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1.
Ecotoxicol Environ Saf ; 207: 111101, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32905937

RESUMO

To regulate the presence of contaminants in Brazilian water, the Brazilian Environmental Council (CONAMA) promulgates regulations regarding the concentrations of given compounds that are supposed to be safe for aquatic life. Considering these regulations, this study tested the effects of considered safe levels of lithium (2.5 mgL-1) and selenium (0.01 mgL-1), isolated and mixed, on the American bullfrog (Lithobates catesbeianus) tadpoles. The evaluation was done through the use of biomarkers of larval development as total wet weight (TWW), snout-vent-length (SVL), hind-limb-length (HLL), activity level (AL), histologic evaluation of the thyroid gland and the mortality rate. The tadpoles were allocated into four groups (n = 20 each): a control group (CT); a group exposed to lithium (LI), a group exposed to selenium (SE), and a group exposed to both lithium and selenium (SELI). The whole assay was carried out over 21 days, with two rounds of data collection (on 7th and 21st day) to evaluate the responses over time. A statistical reduction in the AL was observed in the tadpoles from the LI and SELI groups after 7 days of exposure, the same pattern was observed after 21 days. Histological analyses of the thyroid gland showed signs of up-regulation (i.e. statistic reduction in number and area of the follicles, as well a significant reduction in the area of the gland) in all exposed groups, which represents an endocrine response as an adaptative strategy to deal with polluted aquatic environment. The stress triggered by the polluted medium is discussed.


Assuntos
Lítio/toxicidade , Metamorfose Biológica/efeitos dos fármacos , Rana catesbeiana/fisiologia , Selênio/toxicidade , Poluentes Químicos da Água/toxicidade , Aceleração , Animais , Bioensaio , Brasil , Poluentes Ambientais , Larva/fisiologia , Metamorfose Biológica/fisiologia , Glândula Tireoide , Estados Unidos
2.
Bioresour Technol ; 319: 124131, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33002784

RESUMO

In this study, the multiple effects of granular activated carbon (GAC) on sludge anaerobic digestion at ambient (16-24 °C), mesophilic (35 °C) and thermophilic (55 °C) temperature were investigated. After GAC addition, although the methane yields of raw sludge were reduced by 6.5%-36.9%, the lag phases of methanogenesis were shortened by 19.3%-30.6% and the reductions of methane yields were declined to only 5.9%-8.1% simultaneously for pretreated sludge. The inhibitory substances like phenols that generated by thermal pretreatment were reduced after GAC addition, which were demonstrated to be responsible for the methanogenic acceleration. Meanwhile, the methane reduction due to the non-selective adsorption by GAC could be mitigated by pretreatment and elevated temperature. Thus, a strategy coupling thermal pretreatment with detoxification by GAC was proposed to improve the methane production rate and avoid the negative effects during sludge anaerobic digestion with GAC addition.


Assuntos
Metano , Esgotos , Aceleração , Anaerobiose , Reatores Biológicos , Carvão Vegetal
3.
Artigo em Inglês | MEDLINE | ID: mdl-33138002

RESUMO

The purpose of this study was to test the relationships between training workload (WL) parameters with variations in anaerobic power and change of direction (COD) in under-16 soccer players. Twenty-three elite players under 16 years were daily monitored for their WL across 20 weeks during the competition soccer season. Additionally, players were assessed three times for anthropometric, body composition, COD, and anaerobic power. A correlational analysis between the mean differences between assessments and accumulated WL parameters were conducted. Moreover, a regression analysis was executed to explain the variations in the percentage of change in fitness levels considering the accumulated WL parameters and peak height velocity. The accumulated daily loads during one week showed a large and a moderate correlation with peak power and COD at different periods of the season. Regression analysis showed no significant predictions for COD (F(12, 10) = 1.2, p = 0.41) prediction, acute load (F(12, 10) = 0.63, p = 0.78), or chronic load (F(12, 10) = 0.59, p = 0.81). In conclusion, it may be assumed that the values of the chronic workload and the accumulated training monotony can be used to better explain the physical capacities of young soccer players, suggesting the importance of psychophysiological instruments to identify the effects of the training process in this population.


