ABSTRACT
Repetitive movement is commonly seen in dailylife activities, for instance in sport particularly widely seen in the occupational task, such as existence in the production line of industrial sector, where workers have to perform their work tasks repetitively roughly 8 hrs a day, 5-6 days a week and for many years during their employment. Repetitive movement over such a long period of time can result in muscle fatigue, that is a consequence from a chain of metabolic, structural and energetic change in muscle, due to the insufficient oxygen and nutritive substance supplied through blood circulation, as well as a result of change in the nervous system efficiency (Cifrek et al., 2009). Most of the studies investigating muscle fatigue/ muscle activity have been limited to either isometric contractions of increasing force or sustained isometric contractions (A and K, 2006, Bu et al., 2000). That is not functional in most of the applied fields, such as occupational health and safety, sport etc. The main obstacles of this limitation consist of, firstly due to the artifacts generated from the movement and vibration on the fixed dry interelectrode closely located over the skin of subject during the dynamic contraction. Secondly due to the non-uniformity of motor unit distribution that changes rapidly over time of repetitive movement,
2 METHODS
2.1 Search strategy
The literature searches were conducted on August 28, 2014, August 31, 2014, September 1, 2014 and September 5, 2014. The searches were performed over 35 electronic databases through the search method of integrated and metasearch. The database type was E-journals. The key search terms were focused on words including “Multi-channel surface EMG”, “High-density surface EMG”, “Muscle fatigue”, “Repetitive movement”, “Ergonomics”, “Prolonged work”, “Dynamic tasks” and were used in all the database with the appropriate Boolean operators (such as And and Or). In addition other literature searches were also performed through google search engine and reference list of those relevant articles. Only full papers were considered and insufficient information formats, such as abstracts published in term of conference or workshop proceedings were not included.
