scholarly journals Muscle Fatigue When Riding a Motorcycle: A Case Study

2021 ◽  
Vol 18 (15) ◽  
pp. 7738
Author(s):  
Priscila Torrado ◽  
Michel Marina ◽  
Stéphane Baudry ◽  
Martín Ríos
Keyword(s):  
Biceps Brachii ◽  
Training Session ◽  
Posterior Part ◽  
Activity Levels ◽  
Triceps Brachii ◽  
Forearm Muscles ◽  
Force Increase ◽  
Flexor Digitorum ◽  
Semg Signals

This case study was conducted to assess muscle pattern, as measured by surface electromyography (sEMG), and its changes during a controlled superbike closed-road track training session. The sEMG signals were recorded unilaterally from biceps brachii (BB), triceps brachii (TB), anterior and posterior part of the deltoid (DA and DP respectively), flexor digitorum superficialis (FS), extensor carpi radialis (CR), extensor digitorum communis (ED) and pectoralis major (PM) during three rounds of 30 min. sEMG signals selected for analysis came from the beginning of the braking action to the way-out of the curves of interest. Considering the laps and rounds as a whole and focusing on the forearm muscles, ED was more systematically (84%) assigned to a state of fatigue than FS (44%) and CR (39%). On the opposite, the TB and DP muscles showed a predominant state of force increase (72%). Whereas the BB showed alternatively a state of fatigue or force increase depending on the side of the curve, when taking into account only the sharpest curves, it showed a predominant state of force increase. In conclusion, the fact that forearm muscles must endure a long-lasting maintenance of considerable activity levels explains why they easily got into a state of fatigue. Moreover, TB and DA are particularly relevant when cornering.

scholarly journals The co-occurrence of a four-headed coracobrachialis muscle, split coracoid process and tunnel for the median and musculocutaneous nerves: the potential clinical relevance of a very rare variation

2020 ◽  
Author(s):  
Łukasz Olewnik ◽  
Nicol Zielinska ◽  
Piotr Karauda ◽  
Fabrice Duparc ◽  
Georgi P. Georgiev ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Morphological Variability ◽  
Coracoid Process ◽  
Triceps Brachii ◽  
Clinical Value ◽  
Medial Head ◽  
Brachialis Muscle ◽  
Present Case Study ◽  
Complex Origin

Abstract The coracobrachialis muscle (CBM) originates from the apex of the coracoid process, in common with the short head of the biceps brachii muscle, and from the intermuscular septum. Both the proximal and distal attachment of the CBM, as well as its relationship with the musculocutaneus nerve demonstrate morphological variability, some of which can lead to many diseases. The present case study presents a new description of a complex origin type (four-headed CBM), as well as the fusion of both the short biceps brachii head, brachialis muscle and medial head of the triceps brachii. In addition, the first and second heads formed a tunnel for the musculocutaneus and median nerves. This case report has clear clinical value due to the split mature of the coracoid process, and is a significant indicator of the development of interest in this overlooked muscle.

scholarly journals Modulation of Stretch Reflexes of the Finger Flexors by Sensory Feedback From the Proximal Upper Limb Poststroke

2009 ◽  
Vol 102 (3) ◽  
pp. 1420-1429 ◽  
Author(s):  
Gilles Hoffmann ◽  
Derek G. Kamper ◽  
Jennifer H. Kahn ◽  
William Z. Rymer ◽  
Brian D. Schmit
Keyword(s):  
Upper Limb ◽  
Stretch Reflex ◽  
Sensory Input ◽  
Biceps Brachii ◽  
Elbow Flexion ◽  
Spinal Reflex ◽  
Reflex Response ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Flexor Digitorum