Assuntos
Esforço Físico , Futebol , Carga de Trabalho , Aceleração , Adolescente , Composição Corporal , Teste de Esforço , Humanos , Irã (Geográfico)
4.
Orv Hetil ; 161(47): 2011-2013, 2020 11 22.
Artigo em Húngaro | MEDLINE | ID: mdl-33226358

RESUMO

Összefoglaló. A bal oldali septalis fasciculusblokk EKG-manifesztációja a magas, keskeny R-hullám a V1-2-elvezetésekben. Egy eset kapcsán ennek frekvenciafüggo megjelenése kerül bemutatásra. A hazai szakirodalomban még nem ismert a bal oldali septalis fasciculusblokk, irodalmilag is ritka ennek frekvenciafüggo megjelenése. Orv Hetil. 2020; 161(47): 2011-2013. Summary. Electrocardiogram with dominant R wave in the right precordial leads (V1-2) are the most important ECG manifestations of left septal fascicular block. A case is presented with acceleration-dependent left septal fascicular block. Its a rare manifestation of the tetrafascicular conduction system, not published in the Hungarian medical records. Orv Hetil. 2020; 161(47): 2011-2013.


Assuntos
Bloqueio de Ramo/diagnóstico , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Aceleração , Bloqueio de Ramo/etiologia , Doença do Sistema de Condução Cardíaco , Humanos
5.
PLoS One ; 15(10): e0240162, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33064732

RESUMO

It has been documented that up to 22% of all soccer injuries are concussions. This is in part due to players purposely using their head to direct the ball during play. To provide a more complete understanding of head trauma in soccer athletes, this study characterized the effects of four soccer ball characteristics (size, inflation pressure, mass, velocity) on the resulting peak impact force as it relates to the potential for incurring neurophysiological changes. A total of six hundred trials were performed on size 4 and 5 soccer balls as well as a novel lightweight soccer ball. Impact force was measured with a force plate and ball velocity was determined using motion capture. These data were used, in conjunction with dimensional analysis to relate impact force to ball size, mass, velocity, and pressure. Reasonable reductions in allowable ball parameters resulted in a 19.7% decrease in peak impact force. Adjustments to ball parameters could reduce a high cumulative peak translational acceleration soccer athlete down into a previously defined safer low loading range. In addition, it was noted that water absorption by soccer balls can result in masses that substantially increase impact force and quickly surpass the NCAA weight limit for game play. Additional research is required to determine whether varying soccer ball characteristics will enable soccer players to avoid persistent neurophysiological deficits or what additional interventions may be necessary and the legal implications of these data are discussed.


Assuntos
Aceleração/efeitos adversos , Traumatismos em Atletas/prevenção & controle , Concussão Encefálica/prevenção & controle , Futebol/lesões , Estresse Mecânico , Traumatismos em Atletas/etiologia , Fenômenos Biomecânicos , Concussão Encefálica/etiologia , Humanos , Modelos Biológicos
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2699-2702, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018563

RESUMO

We have developed an accelerometric system with a custom-designed patch probe and signal acquisition hardware to acquire the carotid wall displacement from the soft tissue surface for arterial stiffness evaluation. A subject-specific calibration model was developed to estimate the morphology of accurate carotid diameter waveform, using a standard ultrasound B-mode imaging system as the reference. Following the one-time calibration, the accelerometric system continuously acquired a non-invasive carotid lumen diameter waveform. The capability of the accelerometric system to measure the carotid stiffness index (ß) in-vivo was experimentally validated by performing measurements on 8 normotensive subjects in the supine position. The repeatability and reproducibility of the results were investigated and were found to be comparable to those provided by ultrasound imaging systems. Further, the variation of arterial stiffness index measurements on different days was studied to verify the ability of the system to give a stable measure of stiffness. The accuracy of the observed results was confirmed with the state-of-art B-mode ultrasound imaging system. The results were found to be stable over a day, indicating the utility of the system for a reliable measure of non-invasive carotid arterial stiffness.


