scholarly journals Effects of Rehearsal Time and Repertoire Speed on Extensor Carpi Radialis EMG in Conservatory Piano Students

2020 ◽  
Vol 35 (2) ◽  
pp. 81-88
Author(s):  
Jean-Pierre Baeyens ◽  
Ben Serrien ◽  
Maggie Goossens ◽  
Katia Veekmans ◽  
Regs Baeyens ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Lateral Epicondylitis ◽  
Mean Amplitude ◽  
Frequency Component ◽  
Voluntary Contraction ◽  
Semg Signal ◽  
Piano Etudes ◽  
Piano Students ◽  
Forearm Muscles ◽  
Extensor Carpi Radialis

BACKGROUND: Repetitive actions while playing piano may overload forearm muscles and tendons, leading to playing-related musculoskeletal disorders (PRMDs), including lateral epicondylitis. METHODS: In this pilot study, surface electromyography (sEMG) activity of the extensor carpi radialis (ECR) was captured in 10 conservatory piano students while playing a fast and a slow music score selected from the individual’s repertoire, each 3 minutes long. Measurements were made at baseline and again after 2 hrs and 4 hrs of rehearsal time of the piano études. The amplitude of the sEMG signal was processed by a smoothing algorithm, and the frequency component with a non-orthogonal wavelets procedure. Amplitude of the sEMG was expressed in percent of maximal voluntary contraction (%MVC) at baseline. Statistical analysis encompassed 2-way repeated measures ANOVAs for the amplitude and frequency components of the sEMG signal (a set at 5%). The students also rated the intensity of rehearsals using a VAS. RESULTS: The ECR presented with a mean amplitude of 23%MVC for the slow scores, which increased significantly to 36%MVC for the fast scores. The sEMG signal presented a significant though small decrease of 1.9%MVC in amplitude between baseline and 4 hrs of rehearsal time and no shift in frequency, which may indicate that the rehearsals were held at a physiological steady-state and suggesting optimization or complementary muscle loading. CONCLUSIONS: These data accentuated that the loading of the ECR (as reflected in the amplitude component) was higher than that seen for computer keyboard workers. The augmented loading of the ECR and reduced blood flow to forearm muscles may be a factor in the development of PRMDs in pianists.

scholarly journals Effects of Ultrasound-Guided Administration of Botulinum Toxin (IncobotulinumtoxinA) in Patients with Lateral Epicondylitis

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 46 ◽  
Author(s):  
Antonio Galván Ruiz ◽  
Gloria Vergara Díaz ◽  
Beatriz Rendón Fernández ◽  
Carmen Echevarría Ruiz De Vargas
Keyword(s):  
Adverse Events ◽  
Repeated Measures ◽  
Patient Population ◽  
Lateral Epicondylitis ◽  
Ultrasound Guided ◽  
Repeated Measures Analysis ◽  
Secondary Analyses ◽  
Males And Females ◽  
Post Hoc ◽  
Extensor Carpi Radialis

How effective and safe are incobotulinumtoxinA injections in adult patients with lateral epicondylitis refractory to other treatments? In this experimental study, ultrasound-guided incobotulinumtoxinA 10–30 U/muscle was injected into extensor carpi ulnaris, extensor digiti minimi, extensor digitorum longus and extensor carpi radialis brevis muscles. Pain (visual analogue scale [VAS], 0 to 10 [no pain to severe pain]) and upper-limb functionality (QuickDASH scale, 0 to 100 [best to worst]), assessed at baseline, 1, 3 and 6 months post-treatment, were analysed using repeated-measures analysis of variance (ANOVA) and Tukey post-hoc tests. Secondary analyses stratifying patient population by sex and baseline VAS were performed. Adverse events were reported. Twenty-four patients (mean [standard deviation] age 46.8 years) were included. Compared with baseline, mean VAS and QuickDASH scores improved at all follow-ups (p < 0.001 and p = 0.001, respectively; repeated-measures ANOVA). Secondary analyses revealed significant differences between baseline and all follow-ups in the group with baseline VAS ≥ 6 and in males and females (all p < 0.05, Tukey post-hoc test). No adverse events, except for the expected third finger weakness, were reported. In conclusion, ultrasound-guided incobotulinumtoxinA injections may be an effective treatment for lateral epicondylitis in the appropriate patient population.

scholarly journals Autologous Blood Injection and Wrist Immobilisation for Chronic Lateral Epicondylitis