Neural coupling of proximal and distal upper limb segments may have functional implications in the recovery of hemiparesis after stroke. The goal of the present study was to investigate whether the stretch reflex response magnitude of spastic finger flexor muscles poststroke is influenced by sensory input from the shoulder and the elbow and whether reflex coupling of muscles throughout the upper limb is altered in spastic stroke survivors. Through imposed extension of the metacarpophalangeal (MCP) joints, stretch of the relaxed finger flexors of the four fingers was imposed in 10 relaxed stroke subjects under different conditions of proximal sensory input, namely static arm posture (3 different shoulder/elbow postures) and electrical stimulation (surface stimulation of biceps brachii or triceps brachii, or none). Fast (300°/s) imposed stretch elicited stretch reflex flexion torque at the MCP joints and reflex electromyographic (EMG) activity in flexor digitorum superficialis. Both measures were greatest in an arm posture of 90° of elbow flexion and neutral shoulder position. Biceps stimulation resulted in greater MCP stretch reflex flexion torque. Fast imposed stretch also elicited reflex EMG activity in nonstretched heteronymous upper limb muscles, both proximal and distal. These results suggest that in the spastic hemiparetic upper limb poststroke, sensorimotor coupling of proximal and distal upper limb segments is involved in both the increased stretch reflex response of the finger flexors and an increased reflex coupling of heteronymous muscles. Both phenomena may be mediated through changes poststroke in the spinal reflex circuits and/or in the descending influence of supraspinal pathways.

Shoulder Muscle Activation Levels During the Push-Up-Plus Exercise on Stable and Unstable Surfaces

2017 ◽  
Vol 26 (4) ◽  
pp. 281-286 ◽  
Author(s):  
Rafaela J.B. Torres ◽  
André L.T. Pirauá ◽  
Vinícius Y.S. Nascimento ◽  
Priscila S. dos Santos ◽  
Natália B. Beltrão ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Biceps Brachii ◽  
Emg Activity ◽  
Activity Levels ◽  
Triceps Brachii ◽  
Serratus Anterior ◽  
Upper Trapezius ◽  
Unstable Surface ◽  
Hands And Feet ◽  
Push Up

The aim of this study was to evaluate the acute effect of the use of stable and unstable surfaces on electromyography (EMG) activity and coactivation of the scapular and upper-limb muscles during the push-up plus (with full protraction of the scapula). Muscle activation of anterior deltoid (AD), posterior deltoid (PD), pectoralis major, biceps brachii (BB), triceps brachii (TB), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) levels and coactivation index were determined by surface EMG in 20 young men during push-up plus performed on a stable and unstable condition (2 unstable devices applied to hands and feet). The paired t test and Cohen d were used for statistical analysis. The results showed that during the execution of the push-up plus on the unstable surface an increased EMG activity of the scapular stabilizing muscles (SA, MT, and LT) was observed, while AD and PD muscles showed a decrease. During exercise execution on the unstable surface there was a higher index of coactivation of the scapular muscles (SA–MT and UT–LT pairs). No significant differences were observed in TB–BB and AD–PD pairs. These results suggest that the push-up-plus exercise associated with unstable surfaces produced greater EMG activity levels and coactivation index of the scapular stabilizing muscle. On the other hand, the use of an unstable surface does not promote the same effect for the shoulder muscles.

Shoulder Muscular Activity During Isometric Three-Point Kneeling Exercise on Stable and Unstable Surfaces

2011 ◽  
Vol 27 (3) ◽  
pp. 192-196 ◽  
Author(s):  
Rodrigo Cappato de Araújo ◽  
Rodrigo de Andrade ◽  
Helga Tatiana Tucci ◽  
Jaqueline Martins ◽  
Anamaria Siriani de Oliveira
Keyword(s):  
Biceps Brachii ◽  
Isometric Force ◽  
Muscular Activity ◽  
Activity Levels ◽  
Force Output ◽  
Triceps Brachii ◽  
Serratus Anterior ◽  
Upper Trapezius ◽  
Stable Surface ◽  
Swiss Ball

The purpose of this study was to determine if performing isometric 3-point kneeling exercises on a Swiss ball influenced the isometric force output and EMG activities of the shoulder muscles when compared with performing the same exercises on a stable base of support. Twenty healthy adults performed the isometric 3-point kneeling exercises with the hand placed either on a stable surface or on a Swiss ball. Surface EMG was recorded from the posterior deltoid, pectoralis major, biceps brachii, triceps brachii, upper trapezius, and serratus anterior muscles using surface differential electrodes. All EMG data were reported as percentages of the average root mean square (RMS) values obtained in maximum voluntary contractions for each muscle studied. The highest load value was obtained during exercise on a stable surface. A significant increase was observed in the activation of glenohumeral muscles during exercises on a Swiss ball. However, there were no differences in EMG activities of the scapulothoracic muscles. These results suggest that exercises performed on unstable surfaces may provide muscular activity levels similar to those performed on stable surfaces, without the need to apply greater external loads to the musculoskeletal system. Therefore, exercises on unstable surfaces may be useful during the process of tissue regeneration.

