Age- and Sex-Related Differences in the Maximum Muscle Performance and Rate of Force Development Scaling Factor of Precision Grip Muscles

Motor Control ◽  
2020 ◽  
Vol 24 (2) ◽  
pp. 274-290
Author(s):  
Talyene G.C. Corrêa ◽  
Stephanie V.S. Donato ◽  
Kauê C.A. Lima ◽  
Ronaldo V. Pereira ◽  
Mehmet Uygur ◽  
...  
Keyword(s):  
Grip Force ◽  
Isometric Force ◽  
Maximum Voluntary Contraction ◽  
Precision Grip ◽  
Voluntary Contraction ◽  
Scaling Factor ◽  
Rate Of Force Development ◽  
Muscle Performance ◽  
Force Development ◽  
Age And Sex

The aim of this study was to explore the effects of age and sex on the rate of force development scaling factor (RFD-SF) and maximum performance (i.e., maximum grip force [GFMax] and maximum rate of grip force development [RGFDMax]) of precision handgrip muscles. Sixty-four subjects, allocated in four groups according to their age and sex, were asked to hold an instrumented handle with the tip of the digits and perform two tests: maximum voluntary contraction and RFD-SF tests. In the maximum voluntary contraction test, GFMax and RGFDMax were assessed. In the RFD-SF test, the subjects generated quick isometric force pulses to target amplitudes varying between 20% and 100% of their GFMax. The RFD-SF and R2 values were obtained from the linear relationship between the peak values of the force pulses and the corresponding peak values of the rate of force development. Younger adults and males produced higher GFMax and RGFDMax and presented higher R2 and RFD-SF than older adults and females, respectively. No correlations between GFMax and RFD-SF and between RGFDMax and RFD-SF were observed.

scholarly journals Advancements in the Protocol for Rate of Force Development/Relaxation Scaling Factor Evaluation

2021 ◽  
Vol 15 ◽  
Author(s):  
Darjan Smajla ◽  
Jure Žitnik ◽  
Nejc Šarabon
Keyword(s):  
Outcome Measure ◽  
Isometric Force ◽  
Cross Sectional Study ◽  
Scaling Factor ◽  
Rate Of Force Development ◽  
Knee Extensors ◽  
Cross Sectional ◽  
Force Development ◽  
Wide Range ◽  
Neuromuscular Assessment

Brief submaximal actions are important for wide range of functional movements. Until now, rate of force development and relaxation scaling factor (RFD-SF and RFR-SF) have been used for neuromuscular assessment using 100–120 isometric pulses which requires a high level of attention from the participant and may be influenced by physiological and/or psychological fatigue. All previous studies have been conducted on a smaller number of participants which calls into question the eligibility of some of the outcome measures reported to date. Our aims were: (1) to find the smallest number of rapid isometric force pulses at different force amplitudes is still valid and reliable for RFD-SF slope (kRFD–SF) and RFR-SF slope (kRFR–SF) calculation, (2) to introduce a new outcome measure – theoretical peak of rate of force development/relaxation (TPRFD and TPRFR) and (3) to investigate differences and associations between kRFD–SF and kRFR–SF. A cross-sectional study was conducted on a group of young healthy participants; 40 in the reliability study and 336 in the comparison/association study. We investigated the smallest number of rapid isometric pulses for knee extensors that still provides excellent reliability of the calculated kRFD–SF and kRFR–SF (ICC2,1 ≥ 0.95, CV < 5%). Our results showed excellent reliability of the reduced protocol when 36 pulses (nine for each of the four intensity ranges) were used for the calculations of kRFD–SF and kRFR–SF. We confirmed the negligibility of the y-intercepts and confirmed the reliability of the newly introduced TPRFD and TPRFR. Large negative associations were found between kRFD–SF and kRFR–SF (r = 0.502, p < 0.001), while comparison of the absolute values showed a significantly higher kRFD–SF (8.86 ± 1.0/s) compared to kRFR–SF (8.03 ± 1.3/s) (p < 0.001). The advantage of the reduced protocol (4 intensities × 9 pulses = 36 pulses) is the shorter assessment time and the reduction of possible influence of fatigue. In addition, the introduction of TPRFD and TPRFR as an outcome measure provides valuable information about the participant’s maximal theoretical RFD/RFR capacity. This can be useful for the assessment of maximal capacity in people with various impairments or pain problems.

