Muscle function during jumping in frogs. I. Sarcomere length change, EMG pattern, and jumping performance

1996 ◽  
Vol 271 (2) ◽  
pp. C563-C570 ◽  
Author(s):  
G. J. Lutz ◽  
L. C. Rome
Keyword(s):  
Mechanical Properties ◽  
Muscle Function ◽  
Length Change ◽  
Operating Conditions ◽  
Mechanical Power ◽  
Shortening Velocity ◽  
Jumping Performance ◽  
Angular Velocities ◽  
High Level

We determined the influence of temperature on muscle function during jumping to better understand how the frog muscular system is designed to generate a high level of mechanical power. Maximal jumping performance and the in vivo operating conditions of the semimembranosus muscle (SM), a hip extensor, were measured and related to the mechanical properties of the isolated SM in the accompanying paper [Muscle function during jumping in frogs. II. Mechanical properties of muscle: implication for system design. Am. J. Physiol. 271 (Cell Physiol. 40): C571-C578, 1996]. Reducing temperature from 25 to 15 degrees C caused a 1.75-fold decline in peak mechanical power generation and a proportional decline in aerial jump distance. The hip and knee joint excursions were nearly the same at both temperatures. Accordingly, sarcomeres shortened over the same range (2.4 to 1.9 microns) at both temperatures, corresponding to myofilament overlap at least 90% of maximal. At the low temperature, however, movements were made more slowly. Angular velocities were 1.2- to 1.4-fold lower, and ground contact time was increased by 1.33-fold at 15 degrees C. Average shortening velocity of the SM was only 1.2-fold lower at 15 degrees C than at 25 degrees C. The low Q10 of velocity is in agreement with that predicted for muscles shortening against an inertial load.

Muscle function during jumping in frogs. II. Mechanical properties of muscle: implications for system design

1996 ◽  
Vol 271 (2) ◽  
pp. C571-C578 ◽  
Author(s):  
G. J. Lutz ◽  
L. C. Rome
Keyword(s):  
Sarcomere Length ◽  
Necessary Conditions ◽  
Length Change ◽  
Operating Conditions ◽  
Muscular System ◽  
Maximal Power ◽  
Shortening Velocity ◽  
Semimembranosus Muscle ◽  
Shortening Deactivation

We characterized the design of the frog muscular system for jumping by comparing the properties of isolated muscle with the operating conditions of muscle measured during maximal jumps. During jumping, the semimembranosus muscle (SM) shortened with a V/Vmax (where V is shortening velocity and Vmax is maximal shortening velocity) where 90 and 100% of maximal power would be generated at 15 and 25 degrees C, respectively. To assess the level of activation during jumping, the SM was driven through the in vivo length change and stimulus conditions while the resulting force was measured. The force generated under the in vivo conditions at both temperatures was at least 90% of the force generated at that same V under maximally activated conditions. Thus the SM was nearly maximally activated, and shortening deactivation was minimal. The initial sarcomere length and duration of the stimulus before shortening were important factors that minimized shortening deactivation during jumping. Thus the frog muscular system appears to be designed to meet the three necessary conditions for maximal power generation during jumping: optimal myofilament overlap, optimal V/Vmax, and maximal activation.

scholarly journals Changes in electromyographic activity, mechanical power, and relaxation rates following inspiratory ribcage muscle fatigue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antonio Sarmento ◽  
Guilherme Fregonezi ◽  
Maria Lira ◽  
Layana Marques ◽  
Francesca Pennati ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Low Frequency ◽  
Mechanical Power ◽  
Electromyographic Activity ◽  
Median Frequency ◽  
Relaxation Rates ◽  
Shortening Velocity ◽  
Inspiratory Muscles ◽  
Underlying Mechanisms

