attending a multicomponent-overnight camp. Methods: A questionnaire was developed to estimate children’s physical activity level and behavior and investigate how transport, economy, availability, time, motivation, and knowledge about physical activity affect children’s physical activity level and behavior. Results: In this study, 60.9% of the children did vigorous physical activity (VPA) minimum 30 minutes 3 times per week up to 3 years after camp. Most children were physically active at a sports club (44.3%) and only 5.7% of the children did not participate in physical activity. Parental physical activity and child motivation toward physical activity were significantly (P < .05) associated with children doing VPA. Conclusion: Our findings suggest that 60.9% of children who attended camp engage in VPA after camp, which compared with a recent Danish study, is more frequent than children who did not attend camp. Further investigations are needed to determine the long-term health effects in children attending interventions such as multicomponent-overnight camps.

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Kim Gammage, Alyson Crozier, Alison Ede, Christopher Hill, Sean Locke, Eric Martin, Desi McEwan, Kathleen Mellano, Eva Pila, Matthew Stork and Svenja Wolf

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Marcelo Gonçalves Duarte, Glauber Carvalho Nobre, Thábata Viviane Brandão Gomes and Rodolfo Novelino Benda

Background: Studies related to the motor performance of children have suggested an interaction between organisms and the environment. Although motor development seems to be similar among people, the behavior is specific to the context that people are part of. Thus, the aim of this study was to compare the fundamental motor skill performance between indigenous (IN) and nonindigenous children. Methods: One hundred and thirteen children (43 IN and 70 nonindigenous children) between 8 and 10 years of age underwent the Test of Gross Motor Development—2. Results: A multivariate analysis showed a significant group main effect on both locomotor (p < .01) and object control (p < .01) performance with large and medium effect sizes (ηp2 values = .57–.40, respectively). The IN showed the highest scores for galloping, hopping, leaping, jumping, sliding, striking a stationary ball, stationary dribbling, catching a ball, kicking, and overhand throwing (p < .01) with small to large effect sizes (ηp2 values = .05–.50). Conclusion: The IN presented the highest levels of performance in fundamental motor skills compared with those of nonindigenous children. Most likely, IN have more opportunities for motor development in the environmental context (i.e., villages) where they live.

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Arthur Alves Dos Santos, James Sorce, Alexandra Schonning and Grant Bevill

This study evaluated the performance of 6 commercially available hard hat designs—differentiated by shell design, number of suspension points, and suspension tightening system—in regard to their ability to attenuate accelerations during vertical impacts to the head. Tests were conducted with impactor materials of steel, wood, and lead shot (resembling commonly seen materials in a construction site), weighing 1.8 and 3.6 kg and dropped from 1.83 m onto a Hybrid III head/neck assembly. All hard hats appreciably reduced head acceleration to the unprotected condition. However, neither the addition of extra suspension points nor variations in suspension tightening mechanism appreciably influenced performance. Therefore, these results indicate that additional features available in current hard hat designs do not improve protective capacity as related to head acceleration metrics.

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Daniella M. DiGuglielmo, Mireille E. Kelley, Mark A. Espeland, Zachary A. Gregory, Tanner D. Payne, Derek A. Jones, Tanner M. Filben, Alexander K. Powers, Joel D. Stitzel and Jillian E. Urban

To reduce head impact exposure (HIE) in youth football, further understanding of the context in which head impacts occur and the associated biomechanics is needed. The objective of this study was to evaluate the effect of contact characteristics on HIE during player versus player contact scenarios in youth football. Head impact data and time-synchronized video were collected from 4 youth football games over 2 seasons in which opposing teams were instrumented with the Head Impact Telemetry (HIT) System. Coded contact characteristics included the player’s role in the contact, player speed and body position, contact height, type, and direction, and head contact surface. Head accelerations were compared among the contact characteristics using mixed-effects models. Among 72 instrumented athletes, 446 contact scenarios (n = 557 impacts) with visible opposing instrumented players were identified. When at least one player had a recorded impact, players who were struck tended to have higher rotational acceleration than players in striking positions. When both players had a recorded impact, lighter players and taller players experienced higher mean head accelerations compared with heavier players and shorter players. Understanding the factors influencing HIE during contact events in football may help inform methods to reduce head injury risk.

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Meena Makhija, Jasobanta Sethi, Chitra Kataria, Harpreet Singh, Paula M. Ludewig and Vandana Phadke

Two-dimensional fluoroscopic imaging allows measurement of small magnitude humeral head translations that are prone to errors due to optical distortion, out-of-plane imaging, repeated manual identification of landmarks, and magnification. This article presents results from in vivo and in vitro fluoroscopy-based experiments that measure the errors and variability in estimating the humeral head translated position in true scapular plane and axillary views. The errors were expressed as bias and accuracy. The variability with repeated digitization was calculated using the intraclass correlation coefficient (ICC) and the standard error of measurement. Optical distortion caused underestimation of linear distances. The accuracy was 0.11 and 0.43 mm for in vitro and in vivo experiments, respectively, for optical distortion. The intrarater reliability was excellent for both views (ICC = .94 and .93), and interrater reliability was excellent (ICC = .95) for true scapular view but moderate (ICC = .74) for axillary views. The standard error of measurement ranged from 0.27 to 0.58 mm. The accuracy for the humeral head position in 10° out of true scapular plane images ranged from 0.80 to 0.87 mm. The current study quantifies the magnitude of error. The results suggest that suitable measures could be incorporated to minimize errors and variability for the measurement of glenohumeral parameters.