Assuntos
Rigidez Vascular , Aceleração , Pletismografia , Reprodutibilidade dos Testes , Ultrassonografia
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3138-3141, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018670

RESUMO

The design of effective rehabilitation protocols relies on the ability to accurately assess the physical condition and the rehabilitative needs of the patient. Monitoring muscle fatigue can increase the usability of rehabilitative and restorative devices as it helps avoiding premature tiring and injury of patients whose resistance is already compromised. In this study, we collected EMG and accelerometer data from one healthy subject during a 30-minute walk on treadmill to determine the variations of muscle activation, and gait acceleration patterns, which, however subtle, could be interpreted as early indicators of muscle fatigue. Results show an increasing Tibialis Anterior (TA) and decreasing Soleus (SOL) and Gastrocnemius (GASL, GASM) activation towards the end of the task as compared to the beginning, as well as increasing acceleration peaks during the middle swing phase. By following the approach outlined here we can assess the efficiency and reduction of metabolic cost achieved by an exoskeleton. Furthermore, muscle fatigue may be linked to the efficacy of gait rehabilitation, where decreased muscle fatigue across sessions possibly indicates longer retention of benefits after training and increased walking capacity. This methodology can be used to benchmark novel exoskeletons, monitor fatigue to avoid premature tiring of patients, and optimize rehabilitation therapies.


Assuntos
Fadiga Muscular , Caminhada , Aceleração , Eletromiografia , Marcha , Humanos
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3940-3944, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018862

RESUMO

Energy expenditure (EE) estimation is an important factor in tracking personal activity and preventing chronic diseases, such as obesity and diabetes. The challenge is to provide accurate EE estimations in free-living environment through portable and unobtrusive devices. In this paper, we present an experimental study to estimate energy expenditure during sitting, standing and treadmill walking using a smartwatch. We introduce a novel methodology, which aims to improve the EE estimation by first separating sedentary (sitting and standing) and non-sedentary (walking) activities, followed by estimating the walking speeds and then calculating the energy expenditure using advanced machine learning based regression models. Ten young adults participated in the experimental trials. Our results showed that combining activity type and walking speed information with the acceleration counts substantially improved the accuracy of regression models for estimating EE. On average, the activity-based models provided 7% better EE estimation than the traditional acceleration-based models.


Assuntos
Metabolismo Energético , Velocidade de Caminhada , Aceleração , Humanos , Postura Sentada , Caminhada , Adulto Jovem
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4034-4037, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018884

RESUMO

Freezing of gait (FOG) is a major hindrance to daily mobility and can lead to falling in people with Parkinson's disease. While wearable accelerometers and gyroscopes have been commonly used for FOG detection, foot plantar pressure distribution could also be considered for this application, given its usefulness in previous gait-based classification. This research examined 325 plantar-pressure based features and 132 acceleration-based features extracted from the walking data of five males with Parkinson's disease who experienced FOG. A set of 61 features calculated from the time domain, Fast Fourier transform (FFT), and wavelet transform (WT) were extracted from multiple input signals; including, total ground reaction force, foot centre of pressure (COP) position, COP velocity, COP acceleration, and 3D ankle acceleration. Minimum-redundancy maximum relevance (mRMR) feature selection was used to rank all features. Plantar-pressure based features accounted for 4 of the top 5 features (ranks 2, 3, 4, 5); the remaining feature was an ankle acceleration based feature (rank 1). The three highest ranked features were the freeze index (calculated from ankle acceleration), total power in the frequency domain (calculated using the FFT from COP velocity), and mean of the WT detail coefficients (calculated from COP velocity). This preliminary analysis demonstrated that features calculated from plantar pressure, specifically COP velocity, performed comparably to ankle acceleration features. Thus, feature sets for FOG detection may benefit from plantar-pressure based features.


