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The Effects of Load and Effort-Matched Concentric and Eccentric Knee Extension Training in Recreational Females

100%
Fisher J., Langford C.
Human Movement
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2014
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vol. 15
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issue 3
147-151
EN
Purpose. The purpose of this study was to compare the effects of load and intensity of effort-matched concentric and eccentric knee extension training on isometric strength. Methods. Unilateral isometric torque was measured using a MedX knee extension after which eleven recreationally trained females performed both concentric-only (CONC) and eccentric-only (ECC) unilateral knee extension exercise once per week for 8 weeks. Participants performed a single set of both CONC and ECC exercise loadmatched at 80% of maximum isometric torque for each condition. All participants exercised to repetition maximum in both CONC and ECC conditions at a pace of ~3 s duration for each muscle action. This ensured that participants exercised to the same intensity of effort for both CONC and ECC training interventions. Results. Analyses revealed significant increases in isometric torque for both CONC (14.8%) and ECC (13.0%) conditions (p < 0.05). Absolute change from pre- to post-intervention was compared for CONC and ECC training conditions revealing no statistically significant differences (p > 0.05). Effect sizes are reported as 0.60 (CONC) and 0.53 (ECC). In addition, analyses revealed significantly greater mean total training volume for ECC compared with CONC conditions (15903 vs. 8091, respectively; p < 0.001). Conclusions. The present findings indicate that, when matched for intensity of effort, both CONC and ECC knee extension exercise can significantly improve strength to the same extent. This supports previous research that load and repetitions are not as important as intensity of effort in resistance exercise.
2
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Influence of Static Stretching Duration on Quadriceps Force Development and Eletromyographic Activity

88%
Rossi L., Pereira R., Simão R., Brandalize M., Gomes A.
Human Movement
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2010
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vol. 11
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issue 2
137-143
EN
Purpose. The purpose of the present study was to analyze the influence of static stretching duration on quadriceps muscle isometric force and electromyographic (EMG) activity of the rectus femoris and vastus lateralis. Basic procedures. Twenty recreationally-active healthy men were selected for the study. On two separate days, participants took part in two stretching protocols of different durations. Following a specific warmup, participants performed isometric strength assessments of the dominant leg before and after a bout of quadriceps stretching. The stretching protocol consisted of two stretches for the quadriceps muscle for three repetitions of 30 seconds on one visit, and 60 seconds on the other. Main findings. The results revealed a significant reduction in quadriceps muscle mean and peak forces and EMG activity for the rectus femoris with both 30- and 60-second stretching protocols (p ≤ 05). However, EMG activity of the vastus lateralis decreased significantly only in the 60-second protocol (p ≤ 05). Conclusions. Both stretching protocols induced significant decreases in strength and EMG activity, although the stretching duration (60 × 30) did not appear to be a major influencing factor for the current strength reductions. In this perspective, coaches and athletes should avoid flexibility training which consists in stretching repetitions of 30 seconds or longer prior to competitions.
3
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Isometric torque of arm abduction and adduction muscles in men

75%
Dulawski G., Bober T., Czamara A., Zaleski A.
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2008
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vol. 16
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issue 2
13-18
PL
Przedmiotem pracy były pomiary statycznych momentów sił grup mięśni odwodzących i przywodzących ramię (w płasz-czyźnie czołowej). Badania wykonano na urządzeniu Biodex Medical System Pro 3 u 15 mężczyzn praworęcznych. Pomiary maksymalnych momentów sił w 5 wybranych pozycjach kątowych pomiędzy 0° (ramię wzdłuż tułowia) a 120° (dla obu kierunków) pozwoliły przebiegi moment-kąt opisać wielomianami drugiego stopnia. Przebieg momentu siły mięśni odwodzących ramię w funkcji kąta ma kształt hiperboli z maksimum przy kącie 0°, a dla mięśni przywodzących przyjmuje kształt paraboli z maksimum przy kącie 45°. Grupa mięśni odwodzących wyzwala większy moment siły od przywodzacych przy kącie 0° i 120°. W pozostałych, pośrednich, pozycjach kątowych jest niewielka przewaga mięśni przywodzą-cych nad odwodzącymi.
EN
The aim of work was to present the results of maximal (isometric) torque produced by muscles acting as arm abductors and adductors (frontal plane). The Biodex Medical System was applied to test the group of 15, right handed, young men. Torque was measured at 5 different angular positions between 0° (arm along the trunk) and 120° in both directions. The torque-angle curves were approximated with polynomial of the second order. The abduction torque-angle curve has a shape of hyperbola with maximum at 0° and adduction torque has a form of parabola with maximum at 45°. Abduction muscle group is stronger than adduction muscle group in the position of 0° and 120°. In the remaining positions the adduction muscle group is stronger than abduction muscle group.
4
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Evaluation of Consecutive Maximum Contractions as a Test of Neuromuscular Function

75%
Suzovic D., Nedeljkovic A., Pazin N., Planic N., Jaric S.
Journal of Human Kinetics
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2008
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vol. 20
51-61
EN
The aim of the study was to conduct a preliminary evaluation of consecutive maximum contractions (CMC) as a test of neuromuscular function. Eleven participants performed externally paced isometric CMC (i.e., a series of consecutive maximum force exertions and relaxations) of the quadriceps muscle. The derived variables included the peak forces, and the maximum rates of force development and relaxation. The results revealed high within-day reliability of CMC variables, while their correlations with the jumping performance were consistently higher than those of the variables of the standard strength test (SST). CMC variables also showed fairly stable values across a wide range of frequencies, while their peak force revealed a strong relationship with maximum force of SST despite being about considerably lower. Therefore, we conclude that CMC could be developed into a standard test of neuromuscular function. In addition to capturing the muscle actions based on different neural activation pattern than SST, CMC could also be based on simpler testing procedure, lower force exertion, and self-selected frequencies.
5
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Length-Weight Relationship and Catch Size of Bigeye Tuna (Thunnus obesus) Landed in Benoa, Bali, Indonesia

75%
Ahmad F., Dewanti L. P., Arnenda G. L., Rizal A.
World News of Natural Sciences
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2019
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vol. 23
34-42
EN
The research was conducted at the Tuna Fisheries Research Station, Denpasar, Bali, in July 2018 (3 weeks duration). There were several types of high-value fish incorporated into this research: tuna, skipjack, shrimp, cob, mackerel, snapper, squid, reef fish (grouper, baronang, lobster / barong shrimp) and ornamental fish. Seaweed processing was also assessed. Benoa Fishing Port is one of the tuna landing base bases in Indonesia. It is the main port in Bali Province and ranks beside Muara Baru (Jakarta), Pelabuhan Ratu (West Java) and Cilacap (Central Java). This research aim to identified length-weight relationship, and proportion of proper catch size of bigeye tuna. Herein, bigeye tuna (Thunnus obesus) was identified visually and then assessed. The first identifier is the large size of the eye. The growth pattern of big eye tuna (Thunnus obesus) landed in Benoa Fishing Portis is isometric, where the length increase is equal to weight gain (isometric positive). The length distribution of big eye tuna was in range of 81-170 cm FL (334 fishes are obtained), and the distribution of weights varied in size from 11-95 kg, with the most common catch size being in the range of 16-20 kg (95 fishes). Of note, 60% of the fish had not reached the proper catch size.
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