scholarly journals Alterations in peak torque occur without hematological changes after muscle fatigue

2017 ◽  
Vol 23 (3) ◽  
pp. 180-183
Author(s):  
Frank Shiguemitsu Suzuki ◽  
Marcelo Martins Kalytczak ◽  
Rodrigo Augusto Ferreira Palomares ◽  
Marcos Rodolfo Paunksnis ◽  
Sergio Matias Silva ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Hematological Parameters ◽  
Peak Torque ◽  
Knee Extension ◽  
Muscular Fatigue ◽  
Adult Males ◽  
Fatigue Protocol ◽  
Isometric Torque ◽  
Hematological Changes ◽  
Inactive Group

ABSTRACT Introduction: Muscular fatigue during voluntary muscle contractions is a complex and multifactorial phenomenon associated with central changes and adaptations of the neuromuscular system. Objective: The aim of this study was to analyze the changes in both peak torque and hematological parameters in active and inactive healthy subjects following a muscular fatigue protocol. Methods: Twenty-one healthy adult males performed a muscle fatigue protocol (10 sets, 10 repetitions of knee extension at 75% of the maximal isometric torque (MIT), 120º s-1 and 40 seconds of rest). Hematocrit (Ht), red blood cells (RBC) and leukocytes (L) analysis were evaluated before (B) and after (A) a fatigue test. Results: The inactive group presented impairment only in concentric muscular action of -41±4% in relation to the active (-23±3%) group. No differences were found in hematological parameters in inactive group (Ht, B: 45.00±0.01 vs. A: 47.00±0.01; RBC, B: 442±40 vs. A: 487±41; L, B: 7,565±2,878 vs. A: 8,015±4,224) and the active group (Ht, B: 45.00±0.63 vs. A: 47.00±0.01; RBC, B: 477±30 vs. A: 559±37; L, B: 6,418±3,557 vs. A: 6,632±4,460). Conclusion: Differences were found only in concentric actions between groups. Additionally, there were no relationships found in hematological parameters between groups.

scholarly journals The effect of Soft Tissue Manipulation and Rest on Knee Extensor Muscles Fatigue: Do torque Parameters and Induced Perception Following Muscle Fatigue Have Enough Reliability?

2019 ◽  
Author(s):  
Cobra Ghasemi ◽  
Ali Amiri ◽  
Javad Sarrafzadeh ◽  
Hasan Jafari ◽  
Mehdi Dadgoo
Keyword(s):  
Soft Tissue ◽  
Muscle Fatigue ◽  
Visual Analog Scale ◽  
Average Power ◽  
Knee Extensor ◽  
Peak Torque ◽  
Analog Scale ◽  
Fatigue Protocol ◽  
Tissue Manipulation ◽  
The Stability

Abstract Background The aim of the study is comparison of the effects of soft tissue manipulation and rest on the knee extensor muscle fatigue after maximal isokinetic contractions. Methods Fifteen healthy females aged 20-30 years selected for research. This study implemented a semi-experimental test-retest measurement method. Each of the volunteers was evaluated three sessions. The first session was to familiarize the volunteers with the test and isokinetics. For the main test, each of the volunteers was evaluated twice with a one-week interval between evaluations. In each session, after warm-up, perceived fatigue using a visual analog scale (VAS), average of peak torque (APT), and average power (AP) for maximal concentric isokinetic output of the quadriceps was measured at a velocity of 60 degrees per second. Then¸ in order to apply the fatigue protocol, the subjects were asked to perform successive maximal quadriceps contractions until three consecutive quadriceps torque outputs reached below 50 percent maximal torque output. Afterwards, for remeasurement, the average of peak torque and average power were calculated. The extent of perceived fatigue was evaluated as before. Subjects then either rested or received soft tissue manipulation on the knee extensors for a 15-minute duration. After intervention (soft tissue manipulation or rest) parameters were evaluated for third time. Results The stability of average peak torque¸ average power, and visual analog scale before performing fatigue protocol was 85%, 83%, and 31.9%, respectively. The stability after fatigue was 43%, 50%, and 93%, respectively. After maximal fatigue and a decrease in torque output to below 50 percent maximal torque, 15 minutes of soft tissue manipulation could change the APT after fatigue from a mean of 58.3 (nm) to 91.5 (nm), the AP from 39.4 to 63.6 (nm/s), and the VAS from 90.0 to 12 (mm). But 15 minutes of rest could change the APT from 52.5 to 68.1 (nm), the AP from 37.6 to 48 (nm/s) and the VAS from 90.0 to 27.3 (mm). Conclusion The study showed that soft tissue manipulation was more effective than rest as a strategy to return muscles to a normal state and caused more relief in perceived fatigue.

