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

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.

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.

High-fat diet-induced splenic, hepatic, and skeletal muscle architecture damage: cellular and molecular players

2021 ◽  
Author(s):  
Ambreen Asghar ◽  
Tasleem Akhtar ◽  
Tayyeba Batool ◽  
Muhammad Babar Khawar ◽  
Sania Nadeem ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
High Fat Diet ◽  
Muscle Architecture ◽  
High Fat

scholarly journals Correlation between age, muscle architecture, and muscle strength in children with Erb’s palsy

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Ahmed Saad Awad ◽  
Mostafa Soliman Ali ◽  
Mohamed Ismail Elassal
Keyword(s):  
Muscle Strength ◽  
Muscle Weakness ◽  
Muscle Thickness ◽  
Study Groups ◽  
Pennation Angle ◽  
Muscle Architecture ◽  
Active Movement ◽  
Significant Relation ◽  
Erb’S Palsy ◽  
Significant Difference

Abstract Background Muscle weakness is a widespread problem in children with Erb’s palsy as it can cause changes in muscle architecture parameters, which can be detected by ultrasonography. This study was conducted to determine the relation between age, muscle architecture, and muscle strength in children with Erb’s palsy. A total of 40 children with Erb’s palsy from both sexes aged 1–2.5 years were included in this study. Muscle thickness and pennation angle were measured by ultrasonography, and muscle strength was measured using the active movement scale. Results A significant relation was found between age, muscle thickness, pennation angle, and muscle strength (P < 0.05). Moreover, a significant difference was found in muscle architecture parameters during relaxation and contraction in both study groups and in each study group (P < 0.05). Conclusion Muscle weakness in children with Erb’s palsy has an effect on muscle architecture parameters, and these parameters also increase with age.

scholarly journals Effects of botulinum toxin-A on the muscle architecture of stroke patients: The First Ultrasonographic study

2011 ◽  
Vol 43 (11) ◽  
pp. 1016-1019 ◽  
Author(s):  
F Tok ◽  
L Özçakar ◽  
İ Safaz ◽  
R Alaca
Keyword(s):  
Botulinum Toxin ◽  
Botulinum Toxin A ◽  
Muscle Architecture ◽  
Stroke Patients ◽  
Toxin A

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

A Comparison of Rat Extensor digitorum longus and Gastrocnemius medialis Muscle Architecture and Length-Force Characteristics

1994 ◽  
Vol 149 (2) ◽  
pp. 111-120 ◽  
Author(s):  
P.A. Huijing ◽  
S.M. Nieberg ◽  
E.A.v.d. Veen ◽  
G.J.C. Ettema
Keyword(s):  
Extensor Digitorum Longus ◽  
Muscle Architecture ◽  
Extensor Digitorum ◽  
Gastrocnemius Medialis ◽  
Force Characteristics

Mathematical analysis of a muscle architecture model

2009 ◽  
Vol 217 (1) ◽  
pp. 64-76 ◽  
Author(s):  
Javier Navallas ◽  
Armando Malanda ◽  
Luis Gila ◽  
Javier Rodríguez ◽  
Ignacio Rodríguez
Keyword(s):  
Mathematical Analysis ◽  
Muscle Architecture ◽  
Architecture Model

scholarly journals The influence of muscle pennation angle and cross-sectional area on contact forces in the ankle joint

2016 ◽  
Vol 52 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Ran S Sopher ◽  
Andrew A Amis ◽  
D Ceri Davies ◽  
Jonathan RT Jeffers
Keyword(s):  
Pennation Angle ◽  
Muscle Architecture ◽  
Cross Sectional Area ◽  
Contact Forces ◽  
Sectional Area ◽  
Muscle Forces ◽  
Cross Sectional ◽  
Contact Loads ◽  
The Mean ◽  
And Function

Data about a muscle’s fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.

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