A validated approach for collecting fine-wire electromyographic recordings in four canine shoulder muscles during highly dynamic tasks

2015 ◽  
Vol 11 (2) ◽  
pp. 65-74 ◽  
Author(s):  
K.L. Cullen ◽  
J.P. Dickey ◽  
S.H.M. Brown ◽  
S.G. Nykamp ◽  
L.R. Bent ◽  
...  

This study investigated the feasibility of obtaining ultrasound-guided intramuscular fine-wire electromyographic (fEMG) recordings from four canine shoulder muscles during highly dynamic activities. Four cadaveric canines were utilised to confirm the appropriate anatomical landmarks and the use of real time ultrasound guidance for electrode placement for four shoulder muscles: Biceps Brachii (BB), Supraspinatus (SP), Infraspinatus (IF), and Triceps Brachii – Long Head (TBLH). Electromyographic activity of the left BB, S P, IF, and TBLH was then recorded in two research dogs while walking and trotting to refine the data collection procedures. Finally, the full experimental protocol was piloted with two client-owned, specially-trained agility dogs, confirming the feasibility of collecting fEMG recordings while performing dynamic, highly-specific agility-related tasks and verifying our EMG amplitude normalisation protocol to enable comparisons across muscles and performance tasks. We present specific guidelines regarding the placement of fEMG electrodes and data collection/normalisation procedures to enable investigations of muscle activation during dynamic activities.

2011 ◽  
Vol 106 (3) ◽  
pp. 1489-1499 ◽  
Author(s):  
Curtis D. Manning ◽  
Parveen Bawa

Torque motor produced stretch of upper limb muscles results in two distinct reflex peaks in the electromyographic activity. Whereas the short-latency reflex (SLR) response is mediated largely by the spinal monosynaptic reflex pathway, the longer-latency reflex (LLR) is suggested to involve a transcortical loop. For the SLRs, patterns of heteronymous monosynaptic Ia connections have been well-studied for a large number of muscles in the cat and in humans. For LLRs, information is available for perturbations to proximal joints, although the protocols for most of these studies did not focus on heteronymous connections. The main objective of the present study was to elicit both SLRs and LLRs in wrist flexors and extensors and to examine heteronymous connections from these muscles to elbow flexors (biceps brachii; BiBr) and extensors (triceps brachii; TriBr) and to selected distal muscles, including abductor pollicis longus (APL), first dorsal interosseous (FDI), abductor digiti minimi (ADM), and Thenars. The stretch of wrist flexors produced SLR and LLR peaks in APL, FDI, ADM, Thenars, and BiBr while simultaneously inducing inhibition of wrist extensors and TriBr. When wrist extensors were stretched, SLR and LLR peaks were observed in TriBr, whereas the primary wrist flexors, APL and BiBr, were inhibited; response patterns of FDI, ADM, and Thenars were less consistent. The main conclusions from the observed data are that: 1) as in the cat, afferents from wrist flexors and extensors make heteronymous connections with proximal and distal upper limb muscles; and 2) the strength of heteronymous connections is greater for LLRs than SLRs in the distal muscles, whereas the opposite is true for the proximal muscles. In the majority of observations, SLR and LLR excitatory peaks were observed together. However, on occasion, LLRs were observed without the SLR response in hand muscles when wrist extensors were stretched.


Author(s):  
Tessy Luger ◽  
Robert Seibt ◽  
Monika Rieger ◽  
Benjamin Steinhilber

We investigated whether physical requirements and motor variability decreased over days in novices during a repetitive screwing task. Fifty-seven subjects performed one hour of repetitive screwing and fastening on three days, separated by 2–7 days. The average physical requirement and relative cycle-to-cycle variability (coefficient of variation, i.e., CV) were calculated from continuous recordings of electromyography of four arm muscles (biceps brachii, triceps brachii, flexor carpi radialis, extensor digitorum), forearm acceleration, and electrocardiography. Muscle activity levels, heart rate, and forearm acceleration decreased from day 1 to day 2 (range: ~4% to ~20%) and/or 3 (range: ~4% to ~28%). Not all muscles showed a similar pattern. Activity of the extensor digitorum and biceps brachii decreased already between days 1 and 2 (range: ~6% to ~13%), whereas activity of the flexor carpi radialis and triceps brachii decreased between days 1 and 3 (range: ~13% to ~20%). No changes in physical requirement were detected between days 2 and 3. Relative motor variability did not change across days, except that variability of forearm acceleration increased from day 1 to 3 (~5%). This study found consistent changes in physical requirements and indicated that several arm muscles show earlier decreases of muscular activity, like the extensor digitorum, compared to other body parts, like the flexor carpi radialis. Moreover, movement strategies may develop differently than muscle activation strategies, based on the different developments of physical requirements and motor variability. The development of physical requirements in industrial tasks is part of daily living and starts at task onset, highlighting the importance of task familiarization and the randomization of experimental conditions in scientific studies.