Age- and sex-associated differences in isokinetic knee muscle endurance between young children and adults

2009 ◽  
Vol 34 (4) ◽  
pp. 725-731 ◽  
Author(s):  
Mark B.A. De Ste Croix ◽  
Martine A. Deighan ◽  
Sebastien Ratel ◽  
Neil Armstrong
Keyword(s):  
Young Children ◽  
Peak Torque ◽  
Knee Extension ◽  
Total Work ◽  
Adult Males ◽  
Significant Interaction Effect ◽  
Peak Knee ◽  
Knee Muscle ◽  
Main Effects ◽  
Age And Sex

The purpose of this study was to examine the age- and sex-associated differences of repeated isokinetic knee extension and flexion. Fifty one participants, 30 young children (16 boys and 14 girls; aged 11 and 12 years) and 21 adults (9 males and 12 females; aged 18–35 years), agreed to participate in the study. Isokinetic concentric peak knee extension (PET) and flexion (PFT) torque were measured using a calibrated Biodex System 3. Participants performed 4 concentric extension–flexion cycles with maximum effort; after a 2 min rest, 50 continuous concentric cycles were performed at 1.56 rad·s–1. Total work of the extensors (WKEX) and flexors (WKFL) for the complete 50 repetitions was recorded. Average peak torque and average work for the first and last 3 repetitions were calculated to represent the percentage decline in torque and work. There were no significant differences between groups in the peak torque generated during the pretrial and endurance task, suggesting that participants gave a maximal effort at the start of the endurance task. There was a significant interaction effect in the total work done for both extensors and flexors, with adult males producing the greatest amount of work (6622 and 3444 J, respectively). When total work was divided by body mass, there were no significant sex effects, only main effects for group. The percentage decline for PET (40% vs. 60%), PFT (50% vs. 65%), WKET (43% vs. 61%), and WKFL (60% vs. 69%) demonstrated significant main effects for group, with greater fatigue in adults. We found no significant sex effect for fatigue. This study concludes that females do not resist fatigue from repeated isokinetic muscle actions to a greater extent than males, and that the greater fatigue in adults than in children is probably a product of greater initial torque production and work performed.

Effect of Trunk-Muscle Fatigue and Lactic Acid Accumulation on Balance in Healthy Subjects

2008 ◽  
Vol 17 (4) ◽  
pp. 380-386 ◽  
Author(s):  
Ozgur Surenkok ◽  
Ayse Kin-Isler ◽  
Aydan Aytar ◽  
Zuhal Gültekin
Keyword(s):  
Lactic Acid ◽  
Muscle Fatigue ◽  
Dynamic Balance ◽  
Peak Torque ◽  
Trunk Muscle ◽  
Trunk Flexion ◽  
Fatigue Protocol ◽  
Acid Accumulation ◽  
Dependent Samples ◽  
Flexion And Extension

Objective:This study sought to determine the effects of trunk-muscle fatigue and blood lactic acid elevation on static and dynamic balance.Intervention:Fatigue was induced by an isokinetic protocol, and static and dynamic balance were assessed during bilateral stance using a Kinesthetic Ability Trainer. Subjects participated in a fatigue protocol in which continuous concentric movements at 60°/s were performed until the torque output for both trunk flexion and extension dropped below 25% of the calculated peak torque for 3 consecutive movements.Measures:Before and immediately after the fatigue protocol, blood lactic acid measurements and static- and dynamic-balance measurements were recorded.Results:An increase in lactic acid levels was detected in all subjects. According to a dependent-samples t test, significant differences in balance and lactic acid values were found after the fatigue protocol. There was no correlation between lactic acid accumulation (change between prefatigue and postfatigue levels) and balance-score differences.Conclusion:Trunk-muscle fatigue has an adverse effect on static and dynamic balance.

