Effect of combined variation of force amplitude and rate of force development on the modulation characteristics of muscle activation during rapid isometric aiming force production

During many movements (e.g., running, jumping, and kicking) there is little time for skeletal muscles to build up force, thus rapid force development is important. The length dependency of isometric force development was investigated in maximally activated rat medial gastrocnemius muscles in situ with intact blood flow at 35 °C. Depending on time available for muscle activation, the length dependency of force development was expected to differ from that of the maximal isometric force (Fmax) reached much later during the contraction. During isometric force development in intact muscle–tendon preparations, the contractile elements actually shortened. Therefore, similar to previous findings on shortening contractions, it was hypothesized that maximal rate of force development (MRFD) would be obtained at a length below the optimum (Lo) for maximal isometric force production. To measure the effect of the entire time history of activation, force time integrals (FTIs) for different activation times (10–50 ms) were also calculated. The highest MRFD was obtained 1.94 ± 0.42 mm below (p < 0.05) Lo. When expressed relative to Fmax obtained at each individual length, the optimum was found at Lo – 4.4 mm. For FTI 10 ms and FTI 20 ms, optimum length was obtained at ~2 and 1 mm above (p < 0.05) Lo, respectively, whereas the optima for FTI 30, 40, and 50 ms were ~1 mm below (p < 0.05) Lo. In addition, at short lengths (< Lo – 4 mm) and for all activation times FTIs were relatively more decreased than Fmax. In conclusion, length dependency of force output during rapid force development differed from that of maximal isometric force; specifically, MRFD was obtained 2 mm below Lo.

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The Optimal Joint Angle for Adductor Pollicis Force Production in Men and Women

Canadian Journal of Applied Physiology ◽

10.1139/h99-038 ◽

1999 ◽

Vol 24 (6) ◽

pp. 570-580 ◽

Cited By ~ 6

Author(s):

David Ditor ◽

Audrey Hicks

Keyword(s):

Gender Difference ◽

Key Words ◽

Joint Angle ◽

Force Production ◽

Adductor Pollicis ◽

Rate Of Force Development ◽

Men And Women ◽

Twitch Force ◽

Force Development ◽

Nondominant Hand

The purpose of this study was to determine the joint angle that allows for the greatest MVC and evoked twitch forces from the adductor pollicis (AP), and also whether there is a gender difference in either the above forces or the optimum thumb angle. Ten men (25.2 yrs) and 10 women (27.6 yrs) participated. The nondominant hand was placed palm-down with the thumb fixed at four angles of abduction (55, 70, 85, 100°). Male MVC forces were significantly greater than female, and there was no significant effect of joint angle on MVC force in either gender. For the evoked twitch, men were significantly stronger than women when tested at the 100 and 85° angles, and a significant effect was found for joint angle such that the lowest twitch force occurred at 55°. Men also tended to have a greater rate of force development than women (p = 0.07). These data suggest that studies using the AP muscle in stimulated and voluntary paradigms should use a thumb angle between 70 and 100° of abduction, or approximately 85°, and that the same angle can be used for both men and women. Key words: evoked twitch, MVC, gender, EMG, rate of force development

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Specific cerebellar regions are related to force amplitude and rate of force development

NeuroImage ◽

10.1016/j.neuroimage.2011.09.019 ◽

2012 ◽

Vol 59 (2) ◽

pp. 1647-1656 ◽

Cited By ~ 27

Author(s):

M.B. Spraker ◽

D.M. Corcos ◽

A.S. Kurani ◽

J. Prodoehl ◽

S.P. Swinnen ◽

...

Keyword(s):

Rate Of Force Development ◽

Force Amplitude ◽

Force Development

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Evaluation of Strength and Muscle Activation Indicators in Sticking Point Region of National-Level Paralympic Powerlifting Athletes

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk6020043 ◽

2021 ◽

Vol 6 (2) ◽

pp. 43

Author(s):

Felipe J. Aidar ◽

Filipe Manuel Clemente ◽

Dihogo Gama de Matos ◽

Anderson Carlos Marçal ◽

Raphael Fabrício de Souza ◽

...

