Fatigue and recovery of power and isometric torque following isotonic knee extensions

2005 ◽  
Vol 99 (4) ◽  
pp. 1446-1452 ◽  
Author(s):  
Arthur J. Cheng ◽  
Charles L. Rice
Keyword(s):  
Relaxation Time ◽  
Voluntary Contraction ◽  
Contractile Properties ◽  
Task Failure ◽  
Motor Unit Activation ◽  
Isometric Torque ◽  
Isotonic Function ◽  
Isotonic Contractions ◽  
Muscle Contractile ◽  
Isometric Muscle

The purpose of this study was to assess fatigue and recovery of isotonic power and isometric contractile properties after a series of maximal isotonic contractions. Using a Biodex dynamometer, 13 men [26 yr (SD 3)] performed isotonic [50% of isometric maximal voluntary contraction (MVC) every 1.2 s through 75° range of motion] single-limb knee extensions at the fastest velocity they could achieve until velocity was reduced by 35%. Time to task failure was 38 s, and, compared with baseline, power declined by ∼42% [741.0 (SD 106.0) vs. 426.5 W (SD 60.3) at task failure], and MVC declined by ∼26% [267.3 (SD 42.5) vs. 198.4 N·m (SD 45.7) at task failure]. Power recovered by 5 min, whereas MVC did not recover, and at 10 min was only ∼85% of baseline. Isometric MVC motor unit activation was ∼95% at rest and was unchanged at task failure (∼96%), but a small amount of failure was apparent between 1.5 and 10 min of recovery (∼87 to ∼91%). Half relaxation time measured from a 50-Hz isometric tetanus was significantly prolonged by ∼33% immediately after task failure but recovered by 1.5 min. A decline in the 10- to 50-Hz ratio of the evoked isometric contractions was observed at 5 and 10 min of recovery, which suggests excitation-contraction coupling impairment. Changes in velocity and half relaxation time during the protocol were strongly and negatively correlated ( r = −0.85). Thus mainly peripheral mechanisms were implicated in the substantial depression but relatively fast recovery of isotonic power. Furthermore, isometric muscle contractile properties were related to some, but not all, changes in isotonic function.

Shortening of muscle relaxation time after creatine loading

1999 ◽  
Vol 86 (3) ◽  
pp. 840-844 ◽  
Author(s):  
M. van Leemputte ◽  
K. Vandenberghe ◽  
P. Hespel
Keyword(s):  
Relaxation Time ◽  
Muscle Relaxation ◽  
Muscle Contractions ◽  
Contraction Time ◽  
Healthy Male ◽  
Healthy Male Volunteers ◽  
Torque Generation ◽  
Isometric Torque ◽  
The Mean ◽  
Isometric Muscle

The effect of creatine (Cr) supplementation on muscle isometric torque generation and relaxation was investigated in healthy male volunteers. Maximal torque (Tmax), contraction time (CT) from 0.25 to 0.75 of Tmax, and relaxation time (RT) from 0.75 to 0.25 of Tmax were measured during 12 maximal isometric 3-s elbow flexions interspersed by 10-s rest intervals. Between the pretest and the posttest, subjects ingested Cr monohydrate (4 × 5 g/day; n = 8) or placebo ( n = 8) for 5 days. Pretest Tmax, CT, and RT were similar in Cr and placebo groups. Also in the posttest, Tmax and CT were similar between groups. However, posttest RT was decreased consistently by ∼20% ( P < 0.05) in the Cr group from the first to the last of the 12 contractions. In addition, the mean decrease in RT after Cr loading was positively correlated with pretest RT ( r = 0.82). It is concluded that Cr loading facilitates the rate of muscle relaxation during brief isometric muscle contractions without affecting torque production.

Effect of caffeine on skeletal muscle function before and after fatigue

1983 ◽  
Vol 54 (5) ◽  
pp. 1303-1305 ◽  
Author(s):  
J. M. Lopes ◽  
M. Aubier ◽  
J. Jardim ◽  
J. V. Aranda ◽  
P. T. Macklem
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Relaxation Rate ◽  
Voluntary Contraction ◽  
Contractile Properties ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Muscle Contractile Properties ◽  
Before And After ◽  
Muscle Contractile

We studied the effect of caffeine on voluntary and electrically stimulated contractions of the adductor pollicis muscle in five adult volunteers. Caffeine (500 mg) was administered orally in a double-blind fashion. Electrical stimulation of the ulnar nerve was performed at 10, 20, 30, 50, and 100 Hz before and after a sustained voluntary contraction held at 50% of the maximal voluntary contraction (MVC). A brief tetanus at 30 Hz was also performed to calculate relaxation rate in the fresh muscle. Contractile properties, relaxation rate, and endurance were then assessed after caffeine and placebo, as well as the response of the fatigued muscle to different frequencies of stimulation. There was no difference in the maximal tension obtained with electrical stimulation (T100) or in the MVC between placebo and caffeine. The tensions developed with electrical stimulation at lower frequencies increased significantly with caffeine ingestion, shifting the frequency-force curve to the left, both before and after fatigue. Mean plasma caffeine concentration associated with these responses was 12.2 +/- 4.9 mg/l. We conclude that caffeine has a direct effect on skeletal muscle contractile properties both before and after fatigue as demonstrated by electrical stimulation.

