The effect of asymmetry on psychophysical lifting capacity for three lifting types

B. Han, Terrence J Stobbe, G. R. Hobbs

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The effect of asymmetry on a person's lifting capacity was investigated using the psychophysical approach. Ten male college students lifted a box from pallet height (15 cm) to conveyor height (75 cm) at a frequency of one and five lifts/min. Three types of asymmetric lifting tasks (step-turn, middle twist and twist) were studied using 90 and 180° task angles. Lifting capacity reductions for middle twist and twist at a 90° asymmetric angle were about one-half of the 30% reduction that would be calculated by the 1991 National Institute for Occupational Safety & Health (NIOSH) lifting equation. The lifting capacity reduction for step-turn at 180° was 14.9%, although that reduction cannot be calculated in the NIOSH equation. The middle twist lifting capacity was greatest among the three types at a 90° task angle. The reductions for the middle twist and step-turn were not proportional to the task angle. This is contrary to the proportional reduction in the NIOSH lifting equation. Heart rate did not increase with an increase in task angle. Based on the results of this research, a different approach to assigning the asymmetric multiplier is proposed. This approach includes a task angle (as opposed to asymmetric angle) of up to 180°.

Original languageEnglish (US)
Pages (from-to)364-379
Number of pages16
JournalErgonomics
Volume48
Issue number4
DOIs
StatePublished - Mar 2005
Externally publishedYes

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asymmetry
National Institute for Occupational Safety and Health (U.S.)
occupational safety
multiplier
Pallets
Occupational Health
human being
health
Health
Students
Heart Rate
student
Research

Keywords

  • Asymmetry
  • Lifting
  • Psychophysics

ASJC Scopus subject areas

  • Industrial and Manufacturing Engineering
  • Human Factors and Ergonomics
  • Psychology(all)
  • Applied Psychology

Cite this

The effect of asymmetry on psychophysical lifting capacity for three lifting types. / Han, B.; Stobbe, Terrence J; Hobbs, G. R.

In: Ergonomics, Vol. 48, No. 4, 03.2005, p. 364-379.

Research output: Contribution to journalArticle

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