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1.
Int J Sports Med ; 41(1): 21-26, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31756737

RESUMO

The aim of the study was to verify the relative contributions of energetic and kinematic parameters to the performance in 400-m front crawl test. Fourteen middle-distance swimmers participated in the study. Oxygen consumption was measured directly and blood samples were collected to assay lactate concentration. Both oxygen consumption and lactate concentration were used to calculate the: (i) overall energy expenditure, (ii) anaerobic (alactic and lactic) and (iii) aerobic contributions. The mean centre of mass speed and intracycle velocity variation were determined through three-dimensional kinematic analysis. Mean completion time was 315.64±26.91s. Energetic contributions were as follows: 6.1±0.28% from alactic anaerobic metabolism, 5.9±0.63% from anaerobic lactic and 87.8±0.88% from aerobic. Mean intracycle velocity variation was 0.14±0.03. The results indicated that performance of 400-m test relies predominantly on aerobic power. Parameters such as lactate, mean speed, anaerobic lactic and alactic (kW) correlated with performance of 400-m test (p <0.05). Multiple linear regressions indicated that mean centre of mass speed and anaerobic alactic (kW) determined the 400-m test performance (R2=0.92). Even though the T400 is characterized by aerobic metabolism, the anaerobic alactic component cannot be negligible at this competition level.


Assuntos
Metabolismo Energético/fisiologia , Teste de Esforço/métodos , Natação/fisiologia , Fenômenos Biomecânicos/fisiologia , Comportamento Competitivo/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Oxigênio/sangue , Consumo de Oxigênio , Estudos de Tempo e Movimento , Gravação em Vídeo , Adulto Jovem
2.
J Sports Sci ; 38(1): 106-113, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31658883

RESUMO

The purpose of this study was to develop an automated method for identifying and classifying change of direction (COD) movements in professional tennis using tracking data. Three sport science and strength and conditioning experts coded match-play footage of nineteen professional tennis players (9 male and 10 female) from the Australian Open Grand Slam for COD of medium and high intensity. A total of 1,494 changes were identified and aligned with 2D player position sampled at 25 Hz based on camera tracking data. Several machine learning classifiers were trained and tested on a set of 1,128 time-motion features. A random forest algorithm was found to have the best out-of-sample performance, classifying medium and high intensity changes with an F1-score of 0.729. This research offers a novel and applicable way for utilising player tracking data and machine learning techniques to automatically identify and classify COD movements in professional tennis.


Assuntos
Aprendizado de Máquina , Destreza Motora/classificação , Tênis/fisiologia , Adulto , Fenômenos Biomecânicos , Comportamento Competitivo/classificação , Comportamento Competitivo/fisiologia , Estudos Transversais , Feminino , Humanos , Masculino , Destreza Motora/fisiologia , Reprodutibilidade dos Testes , Estudos de Tempo e Movimento , Adulto Jovem
3.
J Sports Sci ; 38(1): 46-52, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31658889

RESUMO

The purpose of this study was to determine the influence of pelvis and torso angular jerk on a performance indicator of hitting, specifically hand velocity. Eighteen softball athletes were analysed (20.3 ± 1.6 years; 164.9 ± 24.9 cm; 74.4 ± 14.0 kg). Participants were instructed to execute 3 maximum effort swings off a stationary tee at the middle "strike-zone" location. Angular jerk data were analysed during the acceleration phase of the swing, the time between foot contact and ball contact. Quadratic regression analyses were conducted to examine the relationship of minimal pelvis angular jerk and minimal torso angular jerk to angular hand velocity at ball contact. No significant relationship was found between pelvis angular jerk and angular hand velocity at ball contact (r = 0.192, p = 0.754). The curvilinear regression model for pelvis angular jerk produced: R2 = 0.037; F (2, 17) = 0.288; p = 0.754. Lack of significant findings suggests a relationship between jerk and angular hand velocity does not exist within female softball hitting. Future research should investigate the timing of minimal jerk through the acceleration phase as a predictor of angular hand velocity, rather than the value of jerk itself.


