Plantar flexor muscles of kangaroo rats (D. deserti) shorten at a velocity to produce optimal power during jumping

2021 ◽  
Author(s):  
M. Janneke Schwaner ◽  
David C. Lin ◽  
Craig P. McGowan
Keyword(s):  
Angular Velocity ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Extensor Muscle ◽  
Joint Work ◽  
Shortening Velocity ◽  
Kangaroo Rats ◽  
Optimal Velocity ◽  
Muscle Shortening

During jumping by kangaroo rats, the musculotendon work contributions across all joints are not well understood. Namely, measures of external joint work do not provide information on the contributions from individual muscles or in-series elastic structures. In this study, we examined the functional roles of a major ankle extensor muscle, lateral gastrocnemius (LG), and of a major knee extensor muscle, vastus lateralis (VL), through in vivo sonomicrometry and electromyography techniques, during vertical jumping by kangaroo rats. Our data showed that both muscles increased shortening and activity with higher jumps. We found that knee angular velocity and VL muscle shortening velocity were coupled in time. In contrast, the ankle angular velocity and LG muscle shortening velocity were decoupled, and rapid joint extension near the end of the jump produced high power outputs at the ankle joint. Further, the decoupling of muscle and joint kinematics allowed the LG muscle to prolong the period of shortening velocity near optimal velocity (Vopt), which likely enabled the muscle to sustain maximal power generation. These observations were consistent with a LG tendon that is much more compliant than that of the VL.

In vivo estimation of contraction velocity of human vastus lateralis muscle during “isokinetic” action

2000 ◽  
Vol 88 (3) ◽  
pp. 851-856 ◽  
Author(s):  
Y. Ichinose ◽  
Y. Kawakami ◽  
M. Ito ◽  
H. Kanehisa ◽  
T. Fukunaga
Keyword(s):  
Angular Velocity ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Vastus Lateralis Muscle ◽  
Shortening Velocity ◽  
Full Extension ◽  
Fascicle Length ◽  
Lateralis Muscle ◽  
Angular Velocities

To determine the shortening velocities of fascicles of the vastus lateralis muscle (VL) during isokinetic knee extension, six male subjects were requested to extend the knee with maximal effort at angular velocities of 30 and 150°/s. By using an ultrasonic apparatus, longitudinal images of the VL were produced every 30 ms during knee extension, and the fascicle length and angle of pennation were obtained from these images. The shortening fascicle length with extension of the knee (from 98 to 13° of knee angle; full extension = 0°) was greater (43 mm) at 30°/s than at 150°/s (35 mm). Even when the angular velocity remained constant during the isokinetic range of motion, the fascicle velocity was found to change from 39 to 77 mm/s at 150°/s and from 6 to 19 mm/s at 30°/s. The force exerted by a fascicle changed with the length of the fascicle at changing angular velocities. The peak values of fascicle force and velocity were observed at ∼90 mm of fascicle length. In conclusion, even if the angular velocity of knee extension is kept constant, the shortening velocity of a fascicle is dependent on the force applied to the muscle-tendon complex, and the phenomenon is considered to be caused mainly by the elongation of the elastic element (tendinous tissue).

scholarly journals In vivo strain of the medial vs. lateral quadriceps tendon in patellofemoral pain syndrome

2009 ◽  
Vol 107 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Nicole A. Wilson ◽  
Joel M. Press ◽  
Li-Qun Zhang
Keyword(s):  
Vastus Lateralis ◽  
Knee Extensor ◽  
Pain Syndrome ◽  
Quadriceps Tendon ◽  
Biomechanical Properties ◽  
Patellofemoral Pain ◽  
Control Subjects ◽  
Patellar Maltracking ◽  
Tendon Strain

