Influence of prolonged bed-rest on spectral and temporal electromyographic motor control characteristics of the superficial lumbo-pelvic musculature

Daniel L. Belavý, Joseph Kim Fai Ng, Stephen J. Wilson, Gabriele Armbrecht, Dick F. Stegeman, Jörn Rittweger, Dieter Felsenberg, Carolyn A. Richardson

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)


Little is known about the motor control of the lumbo-pelvic musculature in microgravity and its simulation (bed-rest). Analysis of spectral and temporal electromyographic variables can provide information on motor control relevant for normal function. This study examined the effect of 56-days of bed-rest with 1-year follow-up in 10 male subjects on the median frequency and the activation timing in surface electromyographic recordings from five superficial lumbo-pelvic muscles during a repetitive knee movement task. Trunk fat mass (from whole body-composition measurements) and movement accuracy as possible explanatory factors were included. Increased median frequency was observed in the lumbar erector spinae starting late in bed-rest, but this was not seen in its synergist, the thoracic erector spinae (p < .0001). These changes persisted up to 1-year after bed-rest and were independent of changes in body-composition or movement accuracy. Analysis suggested decreases of median frequency (p < .0001) in the abdominal and gluteal muscles to result from increased (p < .01) trunk fat levels during and after bed-rest. No changes in lumbo-pelvic muscle activation timing were seen. The results suggest that bed-rest particularly affects the shorter lumbar erector spinae and that the temporal sequencing of superficial lumbo-pelvic muscle activation is relatively robust.
Original languageEnglish
Pages (from-to)170-179
Number of pages10
JournalJournal of Electromyography and Kinesiology
Issue number1
Publication statusPublished - 1 Feb 2010


  • Berlin bed-rest study
  • Median frequency
  • Motor control
  • Spaceflight
  • Spine

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Biophysics
  • Clinical Neurology

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