Assuntos
Desempenho Atlético/fisiologia , Beisebol/fisiologia , Mãos/fisiologia , Pelve/fisiologia , Tronco/fisiologia , Aceleração , Fenômenos Biomecânicos , Feminino , Humanos , Destreza Motora/fisiologia , Movimento/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
4.
J Sports Sci ; 38(2): 206-213, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31722621

RESUMO

A novel 3D motion capture analysis assessed the efficacy of insoles in maintaining the foot position on the midsole platform inside the shoe during rapid change of direction manoeuvres used in team sports. An insole (TI) with increased static (35%) and dynamic (49%) coefficient of friction compared to a regular insole (SI) was tested. Change of direction performance was faster (p < .001) and perceived to be faster (p < .001) in TI compared to SI. Participants utilised greater coefficient of friction in TI compared to SI during a complete turn, but not during a 20 degree side-cut. In-shoe foot sliding reduced across the forefoot and midfoot during the braking phase of the turn and in the rearfoot during the side-cut in TI. Greater in-shoe foot sliding occurred in the turn than the side-cut across all foot regions. Results provide guidance for athletic footwear design to help limit in-shoe foot sliding and improve change of direction performance.


Assuntos
Desempenho Atlético/fisiologia , Desenho de Equipamento , Destreza Motora/fisiologia , Sapatos , Adulto , Desempenho Atlético/psicologia , Fenômenos Biomecânicos , Feminino , Fricção , Humanos , Masculino , Percepção , Estudos de Tempo e Movimento , Adulto Jovem
5.
J Sports Sci ; 38(1): 53-61, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31623521

RESUMO

This study aimed 1) to examine the validity of inertial measurement unit (IMU)-based hip flexion strength test, and 2) to investigate the hip flexion strength test as an indicator of sprint performance. Eight males performed five repeated hip flexion-extension, while leg motion was recorded using an IMU and a motion capture system (Mocap). As the second experiment, 24 male athletes performed the IMU-based hip flexion strength test and sprinted 50 m, during which step-to-step ground reaction force (GRF) was recorded. The strength test variables were calculated using IMU and Mocap data including angular impulse, mean moment, and positive and negative work and power. Using GRF data, step-to-step spatiotemporal variables were obtained. The results showed high intra-class correlation coefficient and correlation coefficient (both >0.909) between IMU and Mocap for angular impulse, mean moment, positive work and power. The hip flexion mean moment showed significant correlation with running speed from the 5th-8th step section onwards. The angular impulse, mean moment, positive work and power are recommended to be used for the IMU-based hip flexion strength test variables in terms of accuracy and validity. Moreover, the proposed IMU-based hip flexion strength test can be an indicator for better sprinting performance.


Assuntos
Desempenho Atlético/fisiologia , Teste de Esforço/métodos , Quadril/fisiologia , Força Muscular/fisiologia , Corrida/fisiologia , Aceleração , Adulto , Fenômenos Biomecânicos , Humanos , Masculino , Reprodutibilidade dos Testes , Estudos de Tempo e Movimento , Adulto Jovem
6.
Int J Sports Med ; 40(13): 863-870, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31593991

RESUMO

Previous cross-sectional studies have reported that higher drop heights do not always result in improved performance, and may increase injury risk during drop jumps (DJ). The purpose of this study was to analyze the kinematics and kinetics during the DJ in order to determine the relative drop height that maximize performance without exposing the lower extremity joints to unnecessary loads. Twenty male Division I college volleyball players volunteered. Data were collected using 11 infrared cameras and two force platforms. Participants performed three maximal effort countermovement jumps (CMJ). Subsequently, 50, 75, 100, 125, and 150% CMJ height (CMJH) was used to scale their relative drop height for three DJ trials per height. There was a significant increase in the landing phase impulse when the drop height exceeded 100%CMJH (p<0.05). At 125% and 150%CMJH, the negative work of knee and ankle significantly increased. The incoming velocity, kinetic energy, landing depth, maximum ground reaction force, landing impulse and power absorption of knee and ankle all increased with drop height (p<0.05). DJ height and reactive strength index following the drop landing were not statistically different between any of the drop heights (p>0.05). 50% to 100%CMJH may be the appropriate individual relative drop height for the DJ.


