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Impact Factor:0.906
Source:2014 Journal Citation Reports® (Thomson Reuters, 2015)

Estimation of Lifted Weight and Produced Effort through Perception of Point-Light Display

  1. Jaeho Shim
    1. Department of Health, Human Performance, & Recreation, Baylor University, 500 Speight, PO Box 97313, Waco, TX 76798, USA
  2. Les G Carlton
    1. Department of Kinesiology, University of Illinois at Urbana-Champaign, 233 Freer Hall, Urbana, IL 61801, USA
  3. Jitae Kim
    1. Department of Physical Education, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul 120-749, Korea
  1. e-mail: joe_shim{at}baylor.edu


It has been shown that human observers can estimate the weight of a box from the observation of a point-light display of a lifting motion. We asked observers to report the weight of the box and the effort produced by five lifters ranging in size and strength to determine if observers can perceive lifter size. In experiment 1, five or six weights from each of five lifters were shown to fourteen observers in a random order. Observers showed less error in estimating the amount of effort each lifter produced than in estimating the actual weight of the box. In experiment 2, the lifters were presented individually to forty observers to remove any effect observing a previous lift might have had on estimating the subsequent lift by a different lifter. The results showed an improvement in estimated weight but not in estimated effort. In experiment 3, the actual size of the lifters was given to thirty-four observers, and the estimations of both weight and effort improved. In experiment 4, observers did not improve when observing practice trials and estimating either only weight or only effort. The results from the four experiments suggest that observers are more sensitive to lifter's effort than to the weight lifted, and that observers tend to use changes in the velocity profile of the lift when making their estimates.

  • Received August 5, 2002.
  • Revision received July 3, 2003.
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