AbstractMuscle fatigue is a complex phenomenon enclosing various mechanisms. Despite technological advances, these mechanisms are still not fully understood in vivo. Here, simultaneous measurements of pressure, volume, and ribcage inspiratory muscle activity were performed non-invasively during fatigue (inspiratory threshold valve set at 70% of maximal inspiratory pressure) and recovery to verify if inspiratory ribcage muscle fatigue (1) leads to slowing of contraction and relaxation properties of ribcage muscles and (2) alters median frequency and high-to-low frequency ratio (H/L). During the fatigue protocol, sternocleidomastoid showed the fastest decrease in median frequency and slowest decrease in H/L. Fatigue was also characterized by a reduction in the relative power of the high-frequency and increase of the low-frequency. During recovery, changes in mechanical power were due to changes in shortening velocity with long-lasting reduction in pressure generation, and slowing of relaxation [i.e., tau (τ), half-relaxation time (½RT), and maximum relaxation rate (MRR)] was observed with no significant changes in contractile properties. Recovery of median frequency was faster than H/L, and relaxation rates correlated with shortening velocity and mechanical power of inspiratory ribcage muscles; however, with different time courses. Time constant of the inspiratory ribcage muscles during fatigue and recovery is not uniform (i.e., different inspiratory muscles may have different underlying mechanisms of fatigue), and MRR, ½RT, and τ are not only useful predictors of inspiratory ribcage muscle recovery but may also share common underlying mechanisms with shortening velocity.

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).

CONTRACTILE PROPERTIES OF A HIGH-FREQUENCY MUSCLE FROM A CRUSTACEAN - CONTRACTION KINETICS

1994 ◽  
Vol 187 (1) ◽  
pp. 275-293 ◽  
Author(s):  
D Stokes ◽  
R Josephson
Keyword(s):  
High Frequency ◽  
Isometric Force ◽  
Carcinus Maenas ◽  
Stimulus Frequency ◽  
Length Change ◽  
Shortening Velocity ◽  
Long Duration ◽  
Maximum Isometric Force ◽  
Small Muscle

1. The flagella (small appendages on the maxillipeds) of the crab Carcinus maenas beat regularly when active at about 10 Hz (15 °C). The beat of a flagellum is due to contraction of a single small muscle, the flagellum abductor (FA). The optimal stimulus frequency for tetanic contraction of the FA was about 200 Hz. When the muscle was stimulated at 10 Hz with paired stimuli per cycle, the interstimulus interval that maximized peak force was 2­4 ms, which corresponded well to the interspike intervals within bursts recorded from motor axons during normal beating. 2. Contraction of the isolated FA showed pronounced neuromuscular facilitation and many stimuli were needed to activate the muscle fully. The dependence on facilitation in isolated muscles appeared to be greater than that in vivo. It is suggested that neuromodulators in the blood of the crab enhance neuromuscular transmission and reduce the dependency on facilitation in intact animals. 3. The FA had a narrow length­tension curve. Tetanic tension became vanishingly small at muscle lengths less than about 90 % of the maximum in vivo length. The maximum length change of the muscle during in vivo contraction was about 5 %. 4. The maximum isometric force of the FA was low (about 6 N cm-2) but its shortening velocity was high. Vm, the maximum shortening velocity determined from isotonic shortening, was 4.0 muscle lengths s-1; V0, the maximum shortening velocity from slack test measurements, was about 8 lengths s-1. 5. The structure and physiology of the FA are compared with those of locust flight muscle, chosen because it too is a muscle capable of long-duration, high-frequency performance.

scholarly journals Computational modelling of muscle fibre operating ranges in the hindlimb of a small ground bird (Eudromia elegans), with implications for modelling locomotion in extinct species

2021 ◽  
Vol 17 (4) ◽  
pp. e1008843
Author(s):  
Peter J. Bishop ◽  
Krijn B. Michel ◽  
Antoine Falisse ◽  
Andrew R. Cuff ◽  
Vivian R. Allen ◽  
...  
Keyword(s):  
Muscle Function ◽  
Computational Models ◽  
Fibre Length ◽  
Computational Modelling ◽  
Length Change ◽  
Muscle Fibres ◽  
Extinct Species ◽  
Length Changes ◽  
Experimental Findings

