Twitch characteristics in relation to muscle architecture and actual muscle length

1984 ◽  
Vol 401 (4) ◽  
pp. 374-379 ◽  
Author(s):  
R. D. Woittiez ◽  
P. A. Huijing ◽  
R. H. Rozendal
Keyword(s):  
Muscle Length ◽  
Muscle Architecture ◽  
Twitch Characteristics

Incorporation of muscle architecture into the muscle length-tension relationship

1989 ◽  
Vol 22 (8-9) ◽  
pp. 943-948 ◽  
Author(s):  
Kenton R. Kaufman ◽  
Kai-Nan An ◽  
Edmund Y.S. Chao
Keyword(s):  
Muscle Length ◽  
Muscle Architecture

scholarly journals Estimation of the force–velocity properties of individual muscles from measurement of the combined plantarflexor properties

2020 ◽  
Vol 223 (18) ◽  
pp. jeb219980
Author(s):  
Mehrdad Javidi ◽  
Craig P. McGowan ◽  
David C. Lin
Keyword(s):  
Muscle Length ◽  
Muscle Architecture ◽  
Muscle Group ◽  
Cross Sectional ◽  
Fiber Properties ◽  
Group Modeling ◽  
Force Velocity ◽  
The Individual

ABSTRACTThe force–velocity (F–V) properties of isolated muscles or muscle fibers have been well studied in humans and other animals. However, determining properties of individual muscles in vivo remains a challenge because muscles usually function within a synergistic group. Modeling has been used to estimate the properties of an individual muscle from the experimental measurement of the muscle group properties. While this approach can be valuable, the models and the associated predictions are difficult to validate. In this study, we measured the in situ F–V properties of the maximally activated kangaroo rat plantarflexor group and used two different assumptions and associated models to estimate the properties of the individual plantarflexors. The first model (Mdl1) assumed that the percent contributions of individual muscles to group force and power were based upon the muscles' cross-sectional area and were constant across the different isotonic loads applied to the muscle group. The second model (Mdl2) assumed that the F–V properties of the fibers within each muscle were identical, but because of differences in muscle architecture, the muscles' contributions to the group properties changed with isotonic load. We compared the two model predictions with independent estimates of the muscles' contributions based upon sonomicrometry measurements of muscle length. We found that predictions from Mdl2 were not significantly different from sonomicrometry-based estimates while those from Mdl1 were significantly different. The results of this study show that incorporating appropriate fiber properties and muscle architecture is necessary to parse the individual muscles' contributions to the group F–V properties.

scholarly journals How does passive lengthening change the architecture of the human medial gastrocnemius muscle?

2017 ◽  
Vol 122 (4) ◽  
pp. 727-738 ◽  
Author(s):  
Bart Bolsterlee ◽  
Arkiev D’Souza ◽  
Simon C. Gandevia ◽  
Robert D. Herbert
Keyword(s):  
Diffusion Tensor ◽  
Muscle Fibers ◽  
Three Dimensional ◽  
Muscle Length ◽  
Muscle Architecture ◽  
Medial Gastrocnemius ◽  
Fascicle Length ◽  
Muscle Belly ◽  
Whole Muscle

There are few comprehensive investigations of the changes in muscle architecture that accompany muscle contraction or change in muscle length in vivo. For this study, we measured changes in the three-dimensional architecture of the human medial gastrocnemius at the whole muscle level, the fascicle level and the fiber level using anatomical MRI and diffusion tensor imaging (DTI). Data were obtained from eight subjects under relaxed conditions at three muscle lengths. At the whole muscle level, a 5.1% increase in muscle belly length resulted in a reduction in both muscle width (mean change −2.5%) and depth (−4.8%). At the fascicle level, muscle architecture measurements obtained at 3,000 locations per muscle showed that for every millimeter increase in muscle-tendon length above the slack length, average fascicle length increased by 0.46 mm, pennation angle decreased by 0.27° (0.17° in the superficial part and 0.37° in the deep part), and fascicle curvature decreased by 0.18 m−1. There was no evidence of systematic variation in architecture along the muscle’s long axis at any muscle length. At the fiber level, analysis of the diffusion signal showed that passive lengthening of the muscle increased diffusion along fibers and decreased diffusion across fibers. Using these measurements across scales, we show that the complex shape changes that muscle fibers, whole muscles, and aponeuroses of the medial gastrocnemius undergo in vivo cannot be captured by simple geometrical models. This justifies the need for more complex models that link microstructural changes in muscle fibers to macroscopic changes in architecture. NEW & NOTEWORTHY Novel MRI and DTI techniques revealed changes in three-dimensional architecture of the human medial gastrocnemius during passive lengthening. Whole muscle belly width and depth decreased when the muscle lengthened. Fascicle length, pennation, and curvature changed uniformly or near uniformly along the muscle during passive lengthening. Diffusion of water molecules in muscle changes in the same direction as fascicle strains.

