The ambulatory measurement of posture, thigh acceleration, and muscle tension and their relationship to heart rate

Authors

  • MARTTI T. TUOMISTO,

    1. School of Psychology, University of St. Andrews, St. Andrews, Scotland
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    • Dr. Martti T. Tuomisto is now at the Department of Clinical Physiology, Medical School, University of Tampere, Tampere, Finland.

  • DEREK W. JOHNSTON,

    Corresponding author
    1. School of Psychology, University of St. Andrews, St. Andrews, Scotland
      Address reprint requests to: Professor Derek W. Johnston, School of Psychology, University of St. Andrews, St. Andrews, Fife KY16 9JU, Scotland.
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  • THOMAS F. H. SCHMIDT

    1. Behavioral and Preventive Medicine, Department of Epidemiology and Social Medicine, Hannover Medical School, Hannover, Germany
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  • This research was supported by the Medical Research Council in the United Kingdom.

  • We thank Michael C. Doyle for helpful comments to an earlier version of this paper

Address reprint requests to: Professor Derek W. Johnston, School of Psychology, University of St. Andrews, St. Andrews, Fife KY16 9JU, Scotland.

Abstract

We compared the relative ability of continuous accelerometric, electromyographic (EMG), and hydrostatic posture measurements to diseriminate tasks involving variations in motor activity and posture and to predict heart rate (HR) variability. EMG was a more sensitive measure than accelerometry in differentiating the tasks. How-ever, accelerometry and EMG explained comparable amounts of HR variance. The hydrostatic posture was a stable measure that elearly differentiated postures and explained a significant amount of HR variance but less than accelerometry or EMG. Accelerometric and EMG measures of motor activity used either alone or in combination with the hydrostatic posture are valuable in discriminating activities and in controlling for the effects of motor activity and posture on HR during ambulatory measurement.

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