Skeletal muscle fatigue, strength, and quality in the elderly: the Health ABC Study

2005 ◽  
Vol 99 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Andreas Katsiaras ◽  
Anne B. Newman ◽  
Andrea Kriska ◽  
Jennifer Brach ◽  
Shanthi Krishnaswami ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fatigue ◽  
Knee Flexion ◽  
Peak Torque ◽  
Older Men ◽  
Knee Extension ◽  
Muscle Quality ◽  
Knee Extensors ◽  
Men And Women ◽  
Skeletal Muscle Fatigue

We examined the muscle fatigue characteristics in older men and women and determined whether these were related to the size, strength, or quality of muscle. A total of 1,512 men and women aged 70–79 yr from the Health, Aging, and Body Composition Study participated in this study. Muscle cross-sectional area and attenuation were determined with computed tomography. Skeletal muscle fatigue and strength (peak torque) of the knee extensors and flexors were measured using isokinetic dynamometry. Men were more fatigue resistant than women for both knee extension (fatigue index: 70.4 ± 15.3 vs. 66.9 ± 14.3%; P < 0.05) and knee flexion (67.9 ± 16.4 vs. 64.9 ± 17.6%; P < 0.05). Peak torque and muscle quality (specific torque) were higher in men than women for knee extension (99.6 ± 28.2 vs. 63.0 ± 16.8 N·m and 1.62 ± 0.43 vs. 1.51 ± 0.39 N·m/cm2; both P < 0.05) and for knee flexion (74.0 ± 26.4 vs. 49.6 ± 15.9 N·m and 2.47 ± 1.29 vs. 2.22 ± 0.78 N·m/cm2; both P < 0.05). Total work and power output was greater in men compared with women for both the quadriceps (1,353 ± 451 vs. 832 ± 264 J and 87.7 ± 33.5 vs. 53.3 ± 19.2 W; both P < 0.05) and the hamstrings (741 ± 244 vs. 510 ± 141 J and 35.4 ± 16.0 vs. 23.7 ± 10.2 W; both P < 0.05). In both genders, the quadriceps was able to perform more work with greater power compared with the hamstrings. Those who were stronger actually had greater fatigue after adjusting for age, race, physical activity, and total body fat. In conclusion, older men were more fatigue resistant than women, although in both men and women greater fatigue was not related to muscle weakness.

The Influence of Familiarization Sessions on the Stability of Ramp and Ballistic Isometric Torque in Older Adults

2010 ◽  
Vol 18 (4) ◽  
pp. 390-400 ◽  
Author(s):  
Lilian F. Wallerstein ◽  
Renato Barroso ◽  
Valmor Tricoli ◽  
Marco T. Mello ◽  
Carlos Ugrinowitsch
Keyword(s):  
Older Adults ◽  
Peak Torque ◽  
Knee Extension ◽  
Isometric Knee Extension ◽  
Isometric Torque ◽  
Ballistic Contraction ◽  
The Stability ◽  
Older Men And Women ◽  
Torque Development ◽  
Ramp Contractions

Ramp isometric contractions determine peak torque (PT) and neuromuscular activation (NA), and ballistic contractions can be used to evaluate rate of torque development (RTD) and electrical mechanical delay (EMD). The purposes of this study were to assess the number of sessions required to stabilize ramp and ballistic PT and to compare PT and NA between contractions in older adults. Thirty-five older men and women (age 63.7 ± 3.7 yr, body mass 64.3 ± 10.7 kg, height 159.2 ± 6.6 cm) performed 4 sessions of unilateral ramp and ballistic isometric knee extension, 48 hr apart. PT significantly increased (main time effectp< .05) from the first to the third session, with no further improvements thereafter. There was a trend toward higher PT in ballistic than in ramp contractions. No difference between contraction types on EMG values was observed. Therefore, the authors suggest that 3 familiarization sessions be performed to correctly assess PT. In addition, PT, NA, RTD, and EMD can be assessed with ballistic contraction in older adults.

The Acute Effects of Fast-Paced Walking on Isometric Peak Torque and Rate of Torque Development in Regularly Exercising and Inactive Older Women

2021 ◽  
pp. 1-7
Author(s):  
Ty B. Palmer ◽  
Jarrod Blinch ◽  
Ahalee C. Farrow ◽  
Chinonye C. Agu-Udemba ◽  
Ethan A. Mitchell
Keyword(s):  
Physical Activity ◽  
Older Women ◽  
Peak Torque ◽  
Knee Extension ◽  
Acute Effects ◽  
Rate Of Torque Development ◽  
Isometric Knee Extension ◽  
Before And After ◽  
Inactive Group ◽  
Torque Development

This study aimed to examine the acute effects of fast-paced walking on isometric peak torque and rate of torque development (RTD) in regular exercising and inactive older women. Ten regular exercising (67 ± 4 years) and 10 inactive (68 ± 4 years) older women performed three isometric knee extension contractions before and after a control condition (quiet resting) and an experimental condition of fast-paced walking for 6 min. Peak torque and early (RTD100), late (RTD200), and maximum (peak RTD) RTD measurements were obtained from each contraction. Results showed no significant changes in peak torque, peak RTD, or RTD200 after walking for either group (p > .050). A significant decrease in RTD100 was observed after walking for the inactive group (p = .005) but not for the regular exercisers (p = .909). These findings highlight the importance of physical activity and suggest that a task as simple as walking may impair the rapid strength capacities of inactive older women.