Patellofemoral pain (PFP) is thought to be related to patellar maltracking due to imbalances in the knee extensor. However, no study has evaluated the in vivo biomechanical properties of the quadriceps tendon in PFP syndrome. Our purpose was to compare the biomechanical properties of the quadriceps tendons in vivo and noninvasively in patients with PFP syndrome to those of control subjects. The null hypothesis was that the quadriceps tendons of PFP subjects would have significantly decreased strain compared with control subjects. Fourteen subjects (7 control, 7 PFP) performed voluntary ramp isometric contractions to a range of torque levels, while quadriceps tendon elongation was measured using ultrasonography. Tendon strain was calculated for the vastus medialis obliquus (VMO) and vastus lateralis (VL) portion of the quadriceps tendon and compared between subjects (control vs. PFP) and within subjects (VMO vs. VL). PFP subjects showed significantly less VMO tendon strain than control subjects ( P < 0.001), but there was no difference in VL tendon strain between PFP and control subjects ( P = 0.100). Relative weakness of the VMO is the most likely cause of the decreased tendon strain seen in subjects with PFP. VMO weakness not only explains the decreased medial tendon strain but also explains the presence of increased lateral patellar translation and lateral patellar spin (distal pole rotates laterally) reported in the literature in this population. This technique can potentially be used in a clinical setting to evaluate quadriceps tendon properties and infer the presence of muscle weakness in PFP.

Calpain-3 is autolyzed and hence activated in human skeletal muscle 24 h following a single bout of eccentric exercise

2007 ◽  
Vol 103 (3) ◽  
pp. 926-931 ◽  
Author(s):  
Robyn M. Murphy ◽  
Craig A. Goodman ◽  
Michael J. McKenna ◽  
Jason Bennie ◽  
Murray Leikis ◽  
...  
Keyword(s):  
Eccentric Exercise ◽  
Human Subjects ◽  
Vastus Lateralis ◽  
Venous Blood ◽  
Knee Extensor ◽  
Vastus Lateralis Muscle ◽  
Healthy Human ◽  
Calpain 3 ◽  
Torque Measurements

The function and normal regulation of calpain-3, a muscle-specific Ca2+-dependent protease, is uncertain, although its absence leads to limb-girdle muscular dystrophy type 2A. This study examined the effect of eccentric exercise on calpain-3 autolytic activation, because such exercise is known to damage sarcomeric structures and to trigger adaptive changes that help prevent such damage on subsequent exercise. Six healthy human subjects performed a 30-min bout of one-legged, eccentric, knee extensor exercise. Torque measurements, vastus lateralis muscle biopsies, and venous blood samples were taken before and up to 7 days following the exercise. Peak isometric muscle torque was depressed immediately and at 3 h postexercise and recovered by 24 h, and serum creatine kinase concentration peaked at 24 h postexercise. The amount of autolyzed calpain-3 was unchanged immediately and 3 h after exercise, but increased markedly (from ∼16% to ∼35% of total) 24 h after the exercise, and returned to preexercise levels within 7 days. In contrast, the eccentric exercise produced little autolytic activation of the ubiquitous Ca2+-activated protease, μ-calpain. Eccentric exercise is the first physiological circumstance shown to result in calpain-3 activation in vivo.

scholarly journals Effects Of Old Age And Contraction Mode On Knee Extensor Muscle Metabolic Economy In Vivo

2020 ◽  
Vol 52 (7S) ◽  
pp. 346-346
Author(s):  
Liam F. Fitzgerald ◽  
Miles F. Bartlett ◽  
R. Anthony Martin ◽  
Ericber Jimenez Francisco ◽  
Frank C. Sup ◽  
...  
Keyword(s):  
Old Age ◽  
Knee Extensor ◽  
Extensor Muscle

In vivo maximal fascicle-shortening velocity during plantar flexion in humans

2015 ◽  
Vol 119 (11) ◽  
pp. 1262-1271 ◽  
Author(s):  
Hugo Hauraix ◽  
Antoine Nordez ◽  
Gaël Guilhem ◽  
Giuseppe Rabita ◽  
Sylvain Dorel
Keyword(s):  
Angular Velocity ◽  
Fiber Type ◽  
Plantar Flexion ◽  
Load Condition ◽  
Ultrasound Images ◽  
Maximal Velocity ◽  
Shortening Velocity ◽  
Hill Model ◽  
Angular Velocities