2011 ◽  
Vol 23 (01) ◽  
pp. 75-82 ◽  
Author(s):  
Yu-Lin Ning ◽  
Jia-Da Li ◽  
Wei-Ching Lo ◽  
Chih-Hung Huang ◽  
Chu-Fen Chang ◽  
...  

Adequate pattern and consistency of the muscle recruitment is essential to symbolize the destruction of the opponent with high movement velocities and precise targeting of the opponent's head and body during a karate jab. The purpose of this study was to evaluate the reaction time (RT), motor time (MT), and total response time (TRT), as well as their correlation during a karate jab, and to investigate the recruitment pattern and consistency of muscles during motor time. As many as 14 professional karate athletes (age: 23.67 ± 2.64 years; height: 174.57 ± 7.13 cm; and weight: 72.75 ± 10.65 kg) participated in the current study. Each subject was instructed to pose in combat stance first and then to use their left hand to jab at an instrumented kicking target as soon as they saw the start signal. Surface electromyograms (EMGs) were recorded from 16 muscles, namely the pronator teres, biceps brachii, triceps brachii, and deltoid of the left upper limb, right erector spinae, left rectus abdominis, and gluteus maximus, rectus femoris, biceps femoris, tibialis anterior, and medial gastrocnemius of the right and left lower limbs. Start and stop signals from the instrumented target were also recorded synchronously to obtain the TRT. Significant correlation between MT and TRT indicated that MT was a key determinant for the TRT of the jab. When performing a karate jab, the karate athletes initiated the movement with postural adjustments of the legs and trunk prior to the onset of the voluntary jab by the upper limb, and with a proximal-to-distal sequence of muscle activation in the left arm. Good consistencies of muscle recruitment of the trunk, left arm, and leg, and cocontraction of the left triceps and biceps brachii also indicated a well-controlled jab by the left arm. These results provide important information on the patterns and the consistencies of the muscle recruitment for coaching a karate jab, which should be helpful for a better understanding of the motor control strategies of a karate jab and for developing a suitable training protocol.


2008 ◽  
Vol 88 (6) ◽  
pp. 703-711 ◽  
Author(s):  
Lars L Andersen ◽  
Michael Kjær ◽  
Christoffer H Andersen ◽  
Peter B Hansen ◽  
Mette K Zebis ◽  
...  

Background and PurposeMuscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this study was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) during selected strengthening exercises in women undergoing rehabilitation for chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia).SubjectsThe subjects were 12 female workers (age=30–60 years) with a clinical diagnosis of trapezius myalgia and a mean baseline pain intensity of 5.6 (range=3–8) on a scale of 0 to 9.MethodElectromyographic activity in the trapezius and deltoid muscles was measured during the exercises (lateral raises, upright rows, shrugs, one-arm rows, and reverse flys) and normalized to EMG activity recorded during a maximal voluntary static contraction (MVC).ResultsFor most exercises, the level of muscle activation was relatively high (>60% of MVC), highlighting the effectiveness and specificity of the respective exercises. For the trapezius muscle, the highest level of muscle activation was found during the shrug (102±11% of MVC), lateral raise (97±6% of MVC), and upright row (85±5% of MVC) exercises, but the latter 2 exercises required smaller training loads (3–10 kg) compared with the shrug exercise (20–30 kg).Discussion and ConclusionThe lateral raise and upright row may be suitable alternatives to shrugs during rehabilitation of chronic neck muscle pain. Several of the strength exercises had high activation of neck and shoulder muscles in women with chronic neck pain. These exercises can be used equally in the attempt to achieve a beneficial treatment effect on chronic neck muscle pain.


1996 ◽  
Vol 12 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Robert U. Newton ◽  
William J. Kraemer ◽  
Keijo Häkkinen ◽  
Brendan J. Humphries ◽  
Aron J. Murphy

The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined 1RM. Performance was significantly higher during the throw movement compared to the press for average velocity, peak velocity, average force, average power, and peak power. Average muscle activity during the concentric phase for pectoralis major, anterior deltoid, triceps brachii, and biceps brachii was higher for the throw condition. It was concluded that performing traditional press movements rapidly with light loads does not create ideal loading conditions for the neuromuscular system with regard to explosive strength production, especially in the final stages of the movement, because ballistic weight loading conditions where the resistance was accelerated throughout the movement resulted in a greater velocity of movement, force output, and EMG activity.