Assuntos
Extremidade Inferior/fisiologia , Exercício Pliométrico , Voleibol/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Estudos Transversais , Articulação do Quadril/fisiologia , Humanos , Cinética , Articulação do Joelho/fisiologia , Masculino , Estudos de Tempo e Movimento , Adulto Jovem
7.
Sports Biomech ; 18(6): 663-685, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31543063

RESUMO

The golfer's body (trunk/arms/club) can be modeled as an inclined axle-chain system and the rotations of its parts observed on the functional swing plane (FSP) can represent the actual angular motions closely. The purpose of this study was to investigate the effects of pelvis-shoulders torsional separation style on the kinematic sequences employed by the axle-chain system in golf driving. Seventy-four male skilled golfers (handicap ≤ 3) were assigned to five groups based on their shoulder girdle motion and X-factor stretch characteristics: Late Shoulder Acceleration, Large Downswing Stretch, Large Backswing Stretch, Medium Total Stretch, and Small Total Stretch. Swing trials were captured by an optical system and the hip-line, thorax, shoulder-line, upper-lever, club, and wrist angular positions/velocities were calculated on the FSP. Kinematic sequences were established based on the timings of the peak angular velocities (backswing and downswing sequences) and the backswing-to-downswing transition time points (transition sequence). The backswing and transition sequences were somewhat consistent across the groups, showing full or partial proximal-to-distal sequences with minor variations. The downswing sequence was inconsistent across the groups and the angular velocity peaks of the body segments were not significantly separated. Various swing characteristics associated with the separation styles influenced the motion sequences.


Assuntos
Golfe/fisiologia , Destreza Motora/fisiologia , Pelve/fisiologia , Ombro/fisiologia , Adulto , Braço/fisiologia , Fenômenos Biomecânicos , Humanos , Masculino , Movimento , Tórax/fisiologia , Estudos de Tempo e Movimento
8.
Gait Posture ; 74: 114-120, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31499405

RESUMO

PURPOSE: The aim of the study was to evaluate the effect of sensorimotor training on balance measures, and proprioception, among middle-aged and older adults with diabetic peripheral neuropathy (DPN). METHODS: A randomized controlled study with four parallel arms (two intervention groups and two control groups) was conducted at CPRS, Jamia Millia Islamia. Thirty-seven individuals were selected on the basis of inclusion and exclusion criteria. Of these, 16 middle-aged and 21 older adults were randomly allocated to intervention and control groups, respectively. Subjects in the intervention group were administered eight weeks (3days/week) of sensorimotor training, involving 10 different types of exercises, progressed from easy to hard every two weeks, along with diabetes and foot care education; subjects in control group received diabetes and foot care education only. Outcomes measures involved static and dynamic balance measures, centre of pressure (COP) range, COP sway, and proprioception, measured before and after eight weeks. RESULTS: Baseline measures showed significant age effect for timed up and go test (TUG) (p =  0.002), one leg stance (OLS) in eyes open (EO) and eyes closed (EC) (p ≤ 0.041), COP range in front (p =  0.007), back (p =  0.009) and right direction (p =  0.013), COP sway with visual feedback in front-back direction (p =  0.027), COP sway without visual feedback in left-right direction (p =  0.028), and proprioception in right direction (p =  0.026). After intervention, OLS EO and EC on both legs showed significant time effect (p ≤  0.003), group effect as well as time×group interaction (p <  0.05), and age effect and time×age interaction (p ≤  0.04). Functional reach test, TUG, COP range, COP sway, and proprioception were found with significant time effect (p <  0.03), group effect, and time×group interaction (p ≤  0.035). Age effect and time×age interaction were found to be non-significant for all COP ranges and COP sway. CONCLUSION: Sensorimotor training improved static and dynamic balance as well as proprioception measures after eight weeks of exercise intervention. Static balance showed greater improvement in the middle-aged than older aged adults, while dynamic balance and proprioception showed similar results for both.