Exploring trainers’ engaging instructional practices: a collective case study

2016 ◽  
Vol 40 (2) ◽  
pp. 111-127 ◽  
Author(s):  
Vishal Arghode ◽  
Jia Wang
Keyword(s):  
Learning Styles ◽  
Learning Outcomes ◽  
Training Session ◽  
Research Area ◽  
Small Sample ◽  
Training Context ◽  
Content Type ◽  
Collective Case Study ◽  
Study Approach

Purpose – This study aims to explore the phenomenon of training engagement from the trainers’ perspective. Specifically, two questions guided this inquiry. First, how do trainers define engagement in the training context? and What strategies do trainers use to engage trainees? Design/methodology/approach – The collective case study approach was adopted for this qualitative study. Seven cases were selected for in-depth analyses. Data were collected through individual, face-to-face interviews and analyzed using the constant comparative analysis method. Findings – Major findings suggest that engaging training practices take various forms. They include being trainee-centered, maximizing learning through entertaining and interesting instruction, accommodating different learning styles, eliciting trainee participation by creating an encouraging learning environment and connecting with trainees by building rapport early in a training session. Research limitations/implications – The small sample limits the generalizability of the findings. However, this study expands training literature by focusing on an under-explored research area, the role of engaging trainees in maximizing learning outcomes. Practical implications – For trainers, this study offered some specific strategies they can use to engage learners in the training context to achieve desired learning outcomes. In addition, the seven cases selected for this study may be used as a benchmark against which both experienced and novice trainers compared their own practices. Originality/value – This is one of very few qualitative studies with a focus on emotional aspects involved in training. The rich data from this study shed light on areas for future improvement, particularly regarding how to effectively engage trainees to maximize learning outcomes.

Electrical activity and relative length changes of dog limb muscles as a function of speed and gait

1981 ◽  
Vol 94 (1) ◽  
pp. 15-42 ◽  
Author(s):  
G. E. Goslow ◽  
H. J. Seeherman ◽  
C. R. Taylor ◽  
M. N. McCutchin ◽  
N. C. Heglund
Keyword(s):  
Electrical Activity ◽  
Stance Phase ◽  
Biceps Brachii ◽  
Vastus Lateralis ◽  
Activity Patterns ◽  
Relative Length ◽  
Muscular Activity ◽  
Triceps Brachii ◽  
Limb Muscles ◽  
Length Changes

Electrical activity and length changes of 11 muscles of the fore- and hind- limbs of dogs walking, running, and galloping on a treadmill, were measured as a function of forward speed and gait. Our purpose was to find out whether the activity patterns of the major limb muscles were consistent with the two mechanisms proposed for storage and recovery of energy within a stride: a ‘pendulum-like’ mechanism during a walk, and a ‘spring-like’ mechanism during a run. In the stance phase of the walking dog, we found that the supraspinatus, long head of the triceps brachii, biceps brachii, vastus lateralis, and gastrocnemius underwent only minor length changes during a relatively long portion of their activity, Thus, a major part of their activity during the walk seems consistent with a role in stabilization of the joints as the dog ‘pole-vaulted’ over its limbs (and thereby conserved energy). In the stance phase of trotting and/or galloping dogs, we found that the supraspinatus, lateral head of the triceps, vastus lateralis, and gastrocnemius were active while being stretched prior to shortening (as would be required for elastic storage of energy), and that this type of activity increased with increasing speed. We also found muscular activity in the select limb flexors that was consistent with storage of kinetic energy at the end of the swing phase and recovery during the propulsive stroke. This activity pattern was apparent in the latissimus dorsi during a walk and trot, and in the biceps femoris during a trot and gallop. We conclude that, during locomotion, a significant fraction of the electrical activity of a number of limbs muscles occurs while they undergo little or no length change or are being stretched prior to shortening and that these types of activities occur in a manner that would enable the operation of pendulum-like and spring-like mechanisms for conserving energy within a stride. Therefore these forms of muscular activity, in addition to the more familiar activity associated with muscle shortening, should be considered to be important during locomotion.