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Nicola Massy-Westropp ◽  
Stuart Simmonds ◽  
Suzanne Caragianis ◽  
Andrew Potter
Keyword(s):  
Tennis Elbow ◽  
Autologous Blood ◽  
Lateral Epicondylitis ◽  
Contralateral Limb ◽  
Cortisone Injection ◽  
Autologous Blood Injection ◽  
Blood Injection ◽  
And Function ◽  
Prospective Longitudinal ◽  
Extensor Carpi Radialis

Purpose. This study explored the effect of autologous blood injection (with ultrasound guidance) to the elbows of patients who had radiologically assessed degeneration of the origin of extensor carpi radialis brevis and failed cortisone injection/s to the lateral epicondylitis.Methods. This prospective longitudinal series involved preinjection assessment of pain, grip strength, and function, using the patient-rated tennis elbow evaluation. Patients were injected with blood from the contralateral limb and then wore a customised wrist support for five days, after which they commenced a stretching, strengthening, and massage programme with an occupational therapist. These patients were assessed after six months and then finally between 18 months and five years after injection, using the patient-rated tennis elbow evaluation.Results. Thirty-eight of 40 patients completed the study, showing significant improvement in pain; the worst pain decreased by two to five points out of a 10-point visual analogue for pain. Self-perceived function improved by 11–25 points out of 100. Women showed significant increase in grip, but men did not.Conclusions. Autologous blood injection improved pain and function in a worker’s compensation cohort of patients with chronic lateral epicondylitis, who had not had relief with cortisone injection.

Blockade of 5-HT2 receptors suppresses rate of torque development and motor unit discharge rate during rapid contractions

2021 ◽  
Author(s):  
Benjamin Ian Goodlich ◽  
Sean A Horan ◽  
Justin J Kavanagh
Keyword(s):  
Motor Unit ◽  
Unit Activity ◽  
Repeated Measures ◽  
Discharge Rate ◽  
Voluntary Contraction ◽  
Unit Discharge ◽  
Motor Unit Activity ◽  
Rate Of Torque Development ◽  
Motor Unit Discharge ◽  
Torque Development

Serotonin (5-HT) is a neuromodulator that is critical for regulating the excitability of spinal motoneurons and the generation of muscle torque. However, the role of 5-HT in modulating human motor unit activity during rapid contractions has yet to be assessed. Nine healthy participants (23.7 ± 2.2 yr) ingested 8 mg of the competitive 5-HT2 antagonist cyproheptadine in a double-blinded, placebo-controlled, repeated-measures experiment. Rapid dorsiflexion contractions were performed at 30%, 50% and 70% of maximal voluntary contraction (MVC), where motor unit activity was assessed by high-density surface electromyographic decomposition. A second protocol was performed where a sustained, fatigue-inducing dorsiflexion contraction was completed prior to undertaking the same 30%, 50% and 70% MVC rapid contractions and motor unit analysis. Motor unit discharge rate (p < 0.001) and rate of torque development (RTD; p = 0.019) for the unfatigued muscle were both significantly lower for the cyproheptadine condition. Following the fatigue inducing contraction, cyproheptadine reduced motor unit discharge rate (p < 0.001) and RTD (p = 0.024), where the effects of cyproheptadine on motor unit discharge rate and RTD increased with increasing contraction intensity. Overall, these results support the viewpoint that serotonergic effects in the central nervous system occur fast enough to regulate motor unit discharge rate during rapid powerful contractions.

Direct effect of PaCO2 on respiratory sinus arrhythmia in conscious humans

2002 ◽  
Vol 282 (3) ◽  
pp. H973-H976 ◽  
Author(s):  
Nobuko Sasano ◽  
Alex E. Vesely ◽  
Junichiro Hayano ◽  
Hiroshi Sasano ◽  
Ron Somogyi ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Direct Effect ◽  
Respiratory Sinus Arrhythmia ◽  
Random Order ◽  
Mean Amplitude ◽  
Frequency Component ◽  
Pulmonary Gas Exchange ◽  
High Frequency Component ◽  
Sinus Arrhythmia ◽  
End Tidal

