emg amplitude
Recently Published Documents


TOTAL DOCUMENTS

174
(FIVE YEARS 24)

H-INDEX

37
(FIVE YEARS 2)

Author(s):  
A. K. Kunarbaeva ◽  
A. I. Miroshnichenko ◽  
K. М. Ivanov ◽  
I. V. Miroshnichenko

Aim. To study the functional state of the expiratory muscles in patients with type 2 diabetes mellitus on the basis of changes in their electrical activity when using a functional test with a static expiratory effort. Materials and methods. 47 patients with type 2 diabetes mellitus and 40 patients without disorders of carbohydrate metabolism were examined. To study the electrical activity of the expiratory muscles, surface electromyography (EMG) of the external oblique abdominal muscle (OAM), rectus abdominis muscle (RAM), and internal intercostal muscles (IIM) was performed using a functional test with a static expiratory effort. Results. When performing a functional test with a static expiratory effort in both groups, a decrease in the frequency and an increase in the amplitude of EMG was observed, however, in patients with type 2 diabetes mellitus, these changes were less pronounced. There were also differences in the dynamics of changes in EMG indicators. In patients with type 2 diabetes mellitus, the decrease in the frequency of EMG OAM began from 10 seconds of the test, IIM – from 15 seconds, in the comparison group – from 5 and 10 seconds, respectively. The OAM EMG amplitude in the main group did not change significantly, in the comparison group it increased from 5 seconds of expiratory effort. At the 10th second of the test, the amplitude index of the EMG OAM in patients with type 2 diabetes mellitus was 10.4% lower (p=0.027) than in the comparison group, and at the 15th second – by 10.5% (p=0.033). Conclusion: The change in the electrical activity of the expiratory muscles in patients with type 2 diabetes mellitus is due to the slowed down dynamics of the frequency-amplitude characteristics of the EMG OAM, uncompensated IIM fatigue, as well as lower values of the OAM EMG amplitude when performing a functional exercise test with a static expiratory effort.


Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4051
Author(s):  
Tzu-Yen Huang ◽  
Hoon-Yub Kim ◽  
Gianlorenzo Dionigi ◽  
I-Cheng Lu ◽  
Pi-Ying Chang ◽  
...  

The use of transcartilage (TC) intraoperative neuromonitoring (IONM) in a pediatric population has not been reported. This study evaluated the feasibility and the benefit of using TC-IONM for thyroid cancer surgery in a pediatric population. This retrospective single-center study enrolled 33 pediatric patients who had received an IONM-assisted thyroidectomy. Demographic characteristics, standardized IONM laryngeal examinations and stimulation information (L1-V1-R1-R2-V2-L2) were compared between endotracheal tube (ET) and TC methods. In the 15 cancer patients (30 nerves), TC-IONM provided significant higher electromyography (EMG) amplitude (p < 0.001), signal stability (lower V1/V2 signal correlation, r = 0.955 vs. r = 0.484, p = 0.004), signal quality (higher ratio of V1 or V2 amplitude <500µV, 0.0% vs. 43.8%, p = 0.005) and lower R1-R2p change (7.1% vs. 37.5%, p = 0.049) compared to ET-IONM. In the 18 benign patients (28 nerves), TC-IONM provided significantly higher EMG amplitude (p < 0.001), signal stability (r = 0.945 vs. r = 0.746, p = 0.0324) and non-significant higher signal quality and R1-R2p change. This report is the first to discuss the use of TC-IONM in pediatric thyroid surgery. In contrast with ET-IONM, TC-IONM had superior amplitude, stability and quality of EMG signals, which greatly facilitates the meticulous recurrent laryngeal nerve dissection in pediatric thyroidectomies. The TC-IONM method can be considered a feasible, effective and preferable method of monitored thyroidectomy in pediatric thyroid cancer.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kristine Janssen ◽  
Kangli Deng ◽  
Steve J. A. Majerus ◽  
Dan Li Lin ◽  
Brett Hanzlicek ◽  
...  