Relationship Between Muscle Architecture and Joint Performance During Concentric Contractions in Humans

2013 ◽  
Vol 29 (4) ◽  
pp. 405-412 ◽  
Author(s):  
Taku Wakahara ◽  
Hiroaki Kanehisa ◽  
Yasuo Kawakami ◽  
Tetsuo Fukunaga ◽  
Toshimasa Yanai
Keyword(s):  
Angular Velocity ◽  
Muscle Length ◽  
Magnetic Resonance Images ◽  
Muscle Architecture ◽  
Muscle Volume ◽  
Joint Torque ◽  
Shortening Velocity ◽  
Joint Power ◽  
Joint Performance ◽  
Concentric Contractions

The purpose of this study was to examine the relationship between muscle architecture of the triceps brachii (TB) and joint performance during concentric elbow extensions. Twenty-two men performed maximal isometric and concentric elbow extensions against various loads. Joint torque and angular velocity during concentric contractions were measured, and joint power was calculated. Muscle length, cross-sectional areas, and volume of TB were measured from magnetic resonance images. Pennation angle (PA) of TB at rest was determined by ultrasonography. The PA was significantly correlated with the maximal isometric torque (r= .471), but not to the torque normalized by muscle volume (r= .312). A significant correlation was found between PA and the angular velocity at 0 kg load (r= .563), even when the angular velocity was normalized by the muscle length (r= .536). The PA was significantly correlated with the maximal joint power (r= .519), but not with the power normalized by muscle volume (r= .393). These results suggest that PA has a positive influence on the muscle shortening velocity during an unloaded movement, but does not have a significant influence on the maximum power generation in untrained men.

Morphological Basis of the Disparity Between Muscle Length and Sarcomere Length in the Myocardium

1973 ◽  
Vol 31 ◽  
pp. 422-423
Author(s):  
G.E. Adomian ◽  
L. Chuck ◽  
W.W. Pannley
Keyword(s):  
Cardiac Muscle ◽  
Sarcomere Length ◽  
Muscle Length ◽  
Contractile Force ◽  
Direct Function ◽  
Morphological Basis ◽  
Tension Curve

Sonnenblick, et al, have shown that sarcomeres change length as a function of cardiac muscle length along the ascending portion of the length-tension curve. This allows the contractile force to be expressed as a direct function of sarcomere length. Below L max, muscle length is directly related to sarcomere length at lengths greater than 85% of optimum. However, beyond the apex of the tension-length curve, i.e. L max, a disparity occurs between cardiac muscle length and sarcomere length. To account for this disproportionate increase in muscle length as sarcomere length remains relatively stable, the concept of fiber slippage was suggested as a plausible explanation. These observations have subsequently been extended to the intact ventricle.

scholarly journals Insights into the combination of neuromuscular electrical stimulation and motor imagery in a training-based approach

2021 ◽  
Author(s):  
Amandine Bouguetoch ◽  
Alain Martin ◽  
Sidney Grosprêtre
Keyword(s):  
Electrical Stimulation ◽  
Motor Imagery ◽  
Neural Plasticity ◽  
Neuromuscular Electrical Stimulation ◽  
Voluntary Contraction ◽  
Muscle Architecture ◽  
Fascicle Length ◽  
Before And After ◽  
V Wave ◽  
And Control