Keyword(s):

Muscle Activation ◽

Isometric Force ◽

National Level ◽

Rate Of Force Development ◽

Static Test ◽

Force Development ◽

Intermediate Phases ◽

Maximum Isometric Force ◽

Dynamic Time ◽

Sticking Point

Background: The sticking region is considered an intervening factor in the performance of the bench press with high loads. Objective: To evaluate the strength indicators in the sticking point region in Powerlifting Paralympic athletes. Methods: Twelve Brazilian Powerlifting Paralympic athletes performed maximum isometric force (MIF), rate of force development (RFD), time at MIF, velocity, dynamic time in sticking, and surface electromyography in several distances from the bar to the chest. Results: For velocity, there was a difference between the pre-sticking and sticking region (1.98 ± 0.32 and 1.30 ± 0.43, p = 0.039) and dynamic time between the pre-sticking and the sticking region (0.40 ± 0.16 and 0.97 ± 0.37, p = 00.021). In static test for the MIF, differences were found between 5.0 cm and 15.0 cm (CI 95% 784; 1088; p = 0.010) and between 10.0 cm and 5.0 cm (CI 95% 527; 768; p < 0.001). Regarding the RFD, differences were found (CI 95% 938; 1240; p = 0.004) between 5.0 cm and 25.0 cm and between 10.0 cm and 25.0 cm (CI 95% 513; 732; p < 0.001). In relation to time, there were differences between 5.0 cm and 15.0 cm (CI 95% 0.330; 0.515; p < 0.001), 5.0 cm, and 25.0 cm (CI 95% 0.928; 1.345; p = 0.001), 10.0 cm and 15.0 cm (p < 0.05) and 15.0 cm and 25.0 cm (p < 0.05). No significant differences were observed between the muscles in electromyography, although the triceps showed the highest muscle activation values. Conclusions: The maximum isometric force, rate of force development, time, velocity, and dynamic time had lower values, especially in the initial and intermediate phases in the sticking region.

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The differential effect of metabolic alkalosis on maximum force and rate of force development during repeated, high-intensity cycling

Journal of Applied Physiology ◽

10.1152/japplphysiol.00688.2013 ◽

2013 ◽

Vol 115 (11) ◽

pp. 1634-1640 ◽

Cited By ~ 10

Author(s):

Jason C. Siegler ◽

Paul W. M. Marshall ◽

Sean Raftry ◽

Cristy Brooks ◽

Ben Dowswell ◽

...

Keyword(s):

Sodium Bicarbonate ◽

High Intensity ◽

Differential Effect ◽

Force Production ◽

Rate Of Force Development ◽

Maximum Force ◽

Whole Body ◽

Peak Power Output ◽

Force Development ◽

Maximal Force

The purpose of this investigation was to assess the influence of sodium bicarbonate supplementation on maximal force production, rate of force development (RFD), and muscle recruitment during repeated bouts of high-intensity cycling. Ten male and female ( n = 10) subjects completed two fixed-cadence, high-intensity cycling trials. Each trial consisted of a series of 30-s efforts at 120% peak power output (maximum graded test) that were interspersed with 30-s recovery periods until task failure. Prior to each trial, subjects consumed 0.3 g/kg sodium bicarbonate (ALK) or placebo (PLA). Maximal voluntary contractions were performed immediately after each 30-s effort. Maximal force (Fmax) was calculated as the greatest force recorded over a 25-ms period throughout the entire contraction duration while maximal RFD (RFDmax) was calculated as the greatest 10-ms average slope throughout that same contraction. Fmax declined similarly in both the ALK and PLA conditions, with baseline values (ALK: 1,226 ± 393 N; PLA: 1,222 ± 369 N) declining nearly 295 ± 54 N [95% confidence interval (CI) = 84–508 N; P < 0.006]. RFDmax also declined in both trials; however, a differential effect persisted between the ALK and PLA conditions. A main effect of condition was observed across the performance time period, with RFDmax on average higher during ALK (ALK: 8,729 ± 1,169 N/s; PLA: 7,691 ± 1,526 N/s; mean difference between conditions 1,038 ± 451 N/s, 95% CI = 17–2,059 N/s; P < 0.048). These results demonstrate a differential effect of alkalosis on maximum force vs. maximum rate of force development during a whole body fatiguing task.