1981 ◽  
Vol 48 (4) ◽  
pp. 163-168 ◽  
Author(s):  
Anthony R. Newall ◽  
Karen L. Robinson ◽  
Sandi J. Spaulding

Bilateral sanding is used by occupational therapists as a therapeutic exercise technique, however, to-date no data have been available identifying the musculature involved in the activity nor the extent of that involvement. The dual purpose of this pilot study was to; (a) delineate the activity of selected shoulder muscles during bilateral sanding, and (b) determine whether the method used would be feasible in the analysis of other therapeutic activities. For this investigation, a quadriplegic individual was matched for height and weight with a normal subject and both were tested under several controlled conditions of bilateral sanding. Right shoulder complex musculature was electromyographically (EMG) investigated and the muscles studied were: pectoralis major, biceps brachii, the three heads of deltoid, and the lateral and medial heads of triceps brachii. EMG data for the two subjects were normalized and represented as percentages of the maximal voluntary contractions (MVC) relative for each muscle. This technique allowed intra- and inter-subject comparisons of muscle activity. Recognizing the limitations of the study with the major one being the small number of subjects, useful information was obtained from the results. The quadriplegic individual appeared to be more inefficient in his muscle usage than the normal subject. This may be related to trunk instability in the quadriplegic subject. All three heads of the deltoid appeared to be the most highly used of monitored muscles in both the normal and the quadriplegic with triceps being only moderately active in the quadriplegic individual. Spring resisted bilateral sanding produced the most EMG activity in all muscles studied in both subjects. Further investigations employing a larger number of subjects may further elucidate EMG activity during bilateral sanding. It would appear that EMG investigations of therapeutic activities offer an informative method of physical activity analysis.


2014 ◽  
Vol 40 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Roland van den Tillaar ◽  
Atle Saeterbakken

Abstract The aim of this study was to examine the effect of fatigue during one set of 6-RM bench pressing upon the muscle patterning and performance. Fourteen resistance-trained males (age 22.5±2.0 years, stature 1.82±0.07 m, body mass 82.0±7.8 kg) conducted a 6-RM bench press protocol. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were measured in each repetition during the 6-RM bench press. Total lifting time increased and the velocity in the ascending movement decreased (p≤0.001). However, the kinematics in the descending phase deferred: the time decreased and velocity increased during the 6-RM (p≤0.001). Generally, muscles increased their EMG amplitude during the six repetitions in the ascending movement, while only three of the seven measured muscles showed an increase over the six repetitions in the descending part in 6-RM bench pressing. It was concluded that the bench pressing performance decreased (lower barbell velocities and longer lifting times) with increasing fatigue in the 6-RM execution. Furthermore EMG increased in the prime movers and the trunk stabilizers (abdominal and spine), while the antagonist muscle (biceps) activity was not affected by fatigue during the lifting phase in a single set of 6-RM bench pressing


Sports ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 224
Author(s):  
Andrea Melani ◽  
Giuliana Gobbi ◽  
Daniela Galli ◽  
Cecilia Carubbi ◽  
Elena Masselli ◽  
...  

Background: The bench press exercise (BP) is commonly practiced in both recreational and professional training. The weight is lowered from a position where the elbows are at a 90° angle at the start and <90° at the end of eccentric phase, and then returned to the elbows extended position. In order to focus the exercise more on the triceps brachii (TB) rather than the pectoralis major (PM), the inter-handle distance (IHD) is decreased diminishing the involvement of the PM in favor of the TB. Purpose: To improve performance of the exercise by reducing force dissociation and transmitting 100% of the external load to the muscle tissue we propose a prototype of the barbell with a bar on which two sleeves are capable of sliding. The dynamic modifications of the IHD keep the elbow flexion angle constant at 90°. Results: Analysis of the inter-handle distance (IHD) signals of the upper body muscles showed a marked increase in muscle activity using the experimental barbell for the PM (19.5%) and for the biceps brachii (173%). Conclusions: The experimental barbell increased the muscle activity typical of the bench press exercise, obtaining the same training induction with a lower load and consequently preventing articular stress.


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 ◽  
...  

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.


2020 ◽  
Vol 13 (1) ◽  
pp. 129-136
Author(s):  
Amin Amini ◽  
Hossein Shirvani ◽  
Behzad Bazgir

Background: Good balance and muscle activity are essential to do daily activities. Recent studies have focused on the relations between balance and attention patterns. The study of the balance and muscle activity of people in different patterns of attention can clarify the nature of the effect of attention instructions. Purpose: The present study aims to evaluate the changes in different focus of attention instructions and quality of balance control and muscle activity in the elderly retired. Methods: Thirty elderly retired men [mean age: 51.6 ± 6.4 years] were recruited for this study. Subjects were selected through the berg balance test. Balance control ability [Biodex Balance System] and muscle activity [electromyography system] were assessed in two conditions, internal attention and external attention task. The data obtained were analyzed using repeated-measures ANOVA at a significant level of P<0.05. Results: Body sway and muscle activity parameters were correlated with different patterns of attention. During external focus condition, [1] Center of Pressure [CoP] total two-leg balance, CoP medio-lateral and CoP anterior-posterior for external-focus were lowered [P<0.05] and [2] Tibialis anterior and soleus for the leg, biceps brachii and triceps brachii for the arm, sternocleidomastoid and semispinalis capitis for external-focus were lowered [P<0.05]. Conclusion: Improved static balance responses and alterations in postural control were observed under external focus conditions. An external focus of attention may be the preferred method for facilitating balance control and muscle activation in an elderly retired man.


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