Muscle contractile properties during intermittent nontetanic stimulation in rat skeletal muscle

2001 ◽  
Vol 281 (6) ◽  
pp. R1952-R1965 ◽  
Author(s):  
Esther Verburg ◽  
Hanne-Mari Schiøtz Thorud ◽  
Morten Eriksen ◽  
Nina K. Vøllestad ◽  
Ole M. Sejersted
Keyword(s):  
Skeletal Muscle ◽  
Relaxation Time ◽  
Low Frequency ◽  
Creatine Phosphate ◽  
Contractile Properties ◽  
Second Phase ◽  
Phase Relaxation ◽  
Two Phase ◽  
Muscle Contractile

To examine changes in contractile properties and mechanisms of fatigue during submaximal nontetanic skeletal muscle activity, in situ perfused soleus (60-min protocol) and extensor digitorum longus (EDL; 10-min protocol) muscles of the rat were electrically stimulated intermittently at low frequency. The partly fused trains of contractions showed a two-phase change in appearance. During the first phase, relaxation slowed, one-half relaxation time increased, and maximal relaxation first derivative of force (dF/d t) decreased. Developed force during the trains was reduced and was closely related to the rate of relaxation in this first phase. During the second phase, relaxation became faster again, one-half relaxation time decreased, and force returned to resting levels between contractions in a train. In contrast, developed force remained reduced, so that peak force of the contractions was 51% (soleus) and 30% (EDL) of control. In the soleus muscle, the changes in contractile properties were not related to ATP, creatine phosphate, or lactate content. The changes in contractile properties fit best with a mechanism of fatigue involving changes in Ca2+ handling by the sarcoplasmic reticulum.

Effects of Kinesio Taping on Muscle Contractile Properties: Assessment Using Tensiomyography

2021 ◽  
pp. 1-8
Author(s):  
Seda Yildiz ◽  
Uluç Pamuk ◽  
Gul Baltaci ◽  
Can A. Yucesoy
Keyword(s):  
Relaxation Time ◽  
Delay Time ◽  
Radial Displacement ◽  
Force Production ◽  
Muscle Stiffness ◽  
Contractile Properties ◽  
Contraction Time ◽  
Kinesio Taping ◽  
Post Hoc ◽  
Muscle Contractile

Context: Although functional effects of kinesio taping (KT) have been widely studied, its effects on contractile properties of the target muscle remain unclear. Tensiomyography is suitable for quantifying muscle stiffness and rate of force development upon imposed twitch contraction. Objective: To test the hypothesis that KT has effects on contractile properties of targeted muscle using tensiomyography. Design: Prospective cohort study. Settings: Performance laboratory of a sports rehabilitation center. Participants: A total of 11 healthy volunteers. Interventions: Tensiomyography measurements before KT facilitation technique applied (pre-KT), 45 minutes, and 24 hours after KT (post-KT1 and post-KT2, respectively) without removing the tape. Main Outcome Measures: Maximal radial displacement, contraction time, delay time, sustain time, relaxation time, and velocity of contraction. Results: Significant effects were shown for maximal radial displacement (P = .004), contraction time (P = .013), relaxation time (P = .035), and velocity of contraction (P = .0033), but not for delay time (P = .060) and sustain time (P = .078). Post hoc testing indicated a significant decrease in maximal radial displacement for post-KT1 only (from 6.33 [1.46] to 4.87 [2.14] mm), and a significant increase in contraction time for both post-KT1 and post-KT2 (from 30.87 [11.39] to 39.71 [13.49] ms, and 37.41 [14.73] ms, respectively). Post hoc testing also showed a significant decrease in relaxation time for post-KT2 (from 65.97 [53.43] to 47.45 [38.12] ms), and a significant decrease in velocity of contraction for both post-KT1 and post-KT2 (from 0.22 [0.08] to 0.15 [0.09] mm/s, and 0.16 [0.07] mm/s), respectively. Conclusion: The findings indicate that KT leads to an increased muscle stiffness and a reduced muscle rate of force production despite the facilitation technique applied.