AbstractTransurethral and suprapubic catheterization have both been used to test urethral function in rats; however, it is unknown whether these methods affect urethral function or if the order of catheterization affects the results. The aim of this cross-over designed experiment was to compare the effects of catheterization methods and order on leak point pressure (LPP) testing. LPP and simultaneous external urethral sphincter electromyography (EUS EMG) were recorded in anesthetized female virgin Sprague-Dawley rats in a cross-over design to test the effects of transurethral and suprapubic catheterization. There was no significant difference in peak bladder pressure during LPP testing whether measured with a transurethral or suprapubic catheter. There was no significant difference in peak bladder pressure between the first and second catheter insertions. However, peak EMG firing rate, as well as peak EMG amplitude and EMG amplitude difference between peak and baseline were significantly higher after the first catheter insertion compared to the second insertion, regardless of the catheter method. Our results suggest that route of catheterization does not alter urethral function, e.g. create a functional partial outlet obstruction. Either catheterization method could be used for LPP and/or EUS EMG testing in rats.


Author(s):  
Jakob Škarabot ◽  
Thomas Grant Balshaw ◽  
Sumiaki Maeo ◽  
Garry J. Massey ◽  
Marcel Bahia Lanza ◽  
...  

This study compared elbow flexor (EF; Experiment 1) and knee extensor (KE; Experiment 2) maximal compound action potential (Mmax) amplitude between long-term resistance trained (LTRT; n=15 and n=14, 6±3 and 4±1 years of training) and untrained (UT; n=14 and n=49) men; and examined the effect of normalising electromyography (EMG) during maximal voluntary torque (MVT) production to Mmax amplitude on differences between LTRT and UT. EMG was recorded from multiple sites and muscles of EF and KE, Mmax was evoked with percutaneous nerve stimulation, and muscle size was assessed with ultrasonography (thickness, EF) and magnetic resonance imaging (cross-sectional area, KE). Muscle-electrode distance (MED) was measured to account for the effect of adipose tissue on EMG and Mmax. LTRT displayed greater MVT (+66-71%, p<0.001), muscle size (+54-56%, p<0.001), and Mmax amplitudes (+29-60%, p≤0.010) even when corrected for MED (p≤0.045). Mmax was associated with the size of both muscle groups (r≥0.466, p≤0.011). Compared to UT, LTRT had higher absolute voluntary EMG amplitude for the KE (p<0.001), but not the EF (p=0.195), and these differences/similarities were maintained after correction for MED; however, Mmax normalisation resulted in no differences between LTRT and UT for any muscle and/or muscle group (p≥0.652). The positive association between Mmax and muscle size, and no differences when accounting for peripheral electrophysiological properties (EMG/Mmax), indicates the greater absolute voluntary EMG amplitude of LTRT might be confounded by muscle morphology, rather than provide a discrete measure of central neural activity. This study therefore suggests limited agonist neural adaptation after LTRT.


2021 ◽  
pp. 175857322110193
Author(s):  
Katie L Kowalski ◽  
Denise M Connelly ◽  
Jennifer M Jakobi ◽  
Jackie Sadi

Background Push-ups (PU) are a common closed chain exercise used to enhance shoulder girdle stability, with variations that alter the difficulty or target specific muscles. To appropriately select and prescribe PU exercises, an understanding of muscle activity during variations of the PU is needed. The purpose of this scoping review was to identify common PU variations and describe their muscle activation levels. Methods Databases searched included PubMed, CINAHL, Scopus, and SPORTDiscus for articles published between January 2000 and November 2019. Results Three hundred three articles were screened for eligibility with 30 articles included in the analysis. Six PU types and five muscles met the criteria for analysis. Weighted mean electromyography (EMG) amplitude was calculated for each muscle across PU types and for each PU type as a measure of global muscle activity. Triceps and pectoralis major had the highest EMG amplitude during unstable, suspension, incline with hands on a ball and the standard PU. Serratus anterior had the highest EMG amplitude during PU plus and incline PU. The greatest global EMG amplitude occurred during unstable surface PU. Discussion These results provide clinicians with a framework for prescribing PU to target specific muscles and scale exercise difficulty to facilitate rehabilitation outcomes.