Isometric rate of force development, maximum voluntary contraction, and balance in women with and without joint hypermobility

2008 ◽  
Vol 59 (11) ◽  
pp. 1665-1669 ◽  
Author(s):  
Christine Mebes ◽  
Astrid Amstutz ◽  
Gere Luder ◽  
Hans-Ruedi Ziswiler ◽  
Matthias Stettler ◽  
...  
Keyword(s):  
Maximum Voluntary Contraction ◽  
Joint Hypermobility ◽  
Voluntary Contraction ◽  
Rate Of Force Development ◽  
Force Development

Acute Physiological Response to Light- and Heavy-load Power-oriented Exercise in Older Adults

2021 ◽  
Author(s):  
Carlos Rodriguez-Lopez ◽  
Julian Alcazar ◽  
Jose Losa-Reyna ◽  
JuanManuel Carmona-Torres ◽  
Aurora Maria Cruz-Santaella ◽  
...  
Keyword(s):  
Older Adults ◽  
Creatine Kinase ◽  
Resistance Training ◽  
Isometric Force ◽  
Rate Of Force Development ◽  
Heavy Load ◽  
Force Development ◽  
Sit To Stand ◽  
Light Load ◽  
Maximal Isometric Force

AbstractThis study investigated the acute responses to volume-load-matched heavy-load (80% 1RM) versus light-load (40% 1RM) power-oriented resistance training sessions in well-functioning older adults. Using a randomized cross-over design, 15 volunteers completed each condition on a leg press. Neuromuscular (maximal isometric force and rate of force development) and functional performance (power during sit-to-stand test), lactate, and muscle damage biochemistry (creatine kinase, lactate dehydrogenase and C-reactive protein serum concentration) were assessed pre- and post-exercise. Performance declines were found after heavy-load (Cohen’s d effect size (d); maximal isometric force=0.95 d; rate of force development=1.17 d; sit-to-stand power =0.38 d, all p<0.05) and light-load (maximal isometric force=0.45 d; rate of force development=0.9 d; sit-to-stand power=1.17 d, all p<0.05), while lactate concentration increased only after light-load (1.7 d, p=0.001). However, no differences were found between conditions (all p>0.05). Both conditions increased creatine kinase the day after exercise (marginal effect=0.75 d, p<0.001), but no other blood markers increased (all, p>0.05). Irrespective of the load used, power training induced non-clinically significant decreases in sit-to-stand performance, moderate declines in maximal isometric force, but pronounced decreases in the rate of force development. Furthermore, the metabolic stress and muscle damage were minor; both sessions were generally well tolerated by well-functioning older adults without previous experience in resistance training.

Relationship Between Isometric Force–Time Characteristics and Sprint Kayaking Performance

2020 ◽  
pp. 1-6
Author(s):  
Danny Lum ◽  
Abdul Rashid Aziz
Keyword(s):  
Bench Press ◽  
Isometric Force ◽  
Rate Of Force Development ◽  
Isometric Strength ◽  
Mean Power ◽  
Force Development ◽  
Peak Rate ◽  
Time To Completion ◽  
Strength Tests ◽  
Force Time

Force–time characteristics obtained during isometric strength tests are significantly correlated to various sporting movements. However, data on the relationship between isometric force–time characteristics and sprint kayaking performance are lacking in the literature. Purpose: The purpose of the study was, therefore, to investigate the relationship between sprint kayaking performance with ergometer performance and measures from 3 isometric strength tests: isometric squat, isometric bench press, and isometric prone bench pull. Methods: A total of 23 sprint kayaking athletes performed all 3 tests, at 90° and 120° knee angles for isometric squat and at elbow angles for isometric bench press and isometric prone bench pull, and a 200-m sprint on-water to attain the fastest time-to-completion (OWTT) possible and on a kayak ergometer to attain the highest mean power (LABTT) possible. Results: There was a significant inverse correlation between OWTT and LABTT (r = −.90, P < .001). The peak forces achieved from all isometric strength tests were significantly correlated with time-to-completion for OWTT and mean power for LABTT (r = −.44 to −.88, P < .05 and .47 to .80, P < .05, respectively). OWTT was significantly correlated with the peak rate of force development during all isometric tests except for the isometric squat at a 120° knee angle (r = −.47 to −.62, P < .05). LABTT was significantly correlated with peak rate of force development from the isometric bench press and isometric prone bench pull (r = .64–.86, P < .01). Conclusion: Based on the observed strong correlations, the mean power attained during LABTT is a good predictor of OWTT time-to-completion. Furthermore, upper- and lower-body maximum strength and peak rate of force development are equally important for on-water and ergometer sprint kayaking performance.

