title: Manual materials handling in simulated motion environments.
abstract: Seafaring occupations have been shown to place operators at an increased risk for injury. The purpose of this study was to understand better the demands of a moving environment on the ability of a person to perform specific lifting tasks. Subjects lifted a 15-kg load under four different lifting conditions. A 6-degree-of-freedom ship motion simulator imposed repeatable deck motions under foot while subjects executed the lifting tasks. Subjects were oriented in three different positions on the simulator floor to inflict different motion profiles. Electromyographic records of four muscles were collected bilaterally, and thoracolumbar kinematics were measured. A repeated-measures ANOVA was employed to assess trunk motions and muscle activities across lifting and motion conditions. The erector spinae muscles showed a trend toward significant differences for motion effects. Maximal sagittal velocities were significantly smaller for all motion states in comparison with the stable condition (p <or= .01), whereas maximum twisting and lateral bending velocities were higher (p <or= .05). Results suggest working in a moving environment will likely increase the operator's risk for overexertion injuries, particularly to the trunk region.
authors.affiliation: Occupational Biomechanics Laboratory, McMaster University, Hamilton, ON, Canada.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Holmes
authors.forename: Scott N
authors.initials: SN
authors.lastname: MacKinnon
authors.forename: Julie
authors.initials: J
authors.lastname: Matthews
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Albert
authors.forename: Steven
authors.initials: S
authors.lastname: Mills
mesh_terms: D000328:Adult; D004576:Electromyography; D006801:Humans; D017770:Lifting; D008297:Male; D009068:Movement / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D013131:Spine / Q000502:physiology*; D013647:Task Performance and Analysis