scholarly journals Validation of a Low-Cost Electromyography (EMG) System via a Commercial and Accurate EMG Device: Pilot Study

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5214 ◽  
Author(s):  
Sergio Fuentes del Toro ◽  
Yuyang Wei ◽  
Ester Olmeda ◽  
Lei Ren ◽  
Wei Guowu ◽  
...  
Keyword(s):  
Pilot Study ◽  
Linear Correlation ◽  
Low Cost ◽  
Rectus Femoris ◽  
Research Areas ◽  
Cost System ◽  
Wide Range ◽  
Spearman’S Correlation ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle

Electromyography (EMG) devices are well-suited for measuring the behaviour of muscles during an exercise or a task, and are widely used in many different research areas. Their disadvantage is that commercial systems are expensive. We designed a low-cost EMG system with enough accuracy and reliability to be used in a wide range of possible ways. The present article focuses on the validation of the low-cost system we designed, which is compared with a commercially available, accurate device. The evaluation was done by means of a set of experiments, in which volunteers performed isometric and dynamic exercises while EMG signals from the rectus femoris muscle were registered by both the proposed low-cost system and a commercial system simultaneously. Analysis and assessment of three indicators to estimate the similarity between both signals were developed. These indicated a very good result, with spearman’s correlation averaging above 0.60, the energy ratio close to the 80% and the linear correlation coefficient approximating 100%. The agreement between both systems (custom and commercial) is excellent, although there are also some limitations, such as the delay of the signal (<1 s) and noise due to the hardware and assembly in the proposed system.

scholarly journals Electromyographic Analysis of Traditional and Nontraditional Abdominal Exercises: Implications for Rehabilitation and Training

2006 ◽  
Vol 86 (5) ◽  
pp. 656-671 ◽  
Author(s):  
Rafael F Escamilla ◽  
Eric Babb ◽  
Ryan DeWitt ◽  
Patrick Jew ◽  
Peter Kelleher ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Rectus Femoris ◽  
Rectus Abdominis ◽  
Oblique Muscle ◽  
Emg Activity ◽  
Internal Oblique ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle ◽  
Roll Out

Abstract Background and Purpose. Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent-knee sit-up. The purpose of this study was to test the effectiveness of traditional and nontraditional abdominal exercises in activating abdominal and extraneous musculature. Subjects. Twenty-one men and women who were healthy and between 23 and 43 years of age were recruited for this study. Methods. Surface electromyography (EMG) was used to assess muscle activity from the upper and lower rectus abdominis, external and internal oblique, rectus femoris, latissimus dorsi, and lumbar paraspinal muscles while each exercise was performed. The EMG data were normalized to maximum voluntary muscle contractions. Differences in muscle activity were assessed by a 1-way, repeated-measures analysis of variance. Results. Upper and lower rectus abdominis, internal oblique, and latissimus dorsi muscle EMG activity were highest for the Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees. External oblique muscle EMG activity was highest for the Power Wheel (pike, knee-up, and roll-out) and hanging knee-up with straps. Rectus femoris muscle EMG activity was highest for the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up. Lumbar paraspinal muscle EMG activity was low and similar among exercises. Discussion and Conclusion. The Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees not only were the most effective exercises in activating abdominal musculature but also were the most effective in activating extraneous musculature. The relatively high rectus femoris muscle activity obtained with the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up may be problematic for some people with low back problems.

