Abstract
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 language | English |
---|---|
Pages (from-to) | 170-179 |
Number of pages | 10 |
Journal | Journal of Electromyography and Kinesiology |
Volume | 20 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Feb 2010 |
Keywords
- Berlin bed-rest study
- Median frequency
- Motor control
- Spaceflight
- Spine
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Biophysics
- Clinical Neurology