Respiratory sinus arrhythmia (RSA) may improve the efficiency of pulmonary gas exchange by matching the pulmonary blood flow to lung volume during each respiratory cycle. If so, an increased demand for pulmonary gas exchange may enhance RSA magnitude. We therefore tested the hypothesis that CO2directly affects RSA in conscious humans even when changes in tidal volume (VT) and breathing frequency ( F B), which indirectly affect RSA, are prevented. In seven healthy subjects, we adjusted end-tidal Pco 2 (Pet CO2 ) to 30, 40, or 50 mmHg in random order at constant VT and F B. The mean amplitude of the high-frequency component of R-R interval variation was used as a quantitative assessment of RSA magnitude. RSA magnitude increased progressively with Pet CO2 ( P < 0.001). Mean R-R interval did not differ at Pet CO2 of 40 and 50 mmHg but was less at 30 mmHg ( P < 0.05). Because VT and F B were constant, these results support our hypothesis that increased CO2directly increases RSA magnitude, probably via a direct effect on medullary mechanisms generating RSA.

Force fluctuations are modulated by alternate muscle activity of knee extensor synergists during low-level sustained contraction

2004 ◽  
Vol 97 (6) ◽  
pp. 2121-2131 ◽  
Author(s):  
Motoki Kouzaki ◽  
Minoru Shinohara ◽  
Kei Masani ◽  
Tetsuo Fukunaga
Keyword(s):  
Correlation Coefficient ◽  
Muscle Activity ◽  
High Frequency ◽  
Vastus Lateralis ◽  
Frequency Component ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
High Frequency Component ◽  
Knee Extensors ◽  
Force Fluctuations

The study examined the hypothesis that altered synergistic activation of the knee extensors leads to cyclic modulation of the force fluctuations. To test this hypothesis, the force fluctuations were investigated during sustained knee extension at 2.5% of maximal voluntary contraction force for 60 min in 11 men. Surface electromyograms (EMG) were recorded from the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles. The SD of force and average EMG (AEMG) of each muscle were calculated for 30-s periods during alternate muscle activity. Power spectrum of force was calculated for the low- (≤3 Hz), middle- (4–6 Hz), and high-frequency (8–12 Hz) components. Alternate muscle activity was observed between RF and the set of VL and VM muscles. The SD of force was not constant but variable due to the alternate muscle activity. The SD was significantly greater during high RF activity compared with high VL and VM activity ( P < 0.05), and the correlation coefficient between the SD and AEMG was significantly greater in RF [0.736 (SD 0.095), P < 0.05] compared with VL and VM. Large changes were found in the high-frequency component. During high RF activity, the correlation coefficient between the SD and high-frequency component [0.832 (SD 0.087)] was significantly ( P < 0.05) greater compared with other frequency components. It is suggested that modulations in knee extension force fluctuations are caused by the unique muscle activity in RF during the alternate muscle activity, which augments the high-frequency component of the fluctuations.

scholarly journals Monomelic Atrophy

1990 ◽  
Vol 17 (2) ◽  
pp. 124-130 ◽  
Author(s):  
J. Oryema ◽  
P. Ashby ◽  
S. Spiegel
Keyword(s):  
Upper Limb ◽  
Cervical Cord ◽  
Forearm Muscles ◽  
Extensor Carpi Radialis

ABSTRACT:Weakness of distal muscles of one upper limb which progresses over 1 year and then appears to arrest (“monomelic amyotrophy”) has been reported mainly in Japan and India. We report 5 cases of a similar syndrome occurring in Canada. In our cases the wasting affected the forearm muscles of one upper limb (sparing brachioradialis and extensor carpi radialis). There was minimal wasting and electromyographic changes in the opposite upper limb. The CT myelogram showed unilateral wasting of the cervical cord.

Vagal modulation of the heart and central hemodynamics during handgrip exercise

2000 ◽  
Vol 278 (5) ◽  
pp. H1648-H1652 ◽  
Author(s):  
Heidi A. Kluess ◽  
Robert H. Wood ◽  
Michael A. Welsch
Keyword(s):  
Coefficient Of Variation ◽  
Spontaneous Breathing ◽  
Repeated Measures ◽  
Voluntary Contraction ◽  
Dependent Manner ◽  
Handgrip Exercise ◽  
Low Intensity ◽  
Vagal Modulation ◽  
The Mean ◽  
Low Intensity Exercise