Dynamic contraction and fatigue analysis in biceps brachii muscles using synchrosqueezed wavelet transform and singular value features

2021 ◽  
pp. 095441192110480
Author(s):  
Lakshmi M Hari ◽  
Gopinath Venugopal ◽  
Swaminathan Ramakrishnan
Keyword(s):  
Wavelet Transform ◽  
Biceps Brachii ◽  
Singular Value ◽  
Time Frequency ◽  
Singular Value Decomposition Method ◽  
Dynamic Contractions ◽  
Synchrosqueezed Wavelet Transform ◽  
Value Decomposition ◽  
Neuromuscular Conditions ◽  
Semg Signals

In this study, the dynamic contractions and the associated fatigue condition in biceps brachii muscle are analysed using Synchrosqueezed Wavelet Transform (SST) and singular value features of surface Electromyography (sEMG) signals. For this, the recorded signals are decomposed into time-frequency matrix using SST. Two analytic functions namely Morlet and Bump wavelets are utilised for the analysis. Singular Value Decomposition method is applied to this time-frequency matrix to derive the features such as Maximum Singular Value (MSV), Singular Value Entropy (SVEn) and Singular Value Energy (SVEr). The results show that both these wavelets are able to characterise nonstationary variations in sEMG signals during dynamic fatiguing contractions. Increase in values of MSV and SVEr with the progression of fatigue denotes the presence of nonstationarity in the sEMG signals. The lower values of SVEn with the progression of fatigue indicate the randomness in the signal. Thus, it appears that the proposed approach could be used to characterise dynamic muscle contractions under varied neuromuscular conditions.

scholarly journals Nandrolone increases angiotensin-I converting enzyme activity in rats tendons

2015 ◽  
Vol 21 (3) ◽  
pp. 173-177 ◽  
Author(s):  
Rita de Cassia Marqueti ◽  
Nara Yumi Hashimoto ◽  
João Luiz Quaglioti Durigan ◽  
Lívia Larissa Batista e Silva ◽  
Jeeser Alves de Almeida ◽  
...  
Keyword(s):  
Training Session ◽  
Renin Angiotensin System ◽  
Tissue Growth ◽  
Control Group ◽  
Activity Levels ◽  
Converting Enzyme ◽  
Angiotensin I ◽  
Angiotensin I Converting Enzyme ◽  
Tendon Adaptation ◽  
Ace Activity

INTRODUCTION: The renin-angiotensin system (RAS) has been associated with several biological processes of the human body, regulating, among others blood pressure and water and electrolytes balance. Moreover, RAS also regulates connective tissue growth. Recently, studies have shown that the use of nandrolone modifies the angiotensin-I converting enzyme (ACE) activity and increases collagen deposition in the heart. OBJECTIVE: The aim of study was to evaluate the Angiotensin-I converting enzyme (ACE) activity in the superficial flexor tendon (SFT) and in serum after load exercise in combination with anabolic androgenic steroid (AAS) administration after training session and six weeks of detraining. METHODS: Forty-eight Wistar rats were used into two groups (G1 and G2) subdivided into four subgroups: Sedentary (S); trained (T); AAS-treated (Deca-Durabolin(r), 5mg/kg, twice a week) sedentary rats (AAS) and AAS-treated and trained animals (AAST). Trained groups performed jumps in water: four series of 10 jumps each, followed by a 30 sec interval between the series, for seven weeks. RESULTS: Training increased ACE activity in the SFT compared to the control group (p <0.05). Both AAS and AAST groups presented higher ACE activity levels (p < 0.05). The AAST increased the ACE activity only compared to the trained animals. Only the AAST group presented significant higher levels of ACE in the serum. In the G2 group, all experimental groups presented decreased ACE activity in the serum and in the tendon, as compared to the control group. CONCLUSION: This study indicates that AAS administration and its combination with exercise increased ACE activity of tendons. AAS abuse could compromise tendon adaptation causing maladaptive remodeling.

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