Assuntos
Transtornos Neurológicos da Marcha , Doença de Parkinson , Aceleração , Tornozelo , Marcha , Transtornos Neurológicos da Marcha/diagnóstico , Humanos , Masculino , Doença de Parkinson/diagnóstico
10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4571-4574, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019011

RESUMO

Cerebellar ataxia (CA) refers to the impaired balance and coordination resulting from injury or degeneration of the cerebellum. Testing balance is one of the simplest means of assessing CA. This study compares instrumented assessment and clinical assessment scales of the balance test called Romberg's test. Inertial Measurement Unit (IMU) data were collected from a sensor attached to their chest of 53 subjects while they performed the test. The corresponding clinical scores were also tabulated. Using this data, 99 features were extracted to quantify acceleration, tremor and displacement of body sway. These features were filtered to identify the subset that better characterize the distinctive behavior of CA subjects. Elastic Net Regression model resulted a greater agreement (0.70 Pearson coefficient) with the clinical SARA scores. The overall results indicated that data from a single IMU sensor is sufficient to accurately assess balance in CA. The significance of this study is that evaluation of balance using Recurrence Quantification Analysis produces a comprehensive framework for the assessment of CA.


Assuntos
Ataxia Cerebelar , Aceleração , Ataxia Cerebelar/diagnóstico , Humanos , Equilíbrio Postural , Tórax , Tremor
11.
Nat Commun ; 11(1): 5446, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116118

RESUMO

Continuous, battery-free operation of sensor nodes requires ultra-low-power sensing and data-logging techniques. Here we report that by directly coupling a sensor/transducer signal into globally asymptotically stable monotonic dynamical systems based on Fowler-Nordheim quantum tunneling, one can achieve self-powered sensing at an energy budget that is currently unachievable using conventional energy harvesting methods. The proposed device uses a differential architecture to compensate for environmental variations and the device can retain sensed information for durations ranging from hours to days. With a theoretical operating energy budget less than 10 attojoules, we demonstrate that when integrated with a miniature piezoelectric transducer the proposed sensor-data-logger can measure cumulative "action" due to ambient mechanical acceleration without any additional external power.


Assuntos
Engenharia Biomédica/instrumentação , Coleta de Dados/instrumentação , Fontes de Energia Elétrica , Transdutores , Aceleração , Fontes de Energia Bioelétrica , Engenharia Biomédica/estatística & dados numéricos , Coleta de Dados/estatística & dados numéricos , Eletrônica/instrumentação , Eletrônica/estatística & dados numéricos , Desenho de Equipamento , Fenômenos Mecânicos , Processamento de Sinais Assistido por Computador/instrumentação
12.
Dent Med Probl ; 57(3): 285-293, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32909702

RESUMO

BACKGROUND: Only a few studies in the literature have reported patient-centered outcomes associated with minimally invasive corticotomy, and thus, related scientific evidence is limited. OBJECTIVES: The objective of this study was to evaluate patient-centered outcomes associated with upper canine retraction assisted with piezocision or laser-assisted flapless corticotomy (LAFC). MATERIAL AND METHODS: Thirty-two patients (19 females, 13 males) at a mean age of 18.25 ±3.05 years were randomly divided into 2 equal groups: the LAFC group (LG; n = 16) and the piezocision group (PG; n = 16). In each group, the surgical procedure was randomly assigned to one side of the maxillary arch, and the other side served as the control. Standardized questionnaires using the numerical rating scale (NRS) were distributed to all patients during the 1st month after the surgical procedure at 4 time points: 24 h (T1); 3 days (T2); 7 days (T3); and 14 days (T4). The patients' responses were obtained, regarding their feelings of pain, discomfort, swelling, eating difficulty, jaw movement restriction, analgesic consumption, and satisfaction. RESULTS: The levels of pain, discomfort, swelling, and difficulty in chewing were significantly greater at the experimental sides as compared to the control sides only at T1 in both groups (p < 0.05). The levels of pain and discomfort in LG were significantly lower than those in PG only at T1 (p = 0.013 and p = 0.009, respectively) whereas there were no significant differences between the groups regarding swelling, eating difficulty, jaw movement restriction, and analgesic consumption. The patients in both groups reported high levels of satisfaction, with no significant differences. The levels of pain, discomfort, swelling, eating difficulty, and jaw movement restriction were dramatically decreased 1 day after flapless corticotomy treatment in both groups (p < 0.05). CONCLUSIONS: Both LAFC and piezocision were associated with high levels of pain, discomfort, swelling, and difficulty in chewing at T1. Laser-assisted flapless corticotomy caused less pain and discomfort than piezocision.