Interindividual variability in performance of fast movements is commonly explained by a difference in maximal muscle-shortening velocity due to differences in the proportion of fast-twitch fibers. To provide a better understanding of the capacity to generate fast motion, this study aimed to 1) measure for the first time in vivo the maximal fascicle-shortening velocity of human muscle; 2) evaluate the relationship between angular velocity and fascicle-shortening velocity from low to maximal angular velocities; and 3) investigate the influence of musculo-articular features (moment arm, tendinous tissues stiffness, and muscle architecture) on maximal angular velocity. Ultrafast ultrasound images of the gastrocnemius medialis were obtained from 31 participants during maximal isokinetic and light-loaded plantar flexions. A strong linear relationship between fascicle-shortening velocity and angular velocity was reported for all subjects (mean R2 = 0.97). The maximal shortening velocity (VFmax) obtained during the no-load condition (NLc) ranged between 18.8 and 43.3 cm/s. VFmax values were very close to those of the maximal shortening velocity (Vmax), which was extrapolated from the F-V curve (the Hill model). Angular velocity reached during the NLc was significantly correlated with this VFmax ( r = 0.57; P < 0.001). This finding was in agreement with assumptions about the role of muscle fiber type, whereas interindividual comparisons clearly support the fact that other parameters may also contribute to performance during fast movements. Nevertheless, none of the biomechanical features considered in the present study were found to be directly related to the highest angular velocity, highlighting the complexity of the upstream mechanics that lead to maximal-velocity muscle contraction.

Estimate of muscle-shortening rate during locomotion

1985 ◽  
Vol 249 (6) ◽  
pp. R699-R703 ◽  
Author(s):  
S. L. Lindstedt ◽  
H. Hoppeler ◽  
K. M. Bard ◽  
H. A. Thronson
Keyword(s):  
Skeletal Muscle ◽  
Energy Demand ◽  
Muscle Tension ◽  
Knee Extensors ◽  
Shortening Velocity ◽  
Cross Sectional ◽  
Tension Development ◽  
Muscle Shortening ◽  
Shortening Rate

All skeletal muscle can produce roughly the same maximal cross-sectional force; however, the power (energy X time-1) required to develop and maintain that force increases with increasing contraction velocity. Thus the rate of muscle tension development may be of primary importance in setting the energy demand of contracting muscle. We have estimated the rate of muscle shortening during terrestrial locomotion in mammals as a function of body mass. The rate of muscle shortening of the knee extensors is much faster in small than large mammals, scaling in proportion to the -0.23 power of mass. This exponent suggests a constant body size-independent relation among skeletal muscle: O2 consumption, mitochondria content, myosin ATPase activity, and in vivo shortening velocity.

Aerobic exercise does not compromise muscle hypertrophy response to short-term resistance training

2013 ◽  
Vol 114 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Rodrigo Fernandez-Gonzalo ◽  
Thomas Gustafsson ◽  
Per A. Tesch
Keyword(s):  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Muscle Size ◽  
Mrna Levels ◽  
Cross Sectional ◽  
Before And After