Biomechanics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 145-151
Author(s):  
David Alan Phillips ◽  
Angelic Rose Del Vecchio ◽  
Kevin Carroll ◽  
Evan Lee Matthews

Electromyography (EMG) is a research tool used in gait analysis, muscle coordination evaluation, clinical evaluation and sports techniques. Electromyography can provide an insight into neural adaptations, cross education effects, bilateral contraction deficiencies, and antagonist activity in exercise-related movements. While there are clear benefits to using EMG in exercise-related professions, accessibility, cost, and difficulty interpreting the data limit its use in strength and clinical settings. We propose a practical EMG assessment using the isometric squat to identify compensatory activation patterns and report early observations. Ten healthy participants were recruited. Participants performed a 2-min isometric handgrip protocol and an isometric squat protocol. The isometric handgrip was used to identify the expected EMG amplitude response solely due to fatigue. There was a significant increase in EMG amplitude after 2 min (p < 0.05), with the relative increase of 95% CI (1.4%; 27.4%). This indicates the relative increase in EMG amplitude expected if the only influence was fatigue in the 2-min protocol. In the isometric squat protocol, we identified a number of different muscle activation compensation strategies with relative EMG amplitude increases outside of this bandwidth. One subject demonstrated a quadricep compensation strategy with a 188% increase in activation, while reducing activation in both the hamstrings and lower back by 12%. Exercise professionals can use this information to design exercise programs specifically targeting the unloaded muscles during the isometric squat.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Francesca Serafino ◽  
Marco Trucco ◽  
Adele Occhionero ◽  
Giacinto Luigi Cerone ◽  
Alessandro Chiarotto ◽  
...  

Abstract Background Altered regional activation of the lumbar extensors has been previously observed in individuals with low back pain (LBP) performing high-effort and fatiguing tasks. It is currently unknown whether similar alterations can be observed during low-effort functional tasks. Similarly, previous studies did not investigate whether side differences in regional activation are present in individuals with LBP. Finally, there is limited evidence of whether the extent of the alteration of regional activation is associated with clinical factors. Therefore, the aim of this study was to investigate whether individuals with LBP exhibit asymmetric regional activation of the thoraco-lumbar extensor muscles during functional tasks, and if the extent of neuromuscular control alteration is associated with clinical and psychosocial outcome domains. Methods 21 participants with and 21 without LBP performed five functional tasks (gait, sit-to-stand, forward trunk flexion, shoulder flexion and anterior pelvic tilt). The spatial distribution of activation of the thoraco-lumbar extensor muscles was assessed bilaterally using high-density electromyography. For each side, the distribution of electromyographic (EMG) amplitude was characterized in terms of intensity, location and size. Indices of asymmetry were calculated from these features and comparisons between groups and tasks were performed using ANOVA. The features that significantly differed between groups were correlated with self-reported measures of pain intensity and other outcome domains. Results Indices of asymmetry did not differ between participants with and without LBP (p > 0.11). The cranio-caudal location of the activation differed between tasks (p < 0.05), but not between groups (p = 0.64). Participants with LBP showed reduced EMG amplitude during anterior pelvic tilt and loading response phase during gait (both p < 0.05). Pearson correlation revealed that greater pain intensity was associated with lower EMG amplitude for both tasks (R<-0.5, p < 0.05). Conclusions Despite clear differences between tasks, individuals with and without LBP exhibited similar distributions of EMG amplitude during low-effort functional activities, both within and between sides. However, individuals with LBP demonstrated lower activation of the thoraco-lumbar muscles during gait and anterior pelvic tilt, especially those reporting higher pain intensity. These results have implications in the development or refinement of assessment and intervention strategies focusing on motor control in patients with chronic LBP.


Sign in / Sign up

Export Citation Format

Share Document