Assuntos
Maxila , Técnicas de Movimentação Dentária , Aceleração , Adolescente , Adulto , Feminino , Humanos , Masculino , Maxila/cirurgia , Dor , Assistência Centrada no Paciente , Adulto Jovem
13.
Sci Rep ; 10(1): 15744, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978447

RESUMO

In this experimental study we film the landings of Aedes aegypti mosquitoes to characterize landing behaviors and kinetics, limitations, and the passive physiological mechanics they employ to land on a vertical surface. A typical landing involves 1-2 bounces, reducing inbound momentum by more than half before the mosquito firmly attaches to a surface. Mosquitoes initially approach landing surfaces at 0.1-0.6 m/s, decelerating to zero velocity in approximately 5 ms at accelerations as high as 5.5 gravities. Unlike Dipteran relatives, mosquitoes do not visibly prepare for landing with leg adjustments or body pitching. Instead mosquitoes rely on damping by deforming two forelimbs and buckling of the proboscis, which also serves to distribute the impact force, lessening the potential of detection by a mammalian host. The rebound response of a landing mosquito is well-characterized by a passive mass-spring-damper model which permits the calculation of force across impact velocity. The landing force of the average mosquito in our study is approximately 40 [Formula: see text]N corresponding to an impact velocity of 0.24 m/s. The substrate contact velocity which produces a force perceptible to humans, 0.42 m/s, is above 85% of experimentally observed landing speeds.


Assuntos
Aedes/fisiologia , Aceleração , Animais , Feminino , Voo Animal , Cinética , Extremidade Inferior/fisiologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-32916804

RESUMO

The purpose of this study was two-fold: (1) to describe weekly average values for training monotony (TM) and training strain (TS) and their variations across the full soccer season, based on the number of accelerations and decelerations; (2) to analyze the differences between starter and non-starter players on weekly average TM and TS values for the pre-season and three in-season periods. In total, 21 professional soccer players were evaluated over 48 weeks during the full-season. The TM and TS were calculated based on the number of accelerations and decelerations at zone 1, zone 2 and zone 3, respectively. The results revealed that starters presented higher values compared to non-starters throughout the full season for all variables analyzed (all, p < 0.05). Generally, there were higher values in the pre-season. Specifically, accelerations at zones 1, 2 and 3 revealed moderate to very large significance of the starters compared to non-starters over the full-season. Decelerations at zone 1, 2 and 3 presented moderate to nearly optimally significant greater weekly averages for starters compared to non-starters during the full season. In conclusion, the TM and TS values were higher for starters compared to non-starters through the full-season, which confirms that the training session does not provide a sufficient load to non-starter soccer players during the full-season.


Assuntos
Acelerometria , Futebol , Aceleração , Humanos , Condicionamento Físico Humano , Estações do Ano , Futebol/fisiologia
15.
Sports Biomech ; 19(6): 723-737, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32942954

RESUMO

The aim of this study was to understand if and how surface-induced vibrations and road bike damping affect short-term neuromuscular performance in cycling. Thirty cyclists (mass 75.9 ± 8.9 kg, height 1.82 ± 0.05 m, Vo2max 63.0 ± 6.8 ml/min/kg) performed steady-state and maximum effort tests with and without vibration exposure (front dropout: 44 Hz, 4.1 mm; rear dropout: 38 Hz, 3.5 mm) on a damped and a nondamped bike. Transmitted accelerations to the musculoskeletal system, activation of lower extremity muscles (gast. med., soleus, vast. med., rec. fem.) and upper body muscles (erec. spinae, deltoideus, tric. brachii), oxygen uptake, heart rate and crank power output were measured. The main findings indicate a transmission of vibration to the whole body, but since no major propulsive muscles increase their activation with vibration, the systemic energy demand increases only marginally with vibration. Damping reduces vibrations at the upper body, which indicates an increase in comfort, but has no effect on the vibration transfer to the lower extremities. Therefore, road bike damping does not affect neuromuscular response of the propulsive muscle groups and energy demand. Consequently, short-term power output does not increase with damping.