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The effect of rate of force development on maximal force production: acute and training-related aspects

European Journal of Applied Physiology ◽

10.1007/s00421-006-0380-9 ◽

2007 ◽

Vol 99 (6) ◽

pp. 605-613 ◽

Cited By ~ 53

Author(s):

Andreas Holtermann ◽

Karin Roeleveld ◽

Beatrix Vereijken ◽

Gertjan Ettema

Keyword(s):

Force Production ◽

Rate Of Force Development ◽

Force Development ◽

Maximal Force ◽

And Training

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Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

Journal of Human Kinetics ◽

10.1515/hukin-2015-0042 ◽

2015 ◽

Vol 46 (1) ◽

pp. 139-148 ◽

Cited By ~ 14

Author(s):

María Asunción Martínez-Valencia ◽

Salvador Romero-Arenas ◽

José L.L. Elvira ◽

José María González-Ravé ◽

Fernando Navarro-Valdivielso ◽

...

Keyword(s):

Repeated Measures ◽

Training Stimulus ◽

Force Production ◽

Sprint Performance ◽

Peak Force ◽

Rate Of Force Development ◽

Sprint Training ◽

Force Output ◽

Acceleration Phase ◽

Force Development

AbstractResisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001) in sprint times (20 and 30 m sprint) for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s−1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s−1, p ≤ 0.01). Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

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Training-induced changes in muscle CSA, muscle strength, EMG, and rate of force development in elderly subjects after long-term unilateral disuse

Journal of Applied Physiology ◽

10.1152/japplphysiol.01307.2003 ◽

2004 ◽

Vol 97 (5) ◽

pp. 1954-1961 ◽

Cited By ~ 172

Author(s):

Charlotte Suetta ◽

Per Aagaard ◽

Anna Rosted ◽

Ane K. Jakobsen ◽

Benn Duus ◽

...

Keyword(s):

Muscle Strength ◽

Strength Training ◽

Muscle Mass ◽

Muscle Activation ◽

Muscle Force ◽

Rate Of Force Development ◽

Muscle Size ◽

Elderly Subjects ◽

Force Development

The ability to develop muscle force rapidly may be a very important factor to prevent a fall and to perform other tasks of daily life. However, information is still lacking on the range of training-induced neuromuscular adaptations in elderly humans recovering from a period of disuse. Therefore, the present study examined the effect of three types of training regimes after unilateral prolonged disuse and subsequent hip-replacement surgery on maximal muscle strength, rapid muscle force [rate of force development (RFD)], muscle activation, and muscle size. Thirty-six subjects (60–86 yr) were randomized to a 12-wk rehabilitation program consisting of either 1) strength training (3 times/wk for 12 wk), 2) electrical muscle stimulation (1 h/day for 12 wk), or 3) standard rehabilitation (1 h/day for 12 wk). The nonoperated side did not receive any intervention and thereby served as a within-subject control. Thirty subjects completed the trial. In the strength-training group, significant increases were observed in maximal isometric muscle strength (24%, P < 0.01), contractile RFD (26–45%, P < 0.05), and contractile impulse (27–32%, P < 0.05). No significant changes were seen in the two other training groups or in the nontrained legs of all three groups. Mean electromyogram signal amplitude of vastus lateralis was larger in the strength-training than in the standard-rehabilitation group at 5 and 12 wk ( P < 0.05). In contrast to traditional physiotherapy and electrical stimulation, strength training increased muscle mass, maximal isometric strength, RFD, and muscle activation in elderly men and women recovering from long-term muscle disuse and subsequent hip surgery. The improvement in both muscle mass and neural function is likely to have important functional implications for elderly individuals.

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