Muscle fiber composition, jumping performance, and rate of force development adaptations induced by different power training volumes in females

2020 ◽  
Vol 45 (9) ◽  
pp. 996-1006 ◽  
Author(s):  
Spyridon Methenitis ◽  
Thomas Mpampoulis ◽  
Polyxeni Spiliopoulou ◽  
George Papadimas ◽  
Constantinos Papadopoulos ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Isometric Force ◽  
Fiber Type ◽  
High Volume ◽  
Rate Of Force Development ◽  
Training Volume ◽  
Power Training ◽  
Power Performance ◽  
Force Development ◽  
Low Volume

This study aimed to investigate the effect of 3 different eccentric-only power training volumes on muscle fiber type composition and power performance. Twenty-nine females were assigned into 3 groups and performed 10 weeks of either 3 (low volume), 6 (moderate volume), or 9 (high volume) sets/session of 4 fast-velocity eccentric-only half-squats against 70% of concentric 1-repetition maximum (1RM), followed by 3 maximum countermovement jumps (CMJs) after each set. Half-squat 1RM, CMJ height/power, maximum isometric force, rate of force development (RFD) and muscle fiber cross-sectional area (CSA) were increased in all groups (p = 0.001). Low-volume training induced higher increases in CMJ height/power and early RFD, compared with the moderate- and high-volume training programs (p < 0.001). Significant reductions in type IIx muscle fiber percentages and %CSAs were found after moderate- and high-volume training, with concomitant increases in type IIa fibers (p = 0.001). Significant correlations were found between the changes in type IIa and type IIx percentages, fiber CSA, %CSA, and the changes in performance (r: –0.787 to 0.792; p < 0.05). These results suggest that relatively large eccentric power training volumes may result in detrimental neuromuscular adaptations, minimal changes in early RFD, and a reduction of type IIx muscle fiber percentage. Novelty Low but not high volume of power training maintains type IIx muscle fibers. Early rate of force development increases after a low- or moderate-power training volume, but not after a high-power training volume. Training-induced changes in type IIx muscle fiber percentage is related with changes in early rate of force development.

scholarly journals Intramuscular fiber conduction velocity, isometric force and explosive performance

2016 ◽  
Vol 51 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Spyridon Methenitis ◽  
Gerasimos Terzis ◽  
Nikolaos Zaras ◽  
Angeliki-Nikoletta Stasinaki ◽  
Nikolaos Karandreas
Keyword(s):  
Conduction Velocity ◽  
Muscle Fiber ◽  
Isometric Force ◽  
Vastus Lateralis ◽  
Rate Of Force Development ◽  
Muscle Fiber Conduction Velocity ◽  
Force Development ◽  
Leg Press ◽  
Explosive Performance ◽  
Maximum Isometric Force

Abstract Conduction of electrical signals along the surface of muscle fibers is acknowledged as an essential neuromuscular component which is linked with muscle force production. However, it remains unclear whether muscle fiber conduction velocity (MFCV) is also linked with explosive performance. The aim of the present study was to investigate the relationship between vastus lateralis MFCV and countermovement jumping performance, the rate of force development and maximum isometric force. Fifteen moderately-trained young females performed countermovement jumps as well as an isometric leg press test in order to determine the rate of force development and maximum isometric force. Vastus lateralis MFCV was measured with intramuscular microelectrodes at rest on a different occasion. Maximum MFCV was significantly correlated with maximum isometric force (r = 0.66, p < 0.01), nevertheless even closer with the leg press rate of force development at 100 ms, 150 ms, 200 ms, and 250 ms (r = 0.85, r = 0.89, r = 0.91, r = 0.92, respectively, p < 0.01). Similarly, mean MFCV and type II MFCV were better correlated with the rate of force development than with maximum isometric leg press force. Lower, but significant correlations were found between mean MFCV and countermovement jump power (r = 0.65, p < 0.01). These data suggest that muscle fiber conduction velocity is better linked with the rate of force development than with isometric force, perhaps because conduction velocity is higher in the larger and fastest muscle fibers which are recognized to contribute to explosive actions.

The rate of force development scaling factor (RFD-SF): protocol, reliability, and muscle comparisons

2011 ◽  
Vol 212 (3) ◽  
pp. 359-369 ◽  
Author(s):  
Maria Bellumori ◽  
Slobodan Jaric ◽  
Christopher A. Knight
Keyword(s):  
Scaling Factor ◽  
Rate Of Force Development ◽  
Force Development
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