Isometric torque and shortening velocity following fatigue and recovery of different voluntary tasks in the dorsiflexors

2009 ◽  
Vol 34 (5) ◽  
pp. 866-874 ◽  
Author(s):  
Arthur J. Cheng ◽  
Charles L. Rice
Keyword(s):  
Maximum Rate ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Shortening Velocity ◽  
Related Factors ◽  
Task Failure ◽  
Young Males ◽  
Dynamic Task ◽  
Dynamic Contractions ◽  
Isometric Torque

The present study was designed to compare the relative influence of various fatigue-related factors involved in isometric and dynamic task failure following an equivalent decrease in isometric maximum voluntary contraction (MVC) torque. Using a similar duty cycle (∼1-s contraction per 2 s) and contraction load (50% of MVC), 9 young males performed in the dorsiflexors a dynamic task, and on a separate occasion an intermittent isometric task, to an equal decrease in isometric MVC torque. Dynamic contractions had greater motor unit activation and maximum rate of torque development, and required fewer contractions to task failure than the isometric task, indicating a faster development of fatigue during the velocity-dependent dynamic contractions. Peripheral factors, rather than impairments in voluntary drive, were responsible for the equivalent decrease in MVC torque at task failure and its subsequent incomplete recovery. These included, for both tasks, similar changes during fatigue and recovery in voluntary isometric MVC torque, shortening velocity, stimulated twitch and 50 Hz torque, and 50 Hz maximum rate of relaxation. Irrespective of the task, however, the greater reduction in shortening velocity at task failure and its subsequent faster recovery than MVC torque suggest that changes in metabolites affect velocity to a greater extent than isometric torque.

Effects of selenium supplementation on the muscle contractile properties, fatigue and antioxidant enzymes activities of gastrocnemius muscles in trained and untrained rats

2011 ◽  
Vol 1 (4) ◽  
pp. 226-232
Author(s):  
Mohanad R. Alwan ◽  
Oleksandr Krasilshchikov ◽  
Tengku Muzaffar Bin ◽  
Tengku Mohamad Shihabudin
Keyword(s):  
Lipid Peroxidation ◽  
Selenium Supplementation ◽  
Contractile Properties ◽  
Muscle Contractile Properties ◽  
Body Weights ◽  
Jumping Exercise ◽  
Antioxidant Enzymes Activities ◽  
Gastrocnemius Muscles ◽  
Muscle Contractile ◽  
Tetanic Tension

Selenium (Se) is an important component of cellular seleno Ã¢â‚¬Âcompounds andan integral component of glutathione Peroxidase (GPx), which catalyzes thereduction of harmful radicals produced during muscular exercise. The currentstudy was carried out to evaluate the muscle contractile properties andfatigue resistance of gastrocnemius muscle under selenium supplementationschemes in sedentary and exercise protocols as well as measure the antioxidantenzymes activity and lipid peroxidation. Rats were divided into fourgroups; sedentary Selenium supplementation (S), exercise Selenium (SE)groups, sedentary control (SC) and exercise control (EC) groups. The ratswere fed with 80 μg/kg body weights selenium for six weeks. The exerciseprotocol consisted the 40 jumps up to the height of 40 cm for 6 Ã¢â‚¬Âweek. Themuscle fatigue protocol consisted the trains of pulses of 40 Hz at every secondfor at least 2 min. Significant (P<0.05) increase was observed in treatedgroups than control in the muscle contractile properties like twitch tension(Pt), contraction time (CT) and twitch/tetanic tension Ratio (Pt/Po Ratio),tetanic tension (Po) and EMG amplitude. Decreased EMG failure and increasedfatigue index were observed in ES group. Moreover, a significant(P<0.05) increase and decrease in the GPx activity and lipid peroxidation respectivelywas also reported than SC and EC group. While there were nochanges reported in the activity of CAT and SOD enzymes. This study revealedthat the Se with jumping exercise induces muscle contractile propertiesand decreases the muscular fatigue.

scholarly journals Corticosteroid effects on isotonic contractile properties of rat diaphragm muscle

1997 ◽  
Vol 83 (4) ◽  
pp. 1062-1067 ◽  
Author(s):  
Roland H. H. Van Balkom ◽  
Wen-Zhi Zhan ◽  
Y. S. Prakash ◽  
P. N. Richard Dekhuijzen ◽  
Gary C. Sieck
Keyword(s):  
Isometric Force ◽  
Contractile Properties ◽  
Diaphragm Muscle ◽  
Peak Power Output ◽  
Rat Diaphragm ◽  
Fiber Morphology ◽  
Shortening Velocity ◽  
Maximum Isometric Force ◽  
Induced Changes ◽  
Isotonic Contractions