This study tested the hypothesis that chronic aerobic and resistance exercise (AE+RE) would elicit greater muscle hypertrophy than resistance exercise only (RE). Ten men (25 ± 4 yr) performed 5 wk unilateral knee extensor AE+RE. The opposing limb was subjected to RE. AE completed 6 hr prior to RE consisted of ∼45 min one-legged cycle ergometry. RE comprised 4 × 7 maximal concentric-eccentric knee extensions. Various indexes of in vivo knee extensor function were measured before and after training. Magnetic resonance imaging (MRI) assessed m. quadricep femoris (QF) cross-sectional area (CSA), volume, and signal intensity (SI). Biopsies obtained from m. vastus lateralis determined fiber CSA, enzyme levels, and gene expression of myostatin, atrogin-1, MuRF-1, PGC-1α, and VEGF. Increases ( P < 0.05) in isometric strength and peak power, respectively, were comparable in AE+RE (9 and 29%) and RE (11 and 24%). AE+RE showed greater increase (14%; P < 0.05) in QF volume than RE (8%). Muscle fiber CSA increased 17% after AE+RE ( P < 0.05) and 9% after RE ( P > 0.05). QF SI increased (12%; P < 0.05) after AE+RE, but not RE. Neither AE+RE nor RE showed altered mRNA levels. Citrate synthase activity increased ( P < 0.05) after AE+RE. The results suggest that the increased aerobic capacity shown with AE+RE was accompanied by a more robust increase in muscle size compared with RE. Although this response was not carried over to greater improvement in muscle function, it remains that intense AE can be executed prior to RE without compromising performance outcome.

scholarly journals In vivo Measurement of Knee Extensor Muscle Function in Mice

10.3791/62211 ◽  
2021 ◽  
Author(s):  
Camille R. Brightwell ◽  
Ted G. Graber ◽  
Benjamin D. Brightwell ◽  
Matthew Borkowski ◽  
Brian Noehren ◽  
...  
Keyword(s):  
Muscle Function ◽  
Knee Extensor ◽  
Extensor Muscle ◽  
In Vivo Measurement

scholarly journals Diurnal Differences in Human Muscle Isometric Force In Vivo Are Associated with Differential Phosphorylation of Sarcomeric M-Band Proteins

Proteomes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 22 ◽  
Author(s):  
Zulezwan Ab Malik ◽  
Kelly A. Bowden Davies ◽  
Elliott C. R. Hall ◽  
Jennifer Barrett ◽  
Samuel A. Pullinger ◽  
...  
Keyword(s):  
Isometric Force ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Human Muscle ◽  
Force Transmission ◽  
Force Output ◽  
Muscle Creatine Kinase ◽  
Maximal Voluntary Isometric Contraction ◽  
C Terminus

We investigated whether diurnal differences in muscle force output are associated with the post-translational state of muscle proteins. Ten physically active men (mean ± SD; age 26.7 ± 3.7 y) performed experimental sessions in the morning (08:00 h) and evening (17:00 h), which were counterbalanced in order of administration and separated by at least 72 h. Knee extensor maximal voluntary isometric contraction (MVIC) force and peak rate of force development (RFD) were measured, and samples of vastus lateralis were collected immediately after exercise. MVIC force was greater in the evening (mean difference of 67 N, 10.2%; p < 0.05). Two-dimensional (2D) gel analysis encompassed 122 proteoforms and discovered 6 significant (p < 0.05; false discovery rate [FDR] = 10%) diurnal differences. Phosphopeptide analysis identified 1693 phosphopeptides and detected 140 phosphopeptides from 104 proteins that were more (p < 0.05, FDR = 22%) phosphorylated in the morning. Myomesin 2, muscle creatine kinase, and the C-terminus of titin exhibited the most robust (FDR < 10%) diurnal differences. Exercise in the morning, compared to the evening, coincided with a greater phosphorylation of M-band-associated proteins in human muscle. These protein modifications may alter the M-band structure and disrupt force transmission, thus potentially explaining the lower force output in the morning.

Effects of Old age and contraction mode on knee extensor muscle ATP flux and metabolic economy in vivo

2021 ◽  
Author(s):  
Liam F. Fitzgerald ◽  
Miles F. Bartlett ◽  
Rajakumar Nagarajan ◽  
Ericber Jimenez Francisco ◽  
Frank C. Sup IV ◽  
...  
Keyword(s):  
Old Age ◽  
Knee Extensor ◽  
Extensor Muscle
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