The arrangement and physiology of muscle fibres can strongly influence musculoskeletal function and whole-organismal performance. However, experimental investigation of muscle function during in vivo activity is typically limited to relatively few muscles in a given system. Computational models and simulations of the musculoskeletal system can partly overcome these limitations, by exploring the dynamics of muscles, tendons and other tissues in a robust and quantitative fashion. Here, a high-fidelity, 26-degree-of-freedom musculoskeletal model was developed of the hindlimb of a small ground bird, the elegant-crested tinamou (Eudromia elegans, ~550 g), including all the major muscles of the limb (36 actuators per leg). The model was integrated with biplanar fluoroscopy (XROMM) and forceplate data for walking and running, where dynamic optimization was used to estimate muscle excitations and fibre length changes throughout both gaits. Following this, a series of static simulations over the total range of physiological limb postures were performed, to circumscribe the bounds of possible variation in fibre length. During gait, fibre lengths for all muscles remained between 0.5 to 1.21 times optimal fibre length, but operated mostly on the ascending limb and plateau of the active force-length curve, a result that parallels previous experimental findings for birds, humans and other species. However, the ranges of fibre length varied considerably among individual muscles, especially when considered across the total possible range of joint excursion. Net length change of muscle–tendon units was mostly less than optimal fibre length, sometimes markedly so, suggesting that approaches that use muscle–tendon length change to estimate optimal fibre length in extinct species are likely underestimating this important parameter for many muscles. The results of this study clarify and broaden understanding of muscle function in extant animals, and can help refine approaches used to study extinct species.

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.

scholarly journals Aquatic and terrestrial takeoffs require different hindlimb kinematics and muscle function in mallard ducks

2020 ◽  
Vol 223 (16) ◽  
pp. jeb223743
Author(s):  
Kari R. Taylor-Burt ◽  
Andrew A. Biewener
Keyword(s):  
Muscle Function ◽  
Muscle Power ◽  
Contractile Function ◽  
Shortening Velocity ◽  
Muscle Properties ◽  
Hindlimb Muscle ◽  
Wide Range ◽  
Hindlimb Kinematics ◽  
Metatarsophalangeal Joints

ABSTRACTMallard ducks are capable of performing a wide range of behaviors including nearly vertical takeoffs from both terrestrial and aquatic habitats. The hindlimb plays a key role during takeoffs from both media. However, because force generation differs in water versus on land, hindlimb kinematics and muscle function are likely modulated between these environments. Specifically, we hypothesize that hindlimb joint motion and muscle shortening are faster during aquatic takeoffs, but greater hindlimb muscle forces are generated during terrestrial takeoffs. In this study, we examined the hindlimb kinematics and in vivo contractile function of the lateral gastrocnemius (LG), a major ankle extensor and knee flexor, during takeoffs from water versus land in mallard ducks. In contrast to our hypothesis, we observed no change in ankle angular velocity between media. However, the hip and metatarsophalangeal joints underwent large excursions during terrestrial takeoffs but exhibited almost no motion during aquatic takeoffs. The knee extended during terrestrial takeoffs but flexed during aquatic takeoffs. Correspondingly, LG fascicle shortening strain, shortening velocity and pennation angle change were greater during aquatic takeoffs than during terrestrial takeoffs because of the differences in knee motion. Nevertheless, we observed no significant differences in LG stress or work, but did see an increase in muscle power output during aquatic takeoffs. Because differences in the physical properties of aquatic and terrestrial media require differing hindlimb kinematics and muscle function, animals such as mallards may be challenged to tune their muscle properties for movement across differing environments.