Blood pressure and continuous electrocardiogram recordings were obtained from 12 participants during spontaneous breathing (SB1), dynamic handgrip exercise at 20% (HG20) of maximal voluntary contraction (MVC), and spontaneous breathing (SB2) and dynamic handgrip exercise at 60% (HG60) of MVC. Repeated-measures ANOVAs were used to examine the effects of the exercise conditions on mean arterial pressure (MAP), on mean standard deviation (SDNN), and on the coefficient of variation of R-R intervals. The mean R-R interval responded to exercise in an intensity-dependent manner. SDNN decreased with exercise but was not intensity dependent. Coefficient of variation decreased during HG20, and MAP increased following HG60. These data are consistent with the notion that changes in cardiovascular function with low-intensity exercise are primarily mediated by parasympathetic withdrawal, and as exercise intensity increases, additional cardiovascular reactivity is mediated by increased sympathetic outflow. The change in the coefficient of variation from rest to exercise was unique in comparison to the changes in SDNN, and this merits further investigation.

scholarly journals Quantifying Topographical Changes in Muscle Activation: A Statistical Parametric Mapping Approach

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 71
Author(s):  
Patricio A. Pincheira ◽  
Eduardo Martinez-Valdes ◽  
Carlos De la Fuente ◽  
Felipe Palma ◽  
Oscar Valencia ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Muscle Activation ◽  
Plantar Flexion ◽  
Statistical Parametric Mapping ◽  
High Sensitivity ◽  
Voluntary Contraction ◽  
Medial Gastrocnemius ◽  
Isometric Contractions ◽  
Parametric Mapping ◽  
Repeated Measures Anova

Regional changes in muscle activation occur at different contraction intensities. These changes can be observed with activity maps created with high-density electromyography (HDEMG). When quantifying these changes, statistical parametric mapping (SPM) is a neuroimaging technique that may be used to perform statistical analyses with high sensitivity and spatial resolution. The aim of this study was to identify regional changes in muscle activation at different contraction intensities, comparing SPM and the HDEMG barycenter (centroid). Twelve participants performed plantar flexion isometric contractions at 20%, 40%, and 60% of the maximal voluntary contraction (MVC), while HDEMG was recorded from the medial gastrocnemius. An SPM repeated measures ANOVA design revealed specific mediolateral and cephalocaudal changes in muscle activation with increasing contraction intensities, which were not clearly detected by the variation in the barycenter coordinates. Only SPM revealed statistically significant nonuniform changes in EMG amplitude between all increasing levels of muscle activation.

Extensor carpi radialis brevis origin, nerve supply and its role in lateral epicondylitis

2009 ◽  
Vol 32 (3) ◽  
pp. 207-211 ◽  
Author(s):  
Soubhagya R. Nayak ◽  
Lakshmi Ramanathan ◽  
Ashwin Krishnamurthy ◽  
Latha V. Prabhu ◽  
Sampath Madhyastha ◽  
...  
Keyword(s):  
Lateral Epicondylitis ◽  
Nerve Supply ◽  
Extensor Carpi Radialis

scholarly journals Heterotopic Ossification After the Arthroscopic Treatment of Lateral Epicondylitis

Hand ◽  
2017 ◽  
Vol 12 (3) ◽  
pp. NP32-NP36 ◽  
Author(s):  
Mihir J. Desai ◽  
Hari Ramalingam ◽  
David S. Ruch
Keyword(s):  
Heterotopic Ossification ◽  
Young Athlete ◽  
Lateral Epicondylitis ◽  
Primary Prophylaxis ◽  
Arthroscopic Treatment ◽  
Arthroscopic Debridement ◽  
Elbow Arthroscopy ◽  
First Case ◽  
Extensor Carpi Radialis ◽  
Final Disposition

Background: Heterotopic ossification (HO) is a well-known complication following the surgical treatment of fractures and dislocations about the elbow but it is not commonly discussed as a complication following arthroscopy. We present a case of a young athlete who developed HO after the arthroscopic treatment of lateral epicondylitis. Methods: This is a case report chart review of a 24 year old male with lateral epicondylitis. After failing conservative measures, arthroscopic debridement of the extensor carpi radialis brevis (ECRB) origin ensued. The treatment and patient’s final disposition were reported. Results: The patient developed heterotopic ossification of the elbow follow arthroscopic debridement of the ECRB origin. Further surgery was required to excise the heterotopic ossification. Good recovery of motion was achieved. Conclusion: To our knowledge, we present the first case of HO development after elbow arthroscopy for lateral epicondylitis. As the use of elbow arthroscopy continues to grow, there is a need for identification of the risk factors and primary prophylaxis for HO.

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