Assuntos
Neuropatias Diabéticas/fisiopatologia , Terapia por Exercício/métodos , Transtornos Neurológicos da Marcha/fisiopatologia , Modalidades de Fisioterapia , Equilíbrio Postural/fisiologia , Propriocepção/fisiologia , Idoso , Análise de Variância , Retroalimentação Sensorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos de Tempo e Movimento
9.
J Med Life ; 12(2): 194-198, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31481979

RESUMO

Most studies on patients with normal pressure hydrocephalus (NPH) regard pre-post Tap test and long-term follow-up after shunt surgery. Quantitative and qualitative assessment tools specific to rehabilitation medicine can provide an objective measurement of the benefit of the neurosurgical intervention at 1-month follow-up. The aim of this retrospective study was to assess the early benefit of the ventriculoperitoneal shunt with low or medium pressure valve on the gait capacity of persons with NPH, one month after surgery. This is a retrospective study reviewing 19 inpatients with NPH who underwent neurosurgery for ventriculoperitoneal shunt with low or medium pressure valve, one month after a positive result on a tap test, in a 5-year period. The assessments regarding the gait abilities were performed 24 hours before the surgical intervention and one month after surgery. Assessment tools used were: the 3 meters Timed Up and Go Test (TUG), the 10 Meters Walking Test (10MWT) and the Berg Balance Scale. A positive response to the tap test predicted improvements of gait and balance in patients with NPH after shunt surgery. Best results in regards to gait and balance are achieved when early diagnosis and intervention are performed. Complex comorbidities generate and enhance significant and persistent gait impairment.


Assuntos
Marcha/fisiologia , Derivação Ventriculoperitoneal , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equilíbrio Postural/fisiologia , Estudos Retrospectivos , Estudos de Tempo e Movimento , Resultado do Tratamento , Caminhada
10.
Int J Sports Med ; 40(12): 756-761, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31476782

RESUMO

We studied the effects of supramaximal interval exercise (SIE) with or without antihypertensive medication (AHM) on 21-hr blood pressure (BP) response. Twelve hypertensive patients chronically medicated with AHM, underwent three trials in a randomized order: a) control trial without exercise and substituting their AHM with a placebo (PLAC); b) placebo medicine and a morning bout of SIE (PLAC+SIE), and c) combining AHM and exercise (AHM+SIE). Acute and ambulatory blood pressure responses were measured for 21-hr after treatment. 20 min after treatment, systolic blood pressure (SBP) readings were reduced, similar to readings after PLAC+SIE (-9.7±6.0 mmHg, P<0.001) and AHM+SIE (-10.4±7.9 mmHg, P=0.001). 21 h after treatment, SBP remained reduced after PLAC+SIE (125±12 mmHg, P=0.022) and AHM+SIE (122±12 mmHg, P=0.013) compared to PLAC (132±16 mmHg). The BP reduction in PLAC+SIE faded out at 4 a.m., while in AHM+SIE it continued overnight. At night, BP reduction was larger in AHM+SIE than PLAC+SIE (-5.6±4.0 mmHg, P=0.006). Our data shows that a bout of supramaximal aerobic interval exercise in combination with ARB medication in the morning elicits a sustained blood pressure reduction lasting at least 21-h. Thus, the combination of exercise and angiotensin receptor blocker medication seems superior to exercise alone for acutely decreasing blood pressure.


Assuntos
Anti-Hipertensivos/uso terapêutico , Treinamento Intervalado de Alta Intensidade , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Hipotensão Pós-Exercício/fisiopatologia , Actigrafia/métodos , Idoso , Pressão Sanguínea/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Feminino , Monitores de Aptidão Física , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Postura/fisiologia , Estudos de Tempo e Movimento
11.
Hum Mov Sci ; 67: 102513, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31493621

RESUMO

BACKGROUND: Anxiety disorders are the most common mental disorders. Changes in psychomotor behavior can be observed in gross motor skills, with gait disturbances thought to reflect defective brain functions in psychiatric conditions. While balance deficits are well documented in anxiety, only little is known about gait characteristics of people with anxiety. OBJECTIVE: This study wishes to examine the existence of differences in gait, balance, mobility and muscle strength between people with anxiety and healthy individuals, and to investigate the relationship between level of anxiety and motor characteristics. METHODS: An observational study was conducted in a psychiatric out-patient unit at a large Israeli general hospital. The sample consisted of 93 participants, ages 18-65: 48 of them (27 female, 21 male) categorized as having anxiety, and 45 (25 female, 20 male) without anxiety. Participants were divided into two groups of various ages and both genders, and completed two questionnaires and four physical tests: objective anxiety assessment (Hamilton Anxiety Rating Scale); spatiotemporal gait parameters (10-meter walking test); balance function (Unipedal Stance Test); muscle strength evaluation, and mobility (Time Up and Go Test). No attempt was made to correlate between the anxiety and control groups based on age and/or gender. RESULTS: Participants with anxiety (both genders) were characterized by slower walking speed, shorter step length, and fewer steps per minute (p < 0.001), as well as balance deficiency and mobility dysfunction (p < 0.001), compared to the control group. Muscle strength in women with anxiety was found to be significantly lower than in healthy women. CONCLUSIONS: To the best of our knowledge, this study is the first of its kind to examine spatiotemporal gait components in patients with anxiety. Based on the findings, there is room to consider implementing gait analysis into the physical examination of patients with anxiety, as well as muscle strength, balance, and mobility function. Correct assessment and proper treatment of these aspects might contribute to the well-being of patients with anxiety.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Marcha/fisiologia , Força Muscular/fisiologia , Equilíbrio Postural/fisiologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/fisiopatologia , Amplitude de Movimento Articular , Inquéritos e Questionários , Estudos de Tempo e Movimento , Caminhada/fisiologia , Adulto Jovem
12.
J Sports Sci ; 37(23): 2685-2690, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31418312

RESUMO

The aim of this study was to assess the reliability and validity of the bar-mounted PUSH BandTM 2.0 to determine peak and mean velocity during the bench press exercise with a moderate (60% one repetition maximum [1RM]) and heavy (90% 1RM) load. We did this by simultaneously recording peak and mean velocity using the PUSH BandTM 2.0 and three-dimensional motion capture from participants bench pressing with 60% and 90% 1RM. We used ordinary least products regression to assess within-session reliability and whether the PUSH BandTM 2.0 could accurately predict motion capture velocity. Results showed that PUSH BandTM 2.0 and motion capture peak and mean velocity reliability was acceptable with both loads. While there was a tendency for the PUSH BandTM 2.0 to slightly overestimate peak and mean velocity, there was no fixed bias. However, mean velocity with 60 and 90% 1RM demonstrated proportional bias (differences between predicted and motion capture values increase with magnitude). Therefore, PUSH BandTM 2.0 peak velocity with 60 and 90% 1RM is valid, but mean velocity is not.


Assuntos
Treinamento de Resistência/instrumentação , Treinamento de Resistência/métodos , Levantamento de Peso/fisiologia , Adulto , Teste de Esforço/métodos , Humanos , Masculino , Força Muscular/fisiologia , Análise de Regressão , Reprodutibilidade dos Testes , Estudos de Tempo e Movimento , Adulto Jovem
13.
Int J Med Inform ; 129: 253-259, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31445264

RESUMO

BACKGROUND: Qualitative studies have provided important insights into how hospital pharmacists' work changes when electronic medication management (EMM) systems are introduced. Quantitative studies of work practice change are rare. Despite the use of EMM systems internationally, there are no cross-country comparative studies of their impact on health professionals' work. We aimed to quantify and compare the type and magnitude of changes in hospital pharmacists' work pre- and post-EMM implementation in two countries. METHODS: Parallel, direct observational, time and motion studies of pharmacists in Australia and England pre- and post-EMM implementation. 20 pharmacists were observed: 9 in an Australian 440-bed hospital (155 h); and 11 pharmacists in a 500-bed English hospital (258 h). The Work Observation Method By Activity Timing (WOMBAT) software was used to collect observational data. Proportions of observed time in 11 tasks by study period (pre- versus post-EMM) and site, time spent with others or alone, and using different tools (e.g computers, paper) were calculated. Magnitude of changes between pre- and post-EMM by task and country were determined using z-tests for proportions adjusting for multiple testing. RESULTS: At baseline, Australian and English pharmacists spent the greatest proportion of time in medication review. Post-EMM, time in medication review (Australia 21.6%-27.5%; England 27.1%-33.8%) and history-taking (Australia 7.6%-13.3%; England 19.5%-28.9%) significantly increased. Despite country differences in these tasks at baseline, the magnitude of changes did not significantly differ. English pharmacists increased time engaged in medication discussions with patients post-EMM (from 5.9% to 10.8%; p = 0.01). The Australian rate did not change (18.0%-27.2%; p = 0.09), but was higher at baseline. Post-EMM, Australian pharmacists spent 63.4% of time working alone, compared to 92.0% for English pharmacists. CONCLUSIONS: EMM systems impacted the same core areas of work and had a similar magnitude of effect on pharmacists' work in both countries. Anticipated reductions in medication review and history taking were not observed.


Assuntos
Registros Eletrônicos de Saúde , Austrália , Inglaterra , Pessoal de Saúde , Hospitais , Humanos , Sistemas de Medicação , Farmacêuticos/organização & administração , Estudos de Tempo e Movimento
14.
BMC Health Serv Res ; 19(1): 533, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366394

RESUMO

BACKGROUND: In some low-resource settings bubble continuous positive airway pressure (bCPAP) is increasingly used to treat children with pneumonia. However, the time required for healthcare workers (HCWs) to administer bCPAP is unknown and may have implementation implications. This study aims to compare HCW time spent administering bCPAP and low-flow nasal oxygen care at a district hospital in Malawi during CPAP IMPACT (Improving Mortality for Pneumonia in African Children Trial). METHODS: Eligible participants were 1-59 months old with WHO-defined severe pneumonia and HIV-infection, HIV-exposure, severe malnutrition, or hypoxemia and were randomized to either bCPAP or oxygen. We used time motion techniques to observe hospital care in four hour blocks during treatment initiation or follow up (maintenance). HCW mean time per patient at the bedside over the observation period was calculated by study arm. RESULTS: Overall, bCPAP required an average of 34.71 min per patient more than low-flow nasal oxygen to initiate (bCPAP, 118.18 min (standard deviation (SD) 42.73 min); oxygen, 83.47 min (SD, 20.18 min), p < 0.01). During initiation, HCWs spent, on average, 12.45 min longer per patient setting up bCPAP equipment (p < 0.01) and 11.13 min longer per patient setting up the bCPAP nasal interface (p < 0.01), compared to oxygen equipment and nasal cannula set-up. During maintenance care, HCWs spent longer on average per patient adjusting bCPAP, compared to oxygen equipment (bCPAP 4.57 min (SD, 4.78 min); oxygen, 1.52 min (SD, 2.50 min), p = 0.03). CONCLUSION: Effective bCPAP implementation in low-resource settings will likely create additional HCW burden relative to usual pneumonia care with oxygen. TRIAL REGISTRATION: Clinicaltrials.gov NCT02484183 , June 29, 2015.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas/métodos , Corpo Clínico Hospitalar , Oxigenoterapia/métodos , Pneumonia/terapia , Carga de Trabalho/estatística & dados numéricos , Pré-Escolar , Feminino , Pesquisa sobre Serviços de Saúde , Hospitais de Distrito , Humanos , Lactente , Malaui/epidemiologia , Masculino , Pneumonia/mortalidade , Fatores de Tempo , Estudos de Tempo e Movimento
15.
Int J Sports Med ; 40(11): 725-731, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31382298

RESUMO

The aims of this study were twofold: 1) to examine lower extremity coordination during bodyweight squats performed at two different tempos, and 2) to establish a reliable measure of segment coordination variability. Eighteen subjects (10 F, 8 M) completed bodyweight squats at preferred (self-paced) and non-preferred (metronome-paced) tempos. A modified vector coding approach used kinematic data to compute absolute couplings patterns and coordination variability for three couplings (foot-shank, shank-thigh, thigh-trunk) in three planes of motion for the descent and ascent phases of a squat cycle. A coordination variability reliability equation was used to determine the number of squats needed for a reliable index of movement variability relative to total variability over 20 squats. Tempo did not significantly alter the absolute coordination patterns of any couplings. The reliability equation revealed that 5-9 squats were needed for a reliable coordination variability measure. Nine squats provided a reliable measure of coordination that is comparable to using 20 double leg squats in the calculation. Using nine squats ensures reliable calculations in the frontal, sagittal and transverse planes at preferred and non-preferred speeds. These results can be used to guide clinical evaluation of acceptable levels of movement variability during rehabilitation.


Assuntos
Exercício/fisiologia , Extremidade Inferior/fisiologia , Destreza Motora/fisiologia , Fenômenos Biomecânicos , Humanos , Masculino , Estudos de Tempo e Movimento
16.
J Sports Sci ; 37(22): 2578-2587, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31352873

RESUMO

This study examined the validity of a tool that assesses tackle and ruck technique in training and established reference data for tackle, ball-carry and ruck technique at different levels of play in rugby union. One hundred and thirty-one amateur rugby union players; 37 senior, 51 first-grade academy and 43 second-grade academy players, participated in a two-on-two contact drill. The drill was filmed and the players' tackle, ball-carry and ruck technique were assessed using standardized technical criteria. Senior level players scored significantly higher in all three assessments; tackle technique senior vs academy 1st (p < 0.01, effect size (ES) = 0.7, moderate), senior vs academy 2nd (p < 0.01, ES = 0.7, moderate); ball-carry technique senior vs academy 1st (p < 0.01, ES = 0.6, moderate), senior vs academy 2nd (p < 0.01, ES = 0.8, moderate); ruck technique senior vs academy 1st (p < 0.01, ES = 0.7, moderate), senior vs academy 2nd (p < 0.01, ES = 0.4, small). These findings emphasize the importance of developing contact technique to allow players to progress to higher levels, and provide validity to an assessment tool which can facilitate this process.


Assuntos
Desempenho Atlético/fisiologia , Teste de Esforço/métodos , Futebol Americano/fisiologia , Destreza Motora/fisiologia , Estudos Transversais , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes , Estudos de Tempo e Movimento , Gravação em Vídeo
17.
Rev Assoc Med Bras (1992) ; 65(6): 810-817, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31340309

RESUMO

BACKGROUND: Time-motion analysis has been used to provide detailed insight into surfers' performance. This study evaluated surfers' activity times at the Portuguese surfing championship in order to account for the time spent in each surfing activity. METHODS: Eighty-seven individually recorded videos of surfers were analyzed, showing their activity over the entire heat, and video analysis software was used to obtain each surfer's activity profile in the competition. RESULTS: The results breakdown by time percentage show that the surfers were paddling 50.9% of the time, sprint paddling for wave 1.9%, were stationary 34.1% of the time, wave riding 3.7%, and involved in miscellaneous activities (e.g., duck diving, board recovery, etc.) 9.4% of the total time. Average times spent in each surfing activity were 18.6 seconds for paddling, 2.9 seconds for sprint paddling for a wave, 21.7 seconds for the stationary period, 11.5 seconds for wave riding, and 6.9 seconds for miscellaneous activities. CONCLUSIONS: The data revealed that the most performed heat activity was paddling, allowing us to conclude that surfing is basically a long-arm paddling activity and that this activity constitutes a specific surfing competition demand, which in turn means that individual surfer's data can be used as a starting point for the development of tailored conditioning training programs.


Assuntos
Desempenho Atlético/fisiologia , Movimento/fisiologia , Estudos de Tempo e Movimento , Esportes Aquáticos/fisiologia , Atletas , Estudos Transversais , Feminino , Humanos , Masculino , Portugal , Valores de Referência , Fatores Sexuais , Fatores de Tempo , Gravação em Vídeo
18.
J Sports Sci ; 37(22): 2530-2537, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31345111

RESUMO

The aims of this study were (a) to compare players' physical demands between different playing positions in elite U18 basketball games and (b) to identify different clusters of performance. Data were collected from 94 male subjects (age: 17.4 ± 0.7 years), competing in a Euroleague Basketball Tournament. Guards covered a greater relative distance than centres and forwards (small to moderate effect). Forwards and guards had more peak accelerations, high accelerations and high decelerations than centres (moderate to large effects). A cluster analysis allowed to classify all cases into three different groups (Lower, Medium and Higher activity demands), containing 37.4%, 52.8% and 9.8% of the cases, respectively. The high accelerations, high decelerations, peak accelerations and total distance covered were the variables that most contributed to classify the players into the new groups. The percentage of cases distributed in the clusters according to playing position, game type (worst vs worst, mixed opposition, best vs best) and team were different. Centres have lower physical demands specially related with the number of accelerations and decelerations at high intensity and the peak acceleration when compared with guards. Each team has a different activity profile, that does not seem to influence the tournament outcome.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Comportamento Competitivo/fisiologia , Esforço Físico/fisiologia , Aceleração , Adolescente , Humanos , Masculino , Destreza Motora/fisiologia , Estudos de Tempo e Movimento
19.
J Sports Sci ; 37(21): 2475-2482, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31311452

RESUMO

Previous research suggests that landing mechanics may be affected by the mechanics of the preceding jump take-off. The purpose of the present study was to investigate whether jump take-off mechanics influence the subsequent landing mechanics. Female volleyball (n = 17) and ice hockey (n = 19) players performed maximal vertical jumps with forefoot and heel take-off strategies. During forefoot and heel jumps, participants were instructed to shift their weight to their forefoot or heel, respectively, and push through this portion of the foot throughout the jump. Jump mechanics were examined using 3D motion analysis, where lower extremity net joint moment (NJM) work, NJM, and segment angles were compared between forefoot and heel jumps using multivariate ANOVA. During jump take-off, participants performed more positive ankle plantar flexor and knee extensor NJM work in forefoot compared to heel jumps (P < 0.05). From initial foot contact to foot flat, participants performed more negative ankle plantar flexor and hip extensor NJM work during heel compared to forefoot jumps (P < 0.05). The present results demonstrate that using a heel take-off strategy results in a different distribution of lower extremity NJM work and NJM during landing compared to landings following forefoot jumps.


Assuntos
Pé/fisiologia , Calcanhar/fisiologia , Extremidade Inferior/fisiologia , Exercício Pliométrico , Adolescente , Tornozelo/fisiologia , Fenômenos Biomecânicos , Feminino , Hóquei/fisiologia , Humanos , Joelho/fisiologia , Estudos de Tempo e Movimento , Voleibol/fisiologia , Adulto Jovem
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