Assuntos
Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Meio Ambiente , Músculo Esquelético/fisiologia , Vibração , Aceleração , Fenômenos Biomecânicos , Estudos Transversais , Frequência Cardíaca/fisiologia , Humanos , Extremidade Inferior/fisiologia , Masculino , Músculo Esquelético/inervação , Consumo de Oxigênio/fisiologia , Tronco/fisiologia , Extremidade Superior/fisiologia
16.
J Sports Sci Med ; 19(3): 613-619, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32874114

RESUMO

This study quantified the match-play activity profiles of international touch rugby and different positional physical outputs in comparison with training specificity. Between November 2019 and January 2020, 82 half-matches and 173 training global positioning system data from 16 national male touch rugby players (mean ± SD: age 23.71 ± 3.90 years, height 1.73 ± 0.05 m, weight 65.38 ± 9.08 kg, touch rugby training experience 6.09 ± 3.31 years) were recorded. The distance covered by wings in half-match (1676.66 ± 444.80 m) was more than that of link (1311.35 ± 223.59 m) and middle (1383.52 ± 246.55 m) by a large effect (partial η 2 = 0.19), which was mainly attributed to walking and jogging (< 4.00 m·s-1). Meanwhile, the middles covered more running distance (4.00-5.50 m·s-1) than other positions. No significant positional group difference was observed for distance covered >5.50 m·s-1, maximum velocity, and the ratio of acceleration and deceleration in matches. Training intensity was close to the match-play outputs only for the high-speed running distance at ≥ 5.50 m·s-1. However, the training activity pattern consistently showed a disparity with the match-play outputs, in terms of shorter normalized training distance covered, less recovery distance covered at ≤ 5.50 m·s-1, higher maximum velocity, and heavier weighting to acceleration in training activities. The current study highlights for the first time that in-match deceleration capacity and active recovery pacing strategy may be essential to touch rugby players. The data provided practitioners a deeper understanding of the physical demands of national touch rugby and allowed them to align the training with the match-play intensity.


Assuntos
Comportamento Competitivo/fisiologia , Futebol Americano/fisiologia , Sistemas de Informação Geográfica , Condicionamento Físico Humano/fisiologia , Corrida/fisiologia , Análise e Desempenho de Tarefas , Aceleração , Adulto , Desaceleração , Humanos , Corrida Moderada/fisiologia , Masculino , Estudos Prospectivos , Caminhada/fisiologia , Adulto Jovem
17.
PLoS One ; 15(9): e0233475, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946458

RESUMO

We aimed to compare the match-play and kinematic demands of the translation and rotation movements of elite wheelchair padel players as a function of match results. Twenty-two elite male players were video-analysed with a two-dimensional direct linear transformation (DLT) -corrected video system across seven matches of a professional tournament. Distance, turns, changes of direction, linear and angular speed, acceleration and the players' heart rate (HR) were recorded. Losing couples in wheelchair padel covered greater distances than winners (P <0.001; r = 0.024) and did so at a higher speed (P <0.001; r = 0.06), while making greater efforts by accelerating (P <0.001; ∅ = -0.021), braking (P <0.001; ∅ = -0.014), and remaining less time stationary (P <0.001; ∅ = 0.059). In addition, losers performed more turns per rally (P <0.001; r = 0.04) at a faster speed, greater angular accelerations (P <0.001; V = 0.06) and greater average (P = 0.007; d = 0.91) and maximum (P = 0.20; d = 0.69) HR values. These data suggest that winner couples performed a better court positioning and employed a strategy to move the opponent during rallies in order to avoid them optimally reaching the ball.