Van Balkom, Roland H. H., Wen-Zhi Zhan, Y. S. Prakash, P. N. Richard Dekhuijzen, and Gary C. Sieck. Corticosteroid effects on isotonic contractile properties of rat diaphragm muscle. J. Appl. Physiol. 83(4): 1062–1067, 1997.—The effects of corticosteroids (CS) on diaphragm muscle (Diam) fiber morphology and contractile properties were evaluated in three groups of rats: controls (Ctl), surgical sham and weight-matched controls (Sham), and CS-treated (6 mg ⋅ kg−1 ⋅ day−1prednisolone at 2.5 ml/h for 3 wk). In the CS-treated Diam, there was a selective atrophy of type IIx and IIb fibers, compared with a generalized atrophy of all fibers in the Sham group. Maximum isometric force was reduced by 20% in the CS group compared with both Ctl and Sham. Maximum shortening velocity in the CS Diamwas slowed by ∼20% compared with Ctl and Sham. Peak power output of the CS Diam was only 60% of Ctl and 70% of Sham. Endurance to repeated isotonic contractions improved in the CS-treated Diam compared with Ctl. We conclude that the atrophy of type IIx and IIb fibers in the Diam can only partially account for the CS-induced changes in isotonic contractile properties. Other factors such as reduced myofibrillar density or altered cross-bridge cycling kinetics are also likely to contribute to the effects of CS treatment.

Contractile properties of expiratory abdominal muscles: effect of elastase-induced emphysema

1987 ◽  
Vol 62 (6) ◽  
pp. 2314-2319 ◽  
Author(s):  
J. S. Arnold ◽  
A. J. Thomas ◽  
S. G. Kelsen
Keyword(s):  
Relaxation Time ◽  
Contractile Function ◽  
Isometric Tension ◽  
Contractile Properties ◽  
Abdominal Muscles ◽  
Force Frequency ◽  
Contraction Time ◽  
Transverse Abdominis ◽  
External Oblique

The present study examined the intrinsic contractile properties and endurance of the transverse abdominis and external oblique abdominal expiratory muscles in adult hamsters and compared their performance with the diaphragm. Experiments were performed in vitro on isolated bundles of muscle stimulated electrically. In control animals peak twitch tension was similar in the two muscles. In contrast, the twitch contraction time and one-half relaxation time of the transverse abdominis were significantly greater than that of the external oblique. The isometric tension generated over a range of stimulus frequencies (i.e., the force-frequency relationship) was a greater percent of the maximum value in response to subtetanizing frequencies (10–40 Hz) in the transverse abdominis than in the external oblique. For both abdominal muscles, however, the tension generated over this range of stimulus frequencies was less than that of the diaphragm. The endurance of the transverse abdominis during repeated contractions was significantly greater than that of the external oblique but similar to the diaphragm. The effect of chronic hyperinflation produced by elastase-induced emphysema on the contractile function of the two muscles was assessed in a second group of adult hamsters. In emphysematous animals peak twitch tension, contraction time, and one-half relaxation time of the twitch and force-frequency curves of muscles from emphysematous animals were similar to values obtained in control animals for both the external oblique and transverse abdominis. However, the endurance of both the transverse abdominis and external oblique muscles was greater in emphysematous than control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

The Influence of Intermittent Fatigue Exercise on Early and Late Phases of Relaxation From Maximal Voluntary Contraction

1997 ◽  
Vol 22 (6) ◽  
pp. 573-584 ◽  
Author(s):  
Anna Jaskólska ◽  
Artur Jaskólski
Keyword(s):  
Relaxation Time ◽  
Relaxation Rate ◽  
Maximal Voluntary Contraction ◽  
Early Phase ◽  
Intermittent Exercise ◽  
Young Male ◽  
Voluntary Contraction ◽  
Hand Grip ◽  
Before And After ◽  
Late Relaxation Time

Twenty-two young male subjects were tested to estimate the behavior of the early and late phases of relaxation from a 3-s maximal voluntary contraction (MVC) under the influence of fatigue. Less demanding and more demanding protocols of intermittent hand grip exercise were used to fatigue muscle. Before and after fatigue, the early and late relaxation time, maximal relaxation rate, and half-relaxation time were measured. The results showed that during voluntary movement (a) the early phase of relaxation was independent of the mode of intermittent exercise and did not change significantly after fatigue; (b) the late relaxation time and absolute maximal relaxation rate were slower after both protocols, with the changes more pronounced following the more demanding protocol; and (c) the half-relaxation time and relative maximal relaxation rate were changed only in the more demanding protocol. It is concluded that unlike the relaxation following electrical stimulation of isolated muscle, the early phase of relaxation from voluntary contraction appears to be the most resistant to the type of intermittent fatiguing exercise used in the present study, whereas the late relaxation time was the most sensitive to this type of fatigue. Key words: hand grip exercise, late relaxation time, early relaxation time, half-relaxation time

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