Shortening behavior of the different components of muscle-tendon unit during isokinetic plantar flexions

2013 ◽  
Vol 115 (7) ◽  
pp. 1015-1024 ◽  
Author(s):  
Hugo Hauraix ◽  
Antoine Nordez ◽  
Sylvain Dorel
Keyword(s):  
Range Of Motion ◽  
Triceps Surae ◽  
Myotendinous Junction ◽  
Shortening Velocity ◽  
Movement Velocity ◽  
In Vivo Experiments ◽  
Velocity Relationship ◽  
Angular Velocities ◽  
Gastrocnemius Muscles

The torque-velocity relationship has been widely considered as reflecting the mechanical properties of the contractile apparatus, and the influence of tendinous tissues on this relationship obtained during in vivo experiments remains to be determined. This study describes the pattern of shortening of various muscle-tendon unit elements of the triceps surae at different constant angular velocities and quantifies the contributions of fascicles, tendon, and aponeurosis to the global muscle-tendon unit shortening. Ten subjects performed isokinetic plantar flexions at different preset angular velocities (i.e., 30, 90, 150, 210, 270, and 330°/s). Ultrafast ultrasound measurements were performed on the muscle belly and on the myotendinous junction of the medial and lateral gastrocnemius muscles. The contributions of fascicles, tendon, and aponeurosis to global muscle-tendon unit shortening velocity were calculated for velocity conditions for four parts of the total range of motion. For both muscles, the fascicles' contribution decreased throughout the motion (73.5 ± 21.5% for 100–90° angular range to 33.7 ± 20.2% for 80–70°), whereas the tendon contribution increased (25.8 ± 15.4 to 55.6 ± 16.8%). In conclusion, the tendon contribution to the global muscle-tendon unit shortening is significant even during a concentric contraction. However, this contribution depends on the range of motion analyzed. The intersubject variability found in the maximal fascicle shortening velocity, for a given angular velocity, suggests that some subjects might possess a more efficient musculoarticular complex to produce the movement velocity. These findings are of great interest for understanding the ability of muscle-tendon shortening velocity.

In vivo behavior of the human soleus muscle with increasing walking and running speeds

2015 ◽  
Vol 118 (10) ◽  
pp. 1266-1275 ◽  
Author(s):  
Adrian Lai ◽  
Glen A. Lichtwark ◽  
Anthony G. Schache ◽  
Yi-Chung Lin ◽  
Nicholas A. T. Brown ◽  
...  
Keyword(s):  
Steady State ◽  
Inverse Dynamics ◽  
Length Change ◽  
Shortening Velocity ◽  
Transition Speed ◽  
Muscle Fascicle ◽  
Muscle Fascicles ◽  
Inverse Dynamics Analysis ◽  
Preferred Transition Speed

The interaction between the muscle fascicle and tendon components of the human soleus (SO) muscle influences the capacity of the muscle to generate force and mechanical work during walking and running. In the present study, ultrasound-based measurements of in vivo SO muscle fascicle behavior were combined with an inverse dynamics analysis to investigate the interaction between the muscle fascicle and tendon components over a broad range of steady-state walking and running speeds: slow-paced walking (0.7 m/s) through to moderate-paced running (5.0 m/s). Irrespective of a change in locomotion mode (i.e., walking vs. running) or an increase in steady-state speed, SO muscle fascicles were found to exhibit minimal shortening compared with the muscle-tendon unit (MTU) throughout stance. During walking and running, the muscle fascicles contributed only 35 and 20% of the overall MTU length change and shortening velocity, respectively. Greater levels of muscle activity resulted in increasingly shorter SO muscle fascicles as locomotion speed increased, both of which facilitated greater tendon stretch and recoil. Thus the elastic tendon contributed the majority of the MTU length change during walking and running. When transitioning from walking to running near the preferred transition speed (2.0 m/s), greater, more economical ankle torque development is likely explained by the SO muscle fascicles shortening more slowly and operating on a more favorable portion (i.e., closer to the plateau) of the force-length curve.

Sign in / Sign up

Export Citation Format

Share Document