EMG Changes of the ECU Muscle with Exposure to Repetitive Ulnar Deviation

2002 ◽  
Vol 46 (13) ◽  
pp. 1086-1089
Author(s):  
Kirsty J. Bennie ◽  
Vincent M. Ciriello ◽  
Peter W. Johnson ◽  
Jack Tigh Dennerlein
Keyword(s):  
Repeated Measures ◽  
Early Stage ◽  
Work Conditions ◽  
Emg Activity ◽  
Median Frequency ◽  
Repetitive Work ◽  
Ulnar Deviation ◽  
Repeated Measures Design ◽  
Emg Signal ◽  
And Control

Our objective was to quantify changes in muscle EMG activity due to repetitive work. Using a repeated measures design, 13 females participated in 3 conditions, each lasting two eight-hour days: a control inactive condition, and two repetitive work conditions with ulnar deviation tasks at 20 and 25 repetitions per minute. EMG of the extensor carpi ulnaris muscle (ECU) was recorded during voluntary isometric contractions (20% and 60% MVC) eight times throughout the work and control days. The amplitude of the EMG signal was lower on workdays compared to the control days. Initial median frequency of the EMG signal showed no change between the control and workdays; however, the decline of the median frequency with respect to time over the course of each isometric contraction was steeper during workdays compared to control days. These changes suggest that the muscles are in an early stage of fatigue when working for an eight-hour workday.

Electromyographic Evaluation of Abdominal-Muscle Function With and Without Concomitant Pelvic-Floor-Muscle Contraction

2013 ◽  
Vol 22 (2) ◽  
pp. 108-114 ◽  
Author(s):  
Nahid Tahan ◽  
Amir Massoud Arab ◽  
Bita Vaseghi ◽  
Khosro Khademi
Keyword(s):  
Pelvic Floor ◽  
Muscle Contraction ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Pelvic Floor Muscle ◽  
Abdominal Muscle ◽  
Emg Activity ◽  
Abdominal Muscles ◽  
Repeated Measures Design ◽  
Emg Signal

Context:Coactivation of abdominal and pelvic-floor muscles (PFM) is an issue considered by researchers recently. Electromyography (EMG) studies have shown that the abdominal-muscle activity is a normal response to PFM activity, and increase in EMG activity of the PFM concomitant with abdominal-muscle contraction was also reported.Objective:The purpose of this study was to compare the changes in EMG activity of the deep abdominal muscles during abdominal-muscle contraction (abdominal hollowing and bracing) with and without concomitant PFM contraction in healthy and low-back-pain (LBP) subjects.Design:A 2 × 2 repeated-measures design.Setting:Laboratory.Participants:30 subjects (15 with LBP, 15 without LBP).Main Outcome Measures:Peak rectified EMG of abdominal muscles.Results:No difference in EMG of abdominal muscles with and without concomitant PFM contraction in abdominal hollowing (P = .84) and abdominal bracing (P = .53). No difference in EMG signal of abdominal muscles with and without PFM contraction between LBP and healthy subjects in both abdominal hollowing (P = .88) and abdominal bracing (P = .98) maneuvers.Conclusion:Adding PFM contraction had no significant effect on abdominal-muscle contraction in subjects with and without LBP.

Cryotherapy Does Not Affect Peroneal Reaction Following Sudden Inversion

2007 ◽  
Vol 16 (4) ◽  
pp. 285-294 ◽  
Author(s):  
Christine L. Berg ◽  
Joseph M. Hart ◽  
Riann Palmieri-Smith ◽  
Kevin M. Cross ◽  
Christopher D. Ingersoll
Keyword(s):  
Ankle Joint ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Treatment Time ◽  
Post Treatment ◽  
Emg Activity ◽  
Root Mean Square Amplitude ◽  
Lateral Ankle ◽  
Repeated Measures Design ◽  
And Control

Context:If ankle joint cryotherapy impairs the ability of the ankle musculature to counteract potentially injurious forces, the ankle is left vulnerable to injury.Objective:To compare peroneal reaction to sudden inversion following ankle joint cryotherapy.Design:Repeated measures design with independent variables, treatment (cryotherapy and control), and time (baseline, immediately post treatment, 15 minutes post treatment, and 30 minutes post treatment).Setting:University research laboratory.Patients or Other Participants:Twenty-seven healthy volunteers.Intervention(s):An ice bag was secured to the lateral ankle joint for 20 minutes.Main Outcome Measures:The onset and average root mean square amplitude of EMG activity in the peroneal muscles was calculated following the release of a trap door mechanism causing inversion.Results:There was no statistically significant change from baseline for peroneal reaction time or average peroneal muscle activity at any post treatment time.Conclusions:Cryotherapy does not affect peroneal muscle reaction following sudden inversion perturbation.

scholarly journals Effects of Sampling Frequency and Sample Window Size on Median Frequency of Surface EMG

2019 ◽  
Vol 63 (1) ◽  
pp. 1369-1372
Author(s):  
Pramiti Sarker ◽  
Gary Mirka
Keyword(s):  
Biceps Brachii ◽  
Window Size ◽  
Elbow Flexion ◽  
Surface Emg ◽  
Sampling Frequency ◽  
Emg Activity ◽  
Median Frequency ◽  
Surface Electrodes ◽  
Emg Signal ◽  
Sample Window

Muscle fatigue can be evaluated through the assessment of the downward shift in the median frequency (MDF) of the electromyographic (EMG) signal collected through surface electromyography. Previous research has shown that the value of MDF may be affected by sampling parameters. The purpose of this study was to quantify the combined effect of different sampling frequencies and window sizes on the calculated MDF. A sample of 24 participants performed a simple static elbow flexion exertion (15% MVC) and the EMG activity of the biceps brachii was periodically sampled using surface electrodes for four seconds at a frequency of 4096 Hz as the biceps brachii became fatigued. These collected data were then down-sampled to create a dataset of four window sizes (1s, 2s, 3s, and 4s) and five sampling frequencies (256 Hz, 512 Hz, 1024 Hz, 2048 Hz, and 4096 Hz). Median frequencies were calculated for each combination of sampling frequency and window size and then compared with the 4096 Hz / 4 s condition (considered gold standard) and the errors were calculated. Results suggest the use of a minimum sampling frequency of 512 Hz and a window size of 4s.

scholarly journals Impact Evaluation of an Addiction Intervention Program in a Quebec Prison

2015 ◽  
Vol 9 ◽  
pp. SART.S22464
Author(s):  
Catherine Arseneault ◽  
Marc Alain ◽  
Chantal Plourde ◽  
Francine Ferland ◽  
Nadine Blanchette-Martin ◽  
...  
Keyword(s):  
Substance Use ◽  
Repeated Measures ◽  
Intervention Program ◽  
Multidimensional Data ◽  
Control Group ◽  
Preliminary Results ◽  
Repeated Measures Design ◽  
Treatment Services ◽  
Quasi Experimental ◽  
And Control

Objectives This study evaluates the effects of a prison-based addiction intervention program. The evaluation is based on a multidimensional data collection that draws a portrait of the respondents’ substance use, and of their psychological/emotional, social, and judicial spheres. It measures the changes, or lack thereof, in substance use; the psychological/emotional, social, and judicial spheres; as well as the post-treatment services used. Method A quasi-experimental repeated measures design (0, 6 weeks, and 6 months) was used. Effects of the program were identified by comparing the results obtained by a group of inmates who had participated in the program ( n = 80; experimental group) with those of another group who had received no intervention ( n = 70; control group). Results The preliminary results suggested a certain treatment effect related to impulsivity and psychological distress. Conclusion Although the preliminary results were promising, the experimental and control groups did not differ significantly when more robust analyses were used.

scholarly journals La educación emocional en la infancia: una estrategia inclusiva

Aula Abierta ◽  
2017 ◽  
Vol 46 (2) ◽  
pp. 73 ◽  
Author(s):  
Amaya Cepa Serrano ◽  
Davinia Heras Sevilla ◽  
María Fernández-Hawrylak
Keyword(s):  
Inclusive Education ◽  
Repeated Measures ◽  
Educational Needs ◽  
Special Educational Needs ◽  
Five Dimensions ◽  
Repeated Measures Design ◽  
Before And After ◽  
Post Test ◽  
And Control ◽  
Emotional Education

RESUMENEsta investigación está enmarcada dentro del ámbito de la Educación Emocional en edades tempranas. El objetivo de este estudio es comprobar la eficacia del Programa EMO-ACCIÓN de educación emocional, valorando su impacto en niños de 4 a 5 años con necesidades específicas de apoyo educativo. Para este trabajo se ha seleccionado un grupo de 22 alumnos/as de Educación Infantil con estas necesidades, de una muestra de 123 alumnos/as matriculados en un colegio ordinario preferente en limitaciones físicas. Se utiliza un diseño de medidas repetidas pre-test/post-test con grupos experimental (12 alumnos) y control (10 alumnos). Para ello, se administra antes y después de la intervención educativa la escala RRER para la medición de competencias emocionales. Los resultados muestran que los alumnos que participaron en el programa educativo incrementan de forma significativa sus competencias emocionales, encontrándose una clara mejora en las cinco dimensiones que se evalúan en la escala. El programa favorece el desarrollo de las competencias emocionales, tanto para alumnado que presenta o no dificultades educativas.Palabras Clave: competencias emocionales, educación infantil, alumnado con necesidades específicas de apoyo educativo, educación inclusiva, educación emocional.ABSTRACTThis research is framed within the emotional education at early childhood. The aim of this study is to test the efficiency of the EMO-ACCIÓN Program of emotional education, assessing its impact in 4-5 years old children with special educational needs. We selected 22 children within a sample of 123 schooled in a preferred ordinary center in physical limitations. A repeated measures design pretest/posttest was used, with experimental (12 children) and control (10 children) groups. In order to measure the emotional competences, the Recognition, Regulation, Empathy and Problem Solving Scale (RRER) was administered before and after the educational intervention. The outcomes show that the children who participated in the educational program increase their emotional competences significantly, with a clear improvement in the five dimensions that the scale evaluate. The program stimulates the development of emotional competences, both in the children with or without educational needs.Keywords: emotional competences, child education, students with special, educational needs, inclusive education, emotional education.

Evaluation of Microsoft's Comfort Curve Keyboard

2005 ◽  
Vol 49 (14) ◽  
pp. 1359-1363 ◽  
Author(s):  
Hugh McLoone ◽  
Chau Hegg ◽  
Peter W. Johnson
Keyword(s):  
Repeated Measures ◽  
Wrist Extension ◽  
Ulnar Deviation ◽  
Repeated Measures Design ◽  
Design Goal ◽  
Subjective Discomfort ◽  
Speed And Accuracy ◽  
Postural Performance

The purpose of this study was to determine whether there were any postural, performance or perceived comfort differences between a conventional straight keyboard and a new ergonomic concept keyboard developed by Microsoft called the Comfort Curve. The concept keyboard was designed to promote more neutral postures in the wrist using a built-in, padded wrist rest to reduce wrist extension and curved keys in alphanumeric section of the keyboard to reduce ulnar deviation. Using a repeated measures design, 26 typists from various occupations randomly used each keyboard for a period of 15 minutes. Wrist postures were measured using electrogoniometers, typing speed and accuracy was measured using typing performance software and discomfort was subjectively measured in the hands, forearms and shoulders and neck. Compared to the conventional straight keyboard, the Comfort Curve keyboard reduced ulnar deviation by 2.2 ° (p < 0.01) and wrist extension by 6.5 ° (p <0.01). There was a small differences in typing speed (50.6 vs 51.8 WPM; p = 0.03) but no differences in accuracy (93.1% vs. 93.5%, p = 0.29) between the Comfort Curve and standard keyboards respectively. Subjective discomfort ratings in all measured body locations were lower with the Comfort Curve keyboard. The results indicate that the concept keyboard achieved its design goal of reducing wrist extension, ulnar deviation and discomfort while not compromising typing speed and accuracy.

scholarly journals An Intervention to Improve Motivation for Homework

2013 ◽  
Vol 23 (1) ◽  
pp. 34-48 ◽  
Author(s):  
Elisabeth Akioka ◽  
Linda Gilmore
Keyword(s):  
Repeated Measures ◽  
Student Attitudes ◽  
Male Students ◽  
Sources Of Information ◽  
Multiple Sources ◽  
Intervention Effect ◽  
Repeated Measures Design ◽  
Single Sex ◽  
And Control

A repeated measures design, with randomly assigned intervention and control groups and multiple sources of information on each participant, was used to examine whether changing the method of delivery of a school's homework program in order to better meet the students’ needs for autonomy, relatedness and competence would lead to more positive student attitudes to homework, and whether there would also be a positive change in overall motivation. The participants were 104 male students aged 10 to 12 years who attended a single sex high school. There was no overall intervention effect on motivation; however, the intervention appeared to have a protective effect on the quality of motivation.

Effect of Humeral-Elevation Angle on Electromyographic Activity in the Serratus Anterior During the Push-Up-Plus Exercise

2017 ◽  
Vol 26 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Ui-jae Hwang ◽  
Oh-yun Kwon ◽  
In-cheol Jeon ◽  
Si-hyun Kim ◽  
Jong-hyuck Weon
Keyword(s):  
Outcome Measures ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Elevation Angle ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Repeated Measures Design ◽  
Activity Ratios ◽  
Push Up

Context:The push-up-plus (PP) exercise has been recommended for strengthening of the serratus anterior (SA). Previous studies have investigated the effect of different stability properties of the base of support to adjust the difficulty level of SA muscle-strengthening exercises in the PP position. However, the optimal humeral-elevation angle (HEA) for selective activation and maximum contraction of the SA during PP has not been investigated.Objectives:To assess the effects of HEA during PP on electromyographic (EMG) activity in the SA, upper trapezius (UT), and pectoralis major (PM) and on the UT:SA and PM:SA activity ratios.Design:Comparative, repeated-measures design.Setting:University research laboratory.Participants:29 healthy men.Main Outcome Measures:The subjects performed PP at 3 different HEAs (60°, 90°, and 120°); EMG activity in the SA, UT, and PM was measured, and the UT:SA and PM:SA activity ratios were calculated. Differences in muscle activity and ratios between the 60°, 90°, and 120° HEAs were assessed using 1-way repeated-measures analysis of variance; the Bonferroni correction was applied.Results:SA muscle activity was significantly increased, in order of magnitude, at the 120°, 90°, and 60° HEAs. UT:SA and PM:SA activity ratios were significantly greater during performance of the PP at an HEA of 60° than at HEAs of 120° and 90°.Conclusion:The results suggest that an HEA of 120° should be used during performance of the PP because it produces greater SA activation than HEAs of 60° and 90°.

scholarly journals A Biomechanical Investigation of A Single-Limb Squat: Implications for Lower Extremity Rehabilitation Exercise

2008 ◽  
Vol 43 (5) ◽  
pp. 477-482 ◽  
Author(s):  
Jim Richards ◽  
Dominic Thewlis ◽  
James Selfe ◽  
Andrew Cunningham ◽  
Colin Hayes
Keyword(s):  
Repeated Measures ◽  
Knee Flexion ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Knee Extensors ◽  
Emg Activity ◽  
Repeated Measures Design ◽  
Biomechanical Investigation ◽  
Rehabilitative Intervention ◽  
Integrated Emg

Abstract Context: Single-limb squats on a decline angle have been suggested as a rehabilitative intervention to target the knee extensors. Investigators, however, have presented very little empirical research in which they have documented the biomechanics of these exercises or have determined the optimum angle of decline used. Objective: To determine the involvement of the gastrocnemius and rectus femoris muscles and the external ankle and knee joint moments at 60° of knee flexion while performing a single-limb squat at different decline angles. Design: Participants acted as their own controls in a repeated-measures design. Patients or Other Participants: We recruited 10 participants who had no pain, injury, or neurologic disorder. Intervention(s): Participants performed single-limb squats at different decline angles. Main Outcome Measure(s): Angle-specific knee and ankle moments were calculated at 60° of knee flexion. Angle-specific electromyography (EMG) activity was calculated at 60° of knee flexion. Integrated EMG also was calculated to determine the level of muscle activity over the entire squat. Results: An increase was seen in the knee moments (P &lt; .05) and integrated EMG in the rectus femoris (P &lt; .001) as the decline angle increased. A decrease was seen in the ankle moments as the decline angle increased (P  =  .001), but EMG activity in the gastrocnemius increased between 16° and 24° (P  =  .018). Conclusions: As the decline angle increased, the knee extensor moment and EMG activity increased. As the decline angle increased, the ankle plantar-flexor moments decreased; however, an increase in the EMG activity was seen with the 24° decline angle compared with the 16° decline angle. This indicates that decline squats at an angle greater than 16° may not reduce passive calf tension, as was suggested previously, and may provide no mechanical advantage for the knee.

scholarly journals PSIV-17 Muscular Tension as a Marker of Stress in Horses

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 285-286
Author(s):  
Ellen M Rankins ◽  
Helio C Manso ◽  
Karyn Malinowski ◽  
Kenneth H McKeever
Keyword(s):  
Social Isolation ◽  
Repeated Measures ◽  
Mixed Model ◽  
Negative Binomial ◽  
Median Frequency ◽  
Novel Object ◽  
Emg Signal ◽  
Muscular Tension ◽  
Left And Right ◽  
The Right

Abstract Effects of social isolation, sham clipping, and novel object exposure on muscular and behavioral responses were investigated in horses. Humans increase muscular tension under psychologically or physically demanding situations and thus, similar conditions were expected to alter stress responses in horses. Eight mature Standardbreds (4 mares, 4 geldings) were exposed to 3 min of social isolation (ISO), sham clipping (CLIP), novel object (NOV), and control (CON) conditions in a replicated 4×4 Latin Square experimental design with 10 min washout periods. Surface electromyography (EMG) and stress-related behaviors were recorded continuously. Median frequency (MF) and average rectified value (ARV) of the EMG signal were calculated for the first, middle, and final 10 sec of each period. EMG data were log transformed prior to analysis with a mixed model, repeated measures ANOVA. Behavior data were analyzed using a negative binomial distribution mixed model ANOVA. Significantly different means were separated using Tukey’s method. More stress-related behaviors (P &lt; 0.05) were observed during ISO (3.25 ± 0.26, LSM ± SE) than CON (1.46 ± 0.29) or CLIP (1.50 ± 0.36). ISO tended (P = 0.054) to produce more stress-related behaviors than NOV (2.31 ± 0.28). CLIP and ISO produced higher (P &lt; 0.05) ARV than CON or NOV in the left and right masseter. CLIP elicited the highest (P &lt; 0.05) MF in the left and right masseter with ISO resulting in lower (P &lt; 0.05) MF than CON. ARV was higher (P &lt; 0.05) in the left cervical trapezius during ISO as compared to all other conditions and in the right as compared to CON and CLIP. In the right cervical trapezius, ISO elicited higher (P &lt; 0.05) MF than CON. Increased stress-related behaviors indicate a stress response was induced. Elevated muscular activity suggests muscular tension can be used in assessing stress.

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