title: A preliminary investigation of upper limb muscle activity during simulated Canadian forest harvesting operations.
abstract: OBJECTIVE
  The forest industry is a major economic sector of Canada. While mechanized machines have reduced injuries workers suffered during manual operations, these machines have also created other musculoskeletal concerns. The purpose of this study was to obtain data regarding upper limb musculoskeletal stress during typical harvesting operations using surface electromyography (EMG).
  
  
  METHODS
  Students currently training in a forest machine operations course were recruited for this study. Four operators (1 female and 3 males, mean age = 24.6 ± 13.4 years, mean height = 172.7 ± 4.6 cm, mean weight = 75.4 ± 27.4 kg) participated in this study.
  
  
  METHODS
  Surface electrodes were placed over the muscles of the upper arm and shoulder to monitor muscular activity during Harvester Simulator operation. Operators were provided specific instructions and visual feedback. Data were collected over a two hours of operation.
  
  
  RESULTS
  Preliminary data suggests that while the movements used in the simulator do not require large force, they are repetitive and constant and can result in muscle fatigue.
  
  
  CONCLUSIONS
  The EMG data indicated signs of fatigue in several muscles of the upper arms. This preliminary data suggests that while operation of these machines does not require large force contractions, the continuous and repetitive nature of the work can result in muscular fatigue. This suggests that long term operation of mobile machines may result in fatigue and future studies should examine job design.
authors.affiliation: Faculty of Kinesiology, University of New Brunswick, Fredericton, New Brunswick, Canada. ukurugan@unb.ca
authors.forename: Usha
authors.initials: U
authors.lastname: Kuruganti
authors.forename: Tiernan P
authors.initials: TP
authors.lastname: Murphy
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Dickinson
mesh_terms: D000328:Adult; D001415:Back / Q000502:physiology; D001696:Biomechanical Phenomena; D002170:Canada; D012090:Cumulative Trauma Disorders / Q000503:physiopathology / Q000517:prevention & control*; D004576:Electromyography; D005260:Female; D005542:Forearm / Q000502:physiology; D016468:Forestry; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009333:Neck / Q000502:physiology; D009784:Occupational Diseases / Q000503:physiopathology / Q000517:prevention & control*; D012782:Shoulder / Q000502:physiology; D055815:Young Adult