Abstract Introduction Training stimuli that partially activate the neuromuscular system, such as motor imagery (MI) or neuromuscular electrical stimulation (NMES), have been previously shown as efficient tools to induce strength gains. Here the efficacy of MI, NMES or NMES + MI trainings has been compared. Methods Thirty-seven participants were enrolled in a training program of ten sessions in 2 weeks targeting plantar flexor muscles, distributed in four groups: MI, NMES, NMES + MI and control. Each group underwent forty contractions in each session, NMES + MI group doing 20 contractions of each modality. Before and after, the neuromuscular function was tested through the recording of maximal voluntary contraction (MVC), but also electrophysiological and mechanical responses associated with electrical nerve stimulation. Muscle architecture was assessed by ultrasonography. Results MVC increased by 11.3 ± 3.5% in NMES group, by 13.8 ± 5.6% in MI, while unchanged for NMES + MI and control. During MVC, a significant increase in V-wave without associated changes in superimposed H-reflex has been observed for NMES and MI, suggesting that neural adaptations occurred at supraspinal level. Rest spinal excitability was increased in the MI group while decreased in the NMES group. No change in muscle architecture (pennation angle, fascicle length) has been found in any group but muscular peak twitch and soleus maximal M-wave increased in the NMES group only. Conclusion Finally, MI and NMES seem to be efficient stimuli to improve strength, although both exhibited different and specific neural plasticity. On its side, NMES + MI combination did not provide the expected gains, suggesting that their effects are not simply cumulative, or even are competitive.

Grasping behavior in the white‐tailed sea eagle (Accipitridae, Aves) explained by muscle architecture

2021 ◽  
Author(s):  
María Clelia Mosto ◽  
G. H. Cassini ◽  
M. B. J. Picasso ◽  
O. Krone
Keyword(s):  
Muscle Architecture

Chronic Adaptations of the Posterior Rotator Cuff in Professional Pitchers

2021 ◽  
pp. 036354652098868
Author(s):  
Stephen J. Thomas ◽  
Justin Cobb ◽  
Scott Sheridan ◽  
Joseph Rauch ◽  
Ryan W. Paul
Keyword(s):  
Soft Tissue ◽  
Rotator Cuff ◽  
Internal Rotation ◽  
External Rotation ◽  
Negative Relationship ◽  
Muscle Thickness ◽  
Pennation Angle ◽  
Muscle Architecture ◽  
Infraspinatus Muscle ◽  
Teres Minor

Background: Because of the large forces and high frequency of throwing, the upper extremity experiences repetitive stresses that lead to acute and chronic adaptations. While the importance of pennation angle and muscle thickness as predictors of muscle force production has been shown in other populations and other joints, there has been little research done that examines these variables in the shoulders of baseball players. Purpose: (1) To examine the chronic effect pitching has on the rotator cuff muscle architecture (pennation angle and muscle thickness) in healthy professional baseball pitchers, and (2) to examine the correlation between muscle architecture and clinical measures of strength and range of motion (ROM). Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-eight healthy professional pitchers were recruited during the 2019 spring training. Internal rotation (IR) and external rotation (ER) strength were measured with a handheld dynamometer and IR and ER ROM were measured with an inclinometer. A diagnostic ultrasound machine was utilized to capture images of humeral retroversion, as well as the pennation angle and muscle thickness of the infraspinatus and teres minor muscles. ImageJ software was used to quantify the pennation angle and muscle thickness. Results: There were no significant differences between the dominant and nondominant arms for ER or IR strength. Also, no pennation angle and muscle thickness differences were found between the dominant and nondominant arms. A weak positive relationship between infraspinatus muscle thickness (superficial and total) and ER strength ( P = .016, R = 0.287 and P = .009, R = 0.316) and a moderate negative relationship between soft tissue glenohumeral internal rotation deficit (GIRD) and the bilateral difference of the teres minor deep pennation angle ( R = −0.477, P = .008) were observed. No other significant relationships were noted. Conclusion: Our results are contrary to current literature as we expected to see a stronger dominant arm, with a larger pennation angle and greater muscle thickness. Interestingly, we found that ER strength was positively related to only the thickness of the infraspinatus muscle, and that soft tissue GIRD was positively related to only the side-to-side adaptation of the pennation angle within the deep portion of the teres minor. This suggests that when posterior shoulder tightness occurs, specifically the architecture of the teres minor muscle is involved. However, the organization to which these players belonged has a very extensive training protocol throughout the year that emphasizes bilateral training during a large majority of the exercises. Therefore, the results may not be generalizable to all professional players.

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