Evaluation of the effectiveness of muscle assistive device using muscle fatigue analysis

2013 ◽  
Author(s):  
Youngjin Lee ◽  
Youngjoon Chee
Keyword(s):  
Muscle Fatigue ◽  
Fatigue Analysis ◽  
Assistive Device

Muscle Fatigue Assessment During Cycle Ergometer Exercise Using Principal Component Analysis of Electromyogram Power Spectra

2016 ◽  
Vol 32 (6) ◽  
pp. 593-598 ◽  
Author(s):  
Igor Ramathur Telles Jesus ◽  
Roger Gomes Tavares Mello ◽  
Jurandir Nadal
Keyword(s):  
Principal Component Analysis ◽  
Muscle Fatigue ◽  
Vastus Lateralis ◽  
Power Spectra ◽  
Principal Component ◽  
Component Analysis ◽  
Fatigue Analysis ◽  
Cycle Ergometer ◽  
Vastus Lateralis Muscle ◽  
Ergometer Exercise

During muscle fatigue analysis some standard indexes are calculated from the surface electromyogram (EMG) as root mean square value (RMS), mean (Fmean), and median power frequency (Fmedian). However, these parameters present limitations and principal component analysis (PCA) appears to be an adequate alternative. In this context, we propose two indexes based on PCA to enhance the quantitative muscle fatigue analysis during cyclical contractions. Signals of vastus lateralis muscle were collected during a maximal exercise test. Twenty-four subjects performed the test starting at 12.5 W power output with increments of 12.5 W⋅min–1, maintaining cadence of 50 rpm until voluntary exhaustion. The epochs of myoelectric activation were identified and used to estimate the power spectra. PCA was then applied to the power spectra of each subject. The standard (ST) and Euclidean (ED) distances were employed to estimate the alteration occurred due to fatigue. For comparison, the standard indexes were calculated. ST, ED, and RMS value were adequate for muscle fatigue analysis. Among these parameters, ST was more sensitive with higher effect size. Moreover, the Fmean and Fmedian were not sensitive to fatigue. The proposed method based on PCA of EMG in frequency domain allowed producing fatigue indexes suitable for cyclical contractions.

scholarly journals Development of Working Facility to Improve Work Posture at Packaging Section in Organic Vegetable Industry

2018 ◽  
Vol 4 (2) ◽  
pp. 65
Author(s):  
Herindra Adhi Nusantara ◽  
Guntarti Tatik Mulyati Suharno
Keyword(s):  
Risk Assessment ◽  
Muscle Fatigue ◽  
Upper Limb ◽  
Fatigue Analysis ◽  
Improve Working ◽  
Manual Task ◽  
Work Posture ◽  
Working Posture ◽  
Analysis System ◽  
Keywords Ergonomics

Working facilities may influence worker’s working posture. CV.Tani Organik Merapi (CV.TOM) is an organic vegetables company. The company provides ”dingklik” (footstool) for working. While working with “footstool”, workers must bend their legs with high bend degrees as well as their back. This poor working posture is caused by bad working facilities. It’s important to check the working posture to know whether the improvement of working facilities is needed or not. Ovako Working Analysis System (OWAS) was used to check the badness level of working posture in every CV.TOM’s working activities. It’s identified that packaging section has the worst working posture. Then it was decided to provide a new working facility to improve working posture in packaging section. CATIA V5 was used to design the new working facility. Three ergonomics tools were used to compare footstool” working posture with the new working facility. Those tools are Rapid Upper Limb Assessment (RULA), Manual Task Risk Assessment (ManTRA), and Rodgers Muscle Fatigue Analysis (RMFA). It was found that the new working facility can substitute “dingklik” with lower posture score and safer. Keywords: Ergonomics; Catia; Comfortability; Facility; Working posture

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