Affiliations: Faculty of Kinesiology, University of New Brunswick,
Fredericton, New Brunswick, Canada
Note: [] Address for correspondence: Usha Kuruganti, Faculty of
Kinesiology, University of New Brunswick, 2 Peter Kelley Dr., Fredericton, NB,
E3B 5A3 Canada. Tel.: +1 506 447 3101; Fax: +1 506 453 3511; E-mail:
[email protected]
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). Participants: 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.