Assuntos
Desempenho Atlético/fisiologia , Paratletas , Esportes/fisiologia , Cadeiras de Rodas , Aceleração , Adulto , Fenômenos Biomecânicos/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos de Tempo e Movimento , Gravação em Vídeo
18.
PLoS One ; 15(9): e0238359, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986731

RESUMO

Based on the characteristics of expressway driving behavior, a punishment avoidance variable is introduced in this study to modify the theory of planned behavior (TPB), and the analysis model of expressway speeding behavior is improved and verified through survey data. The mechanism of the effects of attitude to behavior, subjective norm, perceived behavioral control, and punishment avoidance on expressway speeding behavior is analyzed. The results show that drivers lack a correct understanding of expressway speeding behavior and that punishment avoidance has a significant effect on expressway speeding behavior. Younger drivers (25-34), men, High income earners, and those who received more penalty points are considered prone to speeding. The study provides valuable contributions to the development of the Chinese version of the expressway speeding analysis model.


Assuntos
Aceleração , Condução de Veículo/psicologia , Condução de Veículo/estatística & dados numéricos , Teoria Psicológica , Punição , Adolescente , Adulto , Idoso , Atitude , China , Humanos , Intenção , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sociológicos , Inquéritos e Questionários , Adulto Jovem
19.
J Sports Sci ; 38(19): 2200-2207, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32921248

RESUMO

The aims of this study were (a) to describe the kinematics underlying the phenomenon of the knee of the swing leg passing medially in front of the athlete during the single push (SP) phase of the block sprint start, and (b) to determine the relationships between block phase pelvis range of motion (RoM), 1st step width and block phase performance. Three-dimensional kinematic data (250 Hz) were collected from eleven competitive sprinters (100 m PB: 11.17 ± 0.41) performing maximal effort block starts. The joint angles of the rear hip with respect to the pelvis and the pelvis segment angles with respect to the laboratory coordinate system were calculated during the block start phase to the end of the 1st stance. A combination of pelvis list and rotation (not hip adduction) was coupled with the thigh of the swing leg moving medially during the SP phase. A very high positive correlation was found between pelvic list RoM and 1st step width (r = 0.799, p = 0.003). No other significant correlations were found. Attempting to reduce pelvic RoM or changing frontal and transverse plane hip joint angles to minimise medial thigh motion is unlikely to lead to an improvement to performance.


Assuntos
Articulação do Joelho/fisiologia , Pelve/fisiologia , Corrida/fisiologia , Aceleração , Fenômenos Biomecânicos , Feminino , Análise da Marcha , Articulação do Quadril/fisiologia , Humanos , Masculino , Postura/fisiologia , Amplitude de Movimento Articular , Coxa da Perna/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
20.
J Sports Med Phys Fitness ; 60(8): 1072-1080, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32955833

RESUMO

BACKGROUND: This study aims at describing and comparing each other male and female soccer players kicking instep a stationary ball. The different measures we collected by the 3D motion capture system Movit G1 and the High-Speed Camera (240 fps) were considered as dependent variables, whereas the gender was considered as the independent one. METHODS: Twenty soccer well trained non-professional players: 10 men (age: 25.3±6.5 yrs; height 1.80±0.07 m; body mass 76.9±13.2 kg) and 10 women (age: 19±3.34 yrs; height 1.64±0.07 m; body mass 58.2±7.2 kg) volunteered to participate in the study. RESULTS: Gender differences were found, with a statistical significance (P<0.05) or interesting magnitude (Cohen d>0.5). The most relevant ones were the differences in hip extension of the kicking leg when the foot of the supporting one touches the ground, just before the impact on the ball (independent sample t-Test; P=0.03; Cohen d=1.64) and the speed of the ball, reached immediately after kicking (P<0.001;d=1.23). CONCLUSIONS: These results, together with the greater pelvic acceleration shown by men compared to women, highlight the need to develop a gender-differentiated training model, in order to customize the kicking technique in women and to reduce the likelihood, currently higher than for men, of kicking related injuries.


Assuntos
Extremidade Inferior/fisiologia , Futebol/fisiologia , Aceleração , Adulto , Fenômenos Biomecânicos , Feminino , Pé/fisiologia , Quadril/fisiologia , Humanos , Joelho/fisiologia , Masculino , Pelve/fisiologia , Caracteres Sexuais , Fatores Sexuais , Estudos de Tempo e Movimento , Adulto Jovem
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