scholarly journals 602 THE EFFECT OF BILATERAL ISOKINETIC KNEE EXTENSION/FLEXION ON JOINT ANGLE AT PEAK TORQUE

1993 ◽  
Vol 25 (Supplement) ◽  
pp. S108 ◽  
Author(s):  
J. R. Bryant ◽  
L. E. Brown ◽  
M. Whitehurst
Keyword(s):  
Joint Angle ◽  
Peak Torque ◽  
Knee Extension

scholarly journals Reliability of a New Portable Dynamometer for Assessing Hip and Lower Limb Strength

2021 ◽  
Vol 11 (8) ◽  
pp. 3391
Author(s):  
Jan Marušič ◽  
Goran Marković ◽  
Nejc Šarabon
Keyword(s):  
Lower Limb ◽  
External Rotation ◽  
Peak Torque ◽  
Knee Extension ◽  
Lower Limb Muscles ◽  
Lower Limb Strength ◽  
Flexion Extension ◽  
Strength Tests ◽  
Hip Abduction ◽  
Maximal Peak

The purpose of this study was to evaluate intra- and inter-session reliability of the new, portable, and externally fixated dynamometer called MuscleBoard® for assessing the strength of hip and lower limb muscles. Hip abduction, adduction, flexion, extension, internal and external rotation, knee extension, ankle plantarflexion, and Nordic hamstring exercise strength were measured in three sessions (three sets of three repetitions for each test) on 24 healthy and recreationally active participants. Average and maximal value of normalized peak torque (Nm/kg) from three repetitions in each set and agonist:antagonist ratios (%) were statistically analyzed; the coefficient of variation and intra-class correlation coefficient (ICC2,k) were calculated to assess absolute and relative reliability, respectively. Overall, the results display high to excellent intra- and inter-session reliability with low to acceptable within-individual variation for average and maximal peak torques in all bilateral strength tests, while the reliability of unilateral strength tests was moderate to good. Our findings indicate that using the MuscleBoard® dynamometer can be a reliable device for assessing and monitoring bilateral and certain unilateral hip and lower limb muscle strength, while some unilateral strength tests require some refinement and more extensive familiarization.

scholarly journals Central excitability does not limit postfatigue voluntary activation of quadriceps femoris

2006 ◽  
Vol 100 (6) ◽  
pp. 1757-1764 ◽  
Author(s):  
J. M. Kalmar ◽  
E. Cafarelli
Keyword(s):  
Evoked Potentials ◽  
Repeated Measures ◽  
Muscle Activation ◽  
Motor Evoked Potentials ◽  
Vastus Lateralis ◽  
Central Fatigue ◽  
Knee Extension ◽  
Voluntary Activation ◽  
Fatigue Protocol ◽  
Central Excitability

After fatigue, motor evoked potentials (MEP) elicited by transcranial magnetic stimulation and cervicomedullary evoked potentials elicited by stimulation of the corticospinal tract are depressed. These reductions in corticomotor excitability and corticospinal transmission are accompanied by voluntary activation failure, but this may not reflect a causal relationship. Our purpose was to determine whether a decline in central excitability contributes to central fatigue. We hypothesized that, if central excitability limits voluntary activation, then a caffeine-induced increase in central excitability should offset voluntary activation failure. In this repeated-measures study, eight men each attended two sessions. Baseline measures of knee extension torque, maximal voluntary activation, peripheral transmission, contractile properties, and central excitability were made before administration of caffeine (6 mg/kg) or placebo. The amplitude of vastus lateralis MEPs elicited during minimal muscle activation provided a measure of central excitability. After a 1-h rest, baseline measures were repeated before, during, and after a fatigue protocol that ended when maximal voluntary torque declined by 35% (Tlim). Increased prefatigue MEP amplitude ( P = 0.055) and cortically evoked twitch ( P < 0.05) in the caffeine trial indicate that the drug increased central excitability. In the caffeine trial, increased MEP amplitude was correlated with time to task failure ( r = 0.74, P < 0.05). Caffeine potentiated the MEP early in the fatigue protocol ( P < 0.05) and offset the 40% decline in placebo MEP ( P < 0.05) at Tlim. However, this was not associated with enhanced maximal voluntary activation during fatigue or recovery, demonstrating that voluntary activation is not limited by central excitability.

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