Ultrasonographic Morphologic Changes of the Central Aponeurosis of the Rectus Femoris Muscle in Individuals With Knee Osteoarthritis

2016 ◽  
Vol 32 (3) ◽  
pp. 241-246
Author(s):  
Yusuke Takahashi ◽  
Kyoji Okada ◽  
Akira Saito ◽  
Isao Saito ◽  
Kazuo Kinoshita ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Rectus Femoris ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle ◽  
Morphologic Changes

scholarly journals Reliability Limits Of The Modified Thomas Test For Assessing Rectus Femoris Muscle Flexibility About The Knee Joint

2008 ◽  
Vol 43 (5) ◽  
pp. 470-476 ◽  
Author(s):  
Jason D. Peeler ◽  
Judy E. Anderson
Keyword(s):  
Knee Joint ◽  
Intraclass Correlation ◽  
Rectus Femoris ◽  
Scoring Systems ◽  
Nonparametric Tests ◽  
Method Error ◽  
Statistical Reliability ◽  
Active Population ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle

Abstract Context: The modified Thomas test is commonly used in the clinical setting to assess flexibility about the thigh region. Objective: To evaluate the clinical reliability of the modified Thomas test for evaluating the flexibility of the rectus femoris muscle about the knee joint. Design: Descriptive laboratory study using a test-retest design. Setting: Institution-based clinical orthopaedic setting. Patients Or Other Participants: Fifty-seven individuals between the ages of 18 and 45 years with no history of trauma participated. Of those, 54 completed the study. Intervention(s): Three Board-certified athletic therapists with an average of 12.67 years of sport medicine expertise assessed rectus femoris flexibility using pass/fail and goniometer scoring systems. A retest session was completed 7 to 10 days later. Main Outcome Measure(s): Parametric and nonparametric tests were used to compare participants' test-retest results. Results: Chance-corrected κ values (intrarater x¯  =  0.40, 95% confidence interval [CI]  =  0.30, 0.54; interrater x¯  =  0.33, 95% CI  =  0.23, 0.41) indicated generally poor levels of reliability for pass/fail scoring. Intraclass correlation coefficient (ICC) values (intrarater x¯  =  0.67, 95% CI  =  0.55, 0.76; interrater x¯  =  0.50, 95% CI  =  0.40, 0.60) indicated fair to moderate levels of reliability for goniometer data. Measurement error values (standard error of measurement  =  7°, method error  =  6°, and coefficient of variation  =  13%) and Bland-Altman plots (with 95% limits of agreement) further demonstrated the degree of intrarater variance for each examiner when conducting the test. Conclusions: These results call into question the statistical reliability of the modified Thomas test and provide clinicians with important information regarding its reliability limits when used to clinically assess flexibility of the rectus femoris muscle about the knee joint in a physically active population. More research is needed to ascertain the variables that may confound the statistical reliability of this orthopaedic technique.

Distribution of Injected Adrenaline and Noradrenaline in Plasma and Muscle of the Rat

1958 ◽  
Vol 195 (3) ◽  
pp. 663-669 ◽  
Author(s):  
Joan N. Taylor
Keyword(s):  
Body Weight ◽  
Blood Plasma ◽  
Muscle Tissue ◽  
Rectus Femoris ◽  
Rat Plasma ◽  
Small Samples ◽  
Fluorimetric Method ◽  
Rectus Femoris Muscle ◽  
Femoris Muscle

The Weil-Malherbe and Bone fluorimetric method of determining adrenaline and noradrenaline was adapted for measuring these hormones in small samples of blood plasma and muscle in the rat. The endogenous levels of adrenaline and noradrenaline, respectively, for rat plasma are 6.7 ± 0.08 and 17.7 ± 0.06 µg/l.; for the rectus femoris muscle 0.020 ± 0.002 and 0.149 ± 0.011 µg/gm tissue. Ten micrograms l-adrenaline and 20 µg d,l-noradrenaline/100 gm body weight were injected intraperitoneally, and plasma and muscle samples analyzed for these hormones at timed intervals thereafter. The injection of adrenaline effects a prompt increase in both plasma and muscle noradrenaline; a significant increase in adrenaline level was found 6 minutes after injection in the plasma, and at 60 minutes in the muscle tissue. A return to initial levels occurred at approximately 10 minutes and 90 minutes, respectively. The injection of noradrenaline resulted in an immediate increase in the plasma and muscle levels of this hormone; coincidently the adrenaline levels remained relatively unchanged.

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