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Accurate work-rate measurements during in vivo MRS studies of exercising human quadriceps
- Source :
- Magnetic Resonance Materials in Physics, Biology and Medicine, Magnetic Resonance Materials in Physics, Biology and Medicine, Springer Verlag, 2008, 21 (3), pp.227-235, Magnetic Resonance Materials in Physics, Biology and Medicine, 2008, 21 (3), pp.227-235
- Publication Year :
- 2008
- Publisher :
- HAL CCSD, 2008.
-
Abstract
- Given that we have reached a point in the field of muscle energetics where absolute measurements are warranted to take the area forward, we designed an ergometer, including two force and two displacement transducers, