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1.
Exp Physiol ; 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014995

RESUMO

Accurate measurements of glycaemic control and the underpinning regulatory mechanisms are vital in human physiology research. Glycaemic control is the maintenance of blood glucose concentrations within optimal levels and is governed by physiological variables including insulin sensitivity, glucose tolerance and ß-cell function. These can be measured with a plethora of methods, all with their own benefits and limitations. Deciding on the best method to use is challenging and depends on the specific research question(s). This review therefore discusses the theory and procedure, validity and reliability and any special considerations of a range common methods used to measure glycaemic control, insulin sensitivity, glucose tolerance and ß-cell function. Methods reviewed include glycosylated haemoglobin, continuous glucose monitors, the oral glucose tolerance test, mixed meal tolerance test, hyperinsulinaemic euglycaemic clamp, hyperglycaemic clamp, intravenous glucose tolerance test and indices derived from both fasting concentrations and the oral glucose tolerance test. This review aims to help direct understanding, assessment and decisions regarding which method to use based on specific physiology-related research questions.

2.
J Strength Cond Res ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39016263

RESUMO

ABSTRACT: Houlton, LJ, Moody, JA, Bampouras, TM, and Esformes, JI. Acute effects of intracomplex rest after back squats on vertical jump performance during complex training. J Strength Cond Res XX(X): 000-000, 2024-Postactivation performance enhancement and complex-contrast sets are prevalent in sports science research. Typical complex-contrast sets consist of heavy back squats, an intracontrast rest period (ICRP) and vertical jumps (countermovement jumps [CMJs], or squat jumps [SJs]). Propulsive impulse (Jprop) is considered the leading indicator of jump performance. However, studies evaluating jump performance during complex-contrast sets use jump height as the primary performance measure, limiting insight into ICRP's effect on jump performance. We assessed the effect of a 3 repetition maximum (3RM) back squat and 6 ICRPs on vertical jump Jprop and associated force-time components. Fourteen subjects completed 12 experimental conditions, assigned equally to 4 testing sessions. Independent variables, in a 6 × 2 randomized, counterbalanced design, were ICRP (0, 60, 120, 180, 240, 300 seconds; ICRP0, ICRP60, ICRP120, ICRP180, ICRP240, ICRP300, respectively) and vertical jump (CMJ and SJ). Conditions consisted of baseline vertical jumps, followed by 3 back squat repetitions at 100% 3RM, an ICRP and experimental jumps. Symmetrized percentage changes between experimental and baseline jumps were assessed using repeated measures analysis of variance (ANOVA) and pairwise effect sizes. Results showed significant effects (p ≤ 0.05) on CMJ average rate of force development (RFD) between ICRP0 and ICRP120 and ICRP0 and ICRP300. Pairwise comparisons showed medium and large effect sizes for and increases in CMJ RFD (g = 0.83-2.69) whereas SJ RFD decreased (g = 0.81-2.57). Small effect sizes were found for Jprop, peak force, and mean force. Results suggest limited change in Jprop (g = 0.01-0.58), but back squats may potentiate RFD via the stretch-shortening cycle.

3.
J Strength Cond Res ; 36(7): 1875-1883, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32694287

RESUMO

ABSTRACT: Howe, LP, Bampouras, TM, North, JS, and Waldron, M. Improved ankle mobility after a 4-week training program affects landing mechanics: a randomized controlled trial. J Strength Cond Res 36(7): 1875-1883, 2022-This study examined the effects of a 4-week ankle mobility intervention on landing mechanics. Twenty subjects with restricted ankle dorsiflexion range of motion (DF ROM) were allocated to either a strength training only (n = 9) or a strength training and ankle mobility program (n = 11). Subjects performed a weight-bearing lunge test and bilateral drop-landings before and after the intervention. Normalized peak vertical ground reaction force (vGRF), time to peak vGRF, and loading rate were calculated, alongside sagittal-plane initial contact angles, peak angles, and sagittal-plane joint displacement for the ankle, knee, and hip. Frontal-plane projection angles were also calculated. After the intervention, only the strength and mobility group improved ankle DF ROM (mean difference = 4.1°, effect size [ES] = 1.00, p = 0.002). A one-way analysis of covariance found group effects for ankle joint angle at initial contact (p = 0.045), ankle (p < 0.001) and hip joint angle at peak flexion (p = 0.041), and sagittal-plane ankle (p < 0.001) and hip joint displacement (p = 0.024) during bilateral drop-landings. Post hoc analysis revealed that the strength and mobility group landed with greater ankle plantarflexion at initial contact (mean difference = 1.4 ± 2.0°, ES = 0.46) and ankle dorsiflexion at peak flexion (mean difference = 6.3 ± 2.9°, ES = 0.74) after the intervention, resulting in a greater ankle joint displacement (mean difference = 7.7 ± 4.0°, ES = 1.00). However, the strength training only group landed with increased peak hip flexion (mean difference = 14.4 ± 11.0°, ES = 0.70) and hip joint displacement (mean difference = 8.0 ± 6.6°, ES = 0.44) during post-testing. The findings suggest that changes in landing strategies following the performance of a strength training program are specific to whether restrictions in ankle mobility are considered as part of the intervention.


Assuntos
Articulação do Tornozelo , Tornozelo , Fenômenos Biomecânicos , Humanos , Articulação do Joelho , Amplitude de Movimento Articular
4.
Ergonomics ; 65(1): 147-158, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34319864

RESUMO

This study quantified the physiological and biomechanical effects of the 20 lb (9.07 kg, males) and 14 lb (6.35 kg, females) weighted vest used in CrossFit, and whether they were predisposed to injury. Twenty subjects (10 males, 10 females) undertook walking (0%, 5% and 10% gradient) and running trials in two randomised study visits (weighted vest/no weighted vest). Physiological demand during walking was increased with the vest at 10% but not 5% or 0% with no change in gait variables. In the running trial, the weighted vest increased oxygen uptake (males; females) (+0.22L/min, p < 0.01; +0.07 L/min, p < 0.05), heart rate (+11bpm, p < 0.01; +11bpm, p < 0.05), carbohydrate oxidation (+0.6 g/min, p < 0.001; +0.2 g/min, p < 0.01), and energy expenditure (+3.8 kJ/min, p < 0.001; +1.5 kJ/min, p < 0.05) whilst blood lactate was increased only in males (+0.6 mmol/L, p < 0.05). There was no change in stride length or frequency. Weighted vest training increases physiological stress and carbohydrate oxidation without affecting measured gait parameters. Practitioner summary: We examined the effect of weighted vest training prescribed in CrossFit (20 lb/9.07 kg, males and 14 lb/6.35 kg, females) in a randomised controlled trial. We found that physiological stress is increased in both sexes, although three-fold greater in males, but with no change in biomechanical gait that predisposes to lower-limb injury.


Assuntos
Marcha , Caminhada , Fenômenos Biomecânicos , Metabolismo Energético , Feminino , Frequência Cardíaca , Humanos , Masculino , Estresse Fisiológico
5.
J Sport Rehabil ; 30(6): 911-919, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33571960

RESUMO

CONTEXT: Ankle dorsiflexion range of motion (DF ROM) has been associated with a number of kinematic and kinetic variables associated with landing performance that increase injury risk. However, whether exercise-induced fatigue exacerbates compensatory strategies has not yet been established. OBJECTIVES: (1) Explore differences in landing performance between individuals with restricted and normal ankle DF ROM and (2) identify the effect of fatigue on compensations in landing strategies for individuals with restricted and normal ankle DF ROM. DESIGN: Cross-sectional. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twelve recreational athletes with restricted ankle DF ROM (restricted group) and 12 recreational athletes with normal ankle DF ROM (normal group). MAIN OUTCOME MEASURE(S): The participants performed 5 bilateral drop-landings, before and following a fatiguing protocol. Normalized peak vertical ground reaction force, time to peak vertical ground reaction force, and loading rate were calculated, alongside sagittal plane initial contact angles, peak angles, and joint displacement for the ankle, knee, and hip. Frontal plane projection angles were also calculated. RESULTS: At the baseline, the restricted group landed with significantly less knee flexion (P = .005, effect size [ES] = 1.27) at initial contact and reduced peak ankle dorsiflexion (P < .001, ES = 1.67), knee flexion (P < .001, ES = 2.18), and hip-flexion (P = .033, ES = 0.93) angles. Sagittal plane joint displacement was also significantly less for the restricted group for the ankle (P < .001, ES = 1.78), knee (P < .001, ES = 1.78), and hip (P = .028, ES = 0.96) joints. CONCLUSIONS: These findings suggest that individuals with restricted ankle DF ROM should adopt different landing strategies than those with normal ankle DF ROM. This is exacerbated when fatigued, although the functional consequences of fatigue on landing mechanics in individuals with ankle DF ROM restriction are unclear.


Assuntos
Tornozelo , Fadiga , Movimento , Amplitude de Movimento Articular , Tornozelo/fisiologia , Atletas , Fenômenos Biomecânicos , Estudos Transversais , Humanos
6.
J Strength Cond Res ; 34(2): 332-336, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31425458

RESUMO

Crowe, MA, Bampouras, TM, Small, K, and Howe, LP. Restricted unilateral ankle dorsiflexion movement increases interlimb vertical force asymmetries in bilateral bodyweight squatting. J Strength Cond Res 34(2): 332-336, 2020-The purpose of this study was to investigate the effect of unilateral restrictions in ankle-dorsiflexion range of motion (DF-ROM) on interlimb vertical ground reaction force (vGRF) asymmetries. Twenty healthy and physically active volunteers (age 23 ± 3 years; height 1.72 ± 0.1 m; mass 74.9 ± 20.3 kg) performed 3 barefoot bodyweight squats (control condition) and with a 10° custom-built forefoot wedge under the right foot to artificially imitate ankle DF-ROM restriction (wedge condition). Force data were used to calculate the mean asymmetry index score for the upper descent phase, lower descent phase, lower ascent phase, and upper ascent phase during the bilateral squat. Significant differences were found for comparisons for each phase between conditions, with effect sizes ranging between 0.7 and 1.1. Asymmetry index scores indicated that for all phases, the unrestricted limb in the wedge condition produced greater vGRF. Therefore, interlimb differences in ankle DF-ROM can cause interlimb asymmetries in vGRF during bilateral squatting. As such, athletes with asymmetrical squat mechanics should be screened for interlimb differences in ankle DF-ROM to ascertain whether it is a contributing factor.


Assuntos
Articulação do Tornozelo/fisiologia , Teste de Esforço , Amplitude de Movimento Articular/fisiologia , Adulto , Fenômenos Biomecânicos/fisiologia , Estudos Cross-Over , Humanos , Masculino , Adulto Jovem
7.
J Strength Cond Res ; 32(8): 2216-2220, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28301433

RESUMO

Bampouras, TM and Dewhurst, S. A comparison of bilateral muscular imbalance ratio calculations using functional tests. J Strength Cond Res 32(8): 2216-2220, 2018-Bilateral muscular imbalance can increase the risk of injury and negatively impact on sporting performance. Bilateral muscular imbalances are typically calculated as ([side 1 - side 2]/reference value) × 100, to provide a percentage value of the difference between limbs. Using different numerator (right-left or strong-weak) or reference values (left, right, strong, weak, average of the 2) could mask or inflate the true difference value. This study aimed to compare the bilateral muscular imbalance ratio calculations, using the absolute difference between limbs as the numerator and the 5 different options as reference values. Twenty-three males (21.6 ± 1.9 years, 1.80 ± 0.06 m, 80.5 ± 13.8 kg) and 11 females (20.8 ± 1.5 years, 1.62 ± 0.03 m, 68.0 ± 6.5 kg) performed the one-legged 6-m timed test and the one-legged triple-hop distance test. The 5 possible combinations were compared with a 2 (sex) × 2 (functional test) × 5 (calculation method) analysis of variance for each test. Significant differences (p ≤ 0.05) were found between sex when the right leg was used as the reference value (men: 6.1%, women: 9.1%), and within calculation methods for men (range: 5.9-6.5%) and women (range: 8.4-9.4%), with low effect sizes (range: 0.07-0.26). These findings demonstrate that using a different reference value for calculating bilateral muscular imbalances does not result in a practically significant difference. These findings can be used to inform a more standardized calculation method which will afford conditioning coaches a more correct evaluation and monitoring of training and rehabilitation programs.


Assuntos
Extremidade Inferior/fisiopatologia , Conceitos Matemáticos , Músculo Esquelético/fisiopatologia , Teste de Esforço , Feminino , Humanos , Masculino , Valores de Referência , Fatores Sexuais , Adulto Jovem
8.
Exp Brain Res ; 235(9): 2661-2668, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28578478

RESUMO

Dynamic balance control-characterised as movement of the trunk and lower limbs-was assessed during fixation of a fixed target, smooth pursuits and saccadic eye movements in ten young (22.9 ± 1.5 years) and ten older (72.1 ± 8.2 years) healthy females walking overground. Participants were presented with visual stimuli to initiate eye movements, and posture and gaze were assessed with motion analysis and eye tracking equipment. The results showed an increase in medial/lateral (ML) trunk movement (C7: p = 0.012; sacrum: p = 0.009) and step-width variability (p = 0.052) during smooth pursuits compared to a fixed target, with no changes for saccades compared to a fixed target. The elders demonstrated greater ML trunk movement (sacrum: p = 0.037) and step-width variability (p = 0.037) than the younger adults throughout, although this did not interact with the eye movements. The findings showed that smooth pursuits decreased balance control in young and older adults similarly, which was likely a consequence of more complicated retinal flow. Since healthy elders are typically already at a postural disadvantage, further decreases in balance caused by smooth pursuits are undesirable.


Assuntos
Envelhecimento/fisiologia , Percepção de Movimento/fisiologia , Equilíbrio Postural/fisiologia , Acompanhamento Ocular Uniforme/fisiologia , Movimentos Sacádicos/fisiologia , Tronco/fisiologia , Caminhada/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Medições dos Movimentos Oculares , Feminino , Humanos , Adulto Jovem
9.
Eur J Appl Physiol ; 117(10): 2039-2045, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28803367

RESUMO

PURPOSE: The biarticular rectus femoris (RF), operating on the ascending limb of the force-length curve, produces more force at longer lengths. However, experimental studies consistently report higher knee extension torque when supine (longer RF length) compared to seated (shorter RF length). Incomplete activation in the supine position has been proposed as the reason for this discrepancy, but differences in antagonistic co-activation could also be responsible due to altered hamstrings length. We examined the role of agonist and antagonist muscles in explaining the isometric knee extension torque variation with changes in hip joint angle. METHOD: Maximum voluntary isometric knee extension torque (joint MVC) was recorded in seated and supine positions from nine healthy males (30.2 ± 7.7 years). Antagonistic torque was estimated using EMG and added to the respective joint MVC (corrected MVC). Submaximal tetanic stimulation quadriceps torque was also recorded. RESULT: Joint MVC was not different between supine (245 ± 71.8 Nm) and seated (241 ± 69.8 Nm) positions and neither was corrected MVC (257 ± 77.7 and 267 ± 87.0 Nm, respectively). Antagonistic torque was higher when seated (26 ± 20.4 Nm) than when supine (12 ± 7.4 Nm). Tetanic torque was higher when supine (111 ± 31.9 Nm) than when seated (99 ± 27.5 Nm). CONCLUSION: Antagonistic co-activation differences between hip positions do not account for the reduced MVC in the supine position. Rather, reduced voluntary knee extensor muscle activation in that position is the major reason for the lower MVC torque when RF is lengthened (hip extended). These findings can assist standardising muscle function assessment and improving musculoskeletal modelling applications.


Assuntos
Contração Isométrica , Articulação do Joelho/fisiologia , Joelho/fisiologia , Músculo Esquelético/fisiologia , Adulto , Humanos , Masculino , Torque
10.
J Appl Biomech ; 32(4): 415-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26959196

RESUMO

Leg stiffness is an important performance determinant in several sporting activities. This study evaluated the criterion-related validity and reliability of 2 field-based leg stiffness devices, Optojump NextR (Optojump) and Myotest ProR (Myotest) in different testing approaches. Thirty-four males performed, on 2 separate sessions, 3 trials of 7 maximal hops, synchronously recorded from a force platform (FP), Optojump and Myotest. Validity (Pearson's correlation coefficient, r; relative mean bias; 95% limits of agreement, 95%LoA) and reliability (coefficient of variation, CV; intraclass correlation coefficient, ICC; standard error of measurement, SEM) were calculated for first attempt, maximal attempt, and average across 3 trials. For all 3 methods, Optojump correlated highly to the FP (range r = .98-.99) with small bias (range 0.91-0.92, 95%LoA 0.86-0.98). Myotest demonstrated high correlation to FP (range r = .81-.86) with larger bias (range 1.92-1.93, 95%LoA 1.63-2.23). Optojump yielded a low CV (range 5.9% to 6.8%), high ICC (range 0.82-0.86), and SEM ranging 1.8-2.1 kN/m. Myotest had a larger CV (range 8.9% to 13.0%), moderate ICC (range 0.64-0.79), and SEM ranging from 6.3 to 8.9 kN/m. The findings present important information for these devices and support the use of a time-efficient single trial to assess leg stiffness in the field.


Assuntos
Desempenho Atlético/fisiologia , Teste de Esforço/instrumentação , Extremidade Inferior/fisiopatologia , Músculo Esquelético/fisiopatologia , Humanos , Masculino , Movimento/fisiologia , Reprodutibilidade dos Testes , Equipamentos Esportivos , Adulto Jovem
11.
J Aging Phys Act ; 23(1): 128-32, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24515979

RESUMO

Physical activity assists older individuals' functional ability and postural stability. Recently, Scottish country dance (SCD) was reported as being a beneficial form of physical activity for functional ability in older females. This study aims to examine the effect of SCD on postural stability. Scottish country dancers (n = 20) were compared with physically active controls (n = 33) for static postural sway measured on a force platform. The Romberg and Tandem stances were used under 'eyes open' and 'eyes closed' conditions. Ninety-five percent ellipse area and sway velocity were calculated from the center of pressure displacement. Ninety-five percent ellipse area was the same for both groups in all tests. The control group had greater sway velocity for all tests (P < .01) except Tandem eyes closed. SCD participation resulted in similar postural sway as participation in other physical activities, however nondancers may need a greater amount of regulatory activity to maintain balance.


Assuntos
Envelhecimento/fisiologia , Dança/fisiologia , Atividade Motora/fisiologia , Equilíbrio Postural/fisiologia , Fatores Etários , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Escócia
12.
J Aging Phys Act ; 22(1): 146-53, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23538484

RESUMO

The effects of long-term participation in Scottish country dance on body composition, functional ability, and balance in healthy older females were examined. Participants were grouped into dancers and physically active nondancers (ages 60-70 and 70-80 for both groups). Physical activity, body composition (body-mass index, skinfold thickness, waist-to-hip ratio), functional ability (6-min walk distance, 6-m walk time, 8-ft up-and-go time, lower body flexibility, shoulder flexibility), and static balance were measured. Younger dancers and physically active nondancers had similar 6-min walk distance, 6-m walk time, and 8-ft up-and-go time results; however, while older dancers performed similarly to younger dancers, older physically active nondancers performed poorer than their younger counterparts (p < .05). Body composition and static balance were the same for all groups. Regular physical activity can maintain body composition and postural stability with advancing age; however, Scottish country dance can delay the effects of aging on locomotion-related functional abilities.


Assuntos
Envelhecimento , Dança/fisiologia , Aptidão Física , Fatores Etários , Idoso , Envelhecimento/etnologia , Envelhecimento/fisiologia , Envelhecimento/psicologia , Composição Corporal , Índice de Massa Corporal , Feminino , Avaliação Geriátrica/métodos , Humanos , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Aptidão Física/fisiologia , Aptidão Física/psicologia , Equilíbrio Postural , Amplitude de Movimento Articular , Projetos de Pesquisa , Escócia/epidemiologia , Dobras Cutâneas , Tempo , Relação Cintura-Quadril
13.
J Strength Cond Res ; 28(5): 1381-5, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24755869

RESUMO

Strength assessment is often part of the objective periodical observation of teams, squads, or large groups of athletes. Equipment that provides assessment that is mobile and is easy to use will reduce the impact on the athletes' training and competitive calendar. However, any equipment used must be reliable to allow accurate monitoring of performance. The aim of this study was to examine the reliability of the Concept2 Dyno dynamometer. Forty-six competitive athletes (males: n = 36, age 23.3 ± 6.8 years, height 1.80 ± 0.09 m, body mass 82.3 ± 15.6 kg; females, n = 10, age 20.7 ± 1.4 years, height 1.65 ± 0.09 m, body mass 62.7 ± 11.8 kg), with a strength training background of more than 2 years, performed a familiarization session and 3 experimental sessions with 1 week intervening each. Each experimental session consisted of 3 maximal efforts of seated chest press (CPress), seated row (SRow), and seated leg press (LPress) exercises. Reliability was assessed examining systematic bias, intraclass correlation coefficient, coefficient of variation (CV), and 95% limits of agreement (95% LoA) between sessions. No systematic bias was found for any of the exercises. Intraclass correlation coefficients were high (0.89-0.98) with relatively low CV (6.2-4.3%). Finally, 95% LoA indicated that subsequent testing could underestimate by a factor of 0.87 or overestimate by a factor of 1.17, on average. These results indicate that Concept2 Dyno dynamometer is reliable and can be used in the field to efficiently monitor strength performance. Coaches and researchers should use "analytical goals" to help decide as to the use of Concept2 Dyno for their purposes.


Assuntos
Teste de Esforço/instrumentação , Dinamômetro de Força Muscular/normas , Força Muscular , Adolescente , Adulto , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Reprodutibilidade dos Testes , Treinamento Resistido , Adulto Jovem
14.
Amino Acids ; 44(2): 555-61, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22855206

RESUMO

Limited research examining the effect of taurine (TA) ingestion on human exercise performance exists. The aim of this study was to investigate the effect of acute ingestion of 1,000 mg of TA on maximal 3-km time trial (3KTT) performance in trained middle-distance runners (MDR). Eight male MDR (mean ± SD: age 19.9 ± 1.2 years, body mass 69.4 ± 6.6 kg, height 180.5 ± 7.5 cm, 800 m personal best time 121.0 ± 5.3 s) completed TA and placebo (PL) trials 1 week apart in a double-blind, randomised, crossover designed study. Participants consumed TA or PL in capsule form on arrival at the laboratory followed by a 2-h ingestion period. At the end of the ingestion period, participants commenced a maximal simulated 3KTT on a treadmill. Capillary blood lactate was measured pre- and post-3KTT. Expired gas, heart rate (HR), ratings of perceived exertion (RPE), and split times were measured at 500-m intervals during the 3KTT. Ingestion of TA significantly improved 3KTT performance (TA 646.6 ± 52.8 s and PL 658.5 ± 58.2 s) (p = 0.013) equating to a 1.7 % improvement (range 0.34-4.24 %). Relative oxygen uptake, HR, RPE and blood lactate did not differ between conditions (p = 0.803, 0.364, 0.760 and 0.302, respectively). Magnitude-based inference results assessing the likeliness of a beneficial influence of TA were 99.3 %. However, the mechanism responsible for this improved performance is unclear. TA's potential influence on exercise metabolism may involve interaction with the muscle membrane, the coordination or the force production capability of involved muscles. Further research employing more invasive techniques may elucidate TA's role in improving maximal endurance performance.


Assuntos
Corrida/fisiologia , Taurina/metabolismo , Adulto , Ingestão de Alimentos , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio , Resistência Física , Adulto Jovem
15.
J Strength Cond Res ; 27(11): 2997-3000, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23442291

RESUMO

Postactivation potentiation (PAP) refers to increased muscular force generation after previous muscular activity. Various studies have used different squat variations as a PAP stimulus; however, different squat depths can have different mechanical and physiological demands that could yield different PAP levels and subsequent performance. The study aimed to compare the effects of the parallel (PS) and quarter (QS) squat on PAP. Twenty-seven, semiprofessional, male rugby union players (mean ± SD, 18 ± 2 years, 87.2 ± 5.4 kg, 180.7 ± 5.1 cm) performed a countermovement jump (BL-CMJ) followed by a 10-minute rest. Subsequently, they performed 3 PS or QS, at each squat's respective 3-repetition maximum load, in a randomized counterbalanced order. After a 5-minute rest, another countermovement jump (CMJ) was performed (POST-CMJ). Countermovement jump height (JH), peak power (PP), impulse (I), and flight time (FT) were recorded using a contact mat. BL-CMJ and POST-CMJ pairwise comparisons for all variables were conducted for each squat type to examine performance changes. Delta values were compared to examine whether one squat produced better CMJ results. Both squats induced PAP for all the variables (p < 0.05), although PS produced better results than QS (p < 0.05; JH, 4.6 ± 2 vs. 3.5 ± 2 cm; I, 15 ± 6 vs. 12 ± 5 N·s; PP, 285 ± 109 vs. 215 ± 96 W; FT, 34 ± 23 vs. 26 ± 11 milliseconds for PS vs. QS). This is the first study to demonstrate that different squat types can induce PAP and that PS is more beneficial for subsequent CMJ performance compared with QS. It is suggested that the deeper depth of PS, which increases gluteus maximum activation and work produced, is responsible for the increased CMJ performance.


Assuntos
Teste de Esforço/métodos , Movimento/fisiologia , Força Muscular , Músculo Esquelético/fisiologia , Adolescente , Adulto , Humanos , Extremidade Inferior/fisiologia , Masculino , Contração Muscular , Adulto Jovem
16.
Atten Percept Psychophys ; 85(6): 1905-1919, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37495933

RESUMO

During multisensory integration, the time range within which visual and auditory information can be perceived as synchronous and bound together is known as the temporal binding window (TBW). With increasing age, the TBW becomes wider, such that older adults erroneously, and often dangerously, integrate sensory inputs that are asynchronous. Recent research suggests that attentional cues can narrow the width of the TBW in younger adults, sharpening temporal perception and increasing the accuracy of integration. However, due to their age-related declines in attentional control, it is not yet known whether older adults can deploy attentional resources to narrow the TBW in the same way as younger adults. This study investigated the age-related changes to the attentional modulation of the TBW. Thirty younger and 30 older adults completed a cued-spatial-attention version of the stream-bounce illusion, assessing the extent to which the visual and auditory stimuli were integrated when presented at three different stimulus-onset asynchronies, and when attending to a validly cued or invalidly cued location. A 2 × 2 × 3 mixed ANOVA revealed that when participants attended to the validly cued location (i.e., when attention was present), susceptibility to the stream-bounce illusion decreased. However, crucially, this attentional manipulation significantly affected audiovisual integration in younger adults, but not in older adults. These findings suggest that older adults have multisensory integration-related attentional deficits. Directions for future research and practical applications surrounding treatments to improve the safety of older adults' perception and navigation through the environment are discussed.


Assuntos
Ilusões , Percepção Visual , Humanos , Idoso , Atenção , Sinais (Psicologia) , Estimulação Acústica , Percepção Auditiva , Estimulação Luminosa
17.
BMJ Open ; 13(11): e075113, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37949619

RESUMO

BACKGROUND: Training programmes for obstetrics and gynaecology (O&G) and general surgery (GS) vary significantly, but both require proficiency in laparoscopic skills. We sought to determine performance in each specialty. DESIGN: Prospective, observational study. SETTING: Health Education England North-West, UK. PARTICIPANTS: 47 surgical trainees (24 O&G and 23 GS) were subdivided into four groups: 11 junior O&G, 13 senior O&G, 11 junior GS and 12 senior GS trainees. OBJECTIVES: Trainees were tested on four simulated laparoscopic tasks: laparoscopic camera navigation (LCN), hand-eye coordination (HEC), bimanual coordination (BMC) and suturing with intracorporeal knot tying (suturing). RESULTS: O&G trainees completed LCN (p<0.001), HEC (p<0.001) and BMC (p<0.001) significantly slower than GS trainees. Furthermore, O&G found fewer number of targets in LCN (p=0.001) and dropped a greater number of pins than the GS trainees in BMC (p=0.04). In all three tasks, there were significant differences between O&G and GS trainees but no difference between the junior and senior groups within each specialty. Performance in suturing also varied by specialty; senior O&G trainees scored significantly lower than senior GS trainees (O&G 11.4±4.4 vs GS 16.8±2.1, p=0.03). Whilst suturing scores improved with seniority among O&G trainees, there was no difference between the junior and senior GS trainees (senior O&G 11.4±4.4 vs junior O&G 3.6±2.1, p=0.004). DISCUSSION: GS trainees performed better than O&G trainees in core laparoscopic skills, and the structure of O&G training may require modification. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT05116332).


Assuntos
Cirurgia Geral , Ginecologia , Laparoscopia , Humanos , Ginecologia/educação , Estudos Prospectivos , Competência Clínica , Inglaterra , Educação em Saúde , Laparoscopia/educação , Técnicas de Sutura , Cirurgia Geral/educação
18.
Ann Surg Open ; 4(2): e284, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37342254

RESUMO

Introduction: Surgeons are among the most at-risk professionals for work-related musculoskeletal decline and experience high mental demands. This study examined the electromyographic (EMG) and electroencephalographic (EEG) activities of surgeons during surgery. Methods: Surgeons who performed live laparoscopic (LS) and robotic (RS) surgeries underwent EMG and EEG measurements. Wireless EMG was used to measure muscle activation in four muscle groups bilaterally (biceps brachii, deltoid, upper trapezius, and latissimus dorsi), and an 8-channel wireless EEG device was used to measure cognitive demand. EMG and EEG recordings were completed simultaneously during (i) noncritical bowel dissection, (ii) critical vessel dissection, and (iii) dissection after vessel control. Robust ANOVA was used to compare the %MVCRMS and alpha power between LS and RS. Results: Thirteen male surgeons performed 26 laparoscopic surgeries (LS) and 28 robotic surgeries (RS). Muscle activation was significantly higher in the right deltoid (p = 0.006), upper trapezius (left, p = 0.041; right, p = 0.032), and latissimus dorsi (left, p = 0.003; right, p = 0.014) muscles in the LS group. There was greater muscle activation in the right biceps than in the left biceps in both surgical modalities (both p = 0.0001). There was a significant effect of the time of surgery on the EEG activity (p <0.0001). A significantly greater cognitive demand was observed in the RS than in the LS with alpha, beta, theta, delta, and gamma (p = 0.002 - p <0.0001). Conclusion: These data suggest greater muscle demands in laparoscopic surgery, but greater cognitive demands in robotic surgery.

19.
J Bodyw Mov Ther ; 31: 62-71, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35710223

RESUMO

OBJECTIVE: To investigate the effect of disk training and tape application on diminished proprioception after Lateral Ankle Sprain (LAS) in active populations. ELIGIBILITY CRITERIA: Only clinical trials investigating the effectiveness of disk training and ankle tape on proprioception deficits following LAS by assessing JPS or kinaesthesia were included. INFORMATION SOURCES: Electronic databases of PubMed, MEDLINE, SPORTDiscus, CINAHL, Web of Science, Cochrane and PEDro were searched. The main search was conducted in February 2022. RISK OF BIAS: The physiotherapy Evidence Database (PEDro) scale was utilised to assess the methodological quality of each article. RESULT: The search yielded six studies investigating the effects of disk training and four studies investigating the effects of inelastic tape. Five articles showed a significant improvement on JPS after disk training. However, no difference across different intervention groups was observed in one study. Only one trial presented an immediate significant improvement when taped, while another study showed that external ankle supports significantly improved JPS after 2 weeks and after 2 months. Three of four studies found no immediate improvement on proprioceptive deficits by the use of tape. CONCLUSIONS: This review found that disk training may improve impaired proprioception after LAS, whilst the efficacy of inelastic tape was not evident due to methodological quality of the few available studies. Further studies are needed to establish whether these interventions can be used clinically with sufficient evidence.


Assuntos
Traumatismos do Tornozelo , Tornozelo , Traumatismos do Tornozelo/terapia , Articulação do Tornozelo , Humanos , Modalidades de Fisioterapia , Propriocepção
20.
J Gastrointest Surg ; 26(7): 1520-1530, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35426034

RESUMO

BACKGROUND: Surgeons are among the most at risk of work-related musculoskeletal health decline because of the physical demands of surgery, which is also associated with cognitive fatigue. Minimally invasive surgery offers excellent benefits to patients but the impact of robotic or laparoscopic surgery on surgeon well-being is less well understood. This work examined the musculoskeletal and cognitive demands of robot-assisted versus standard laparoscopic surgery. METHODS: Medline, Embase and Cochrane databases were systematically searched for 'Muscle strain' AND 'musculoskeletal fatigue' AND 'occupational diseases' OR 'cognitive fatigue' AND 'mental fatigue' OR 'standard laparoscopic surgery' AND 'robot-assisted laparoscopic surgery'. Primary outcomes measured were electromyographic (EMG) activity for musculoskeletal fatigue and questionnaires (NASA-TLX, SMEQ, or Borg CR-10) for cognitive fatigue. A systematic review was conducted in accordance with the Synthesis Without Meta-analysis (SWiM) Guidelines. The study was preregistered on Prospero ID: CRD42020184881. RESULTS: Two hundred and ninety-eight original titles were identified. Ten studies that were all observational studies were included in the systematic review. EMG activity was consistently lower in robotic than in laparoscopic surgery in the erector spinae and flexor digitorum muscles but higher in the trapezius muscle. This was associated with significantly lower cognitive load in robotic than laparoscopic surgery in 7 of 10 studies. CONCLUSIONS: Evidence suggests a reduction in musculoskeletal demands during robotic surgery in muscles excluding the trapezius, and this is associated with most studies reporting a reduced cognitive load. Robotic surgery appears to have less negative cognitive and musculoskeletal impact on surgeons compared to laparoscopic surgery.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgiões , Cognição , Humanos , Laparoscopia/efeitos adversos , Procedimentos Cirúrgicos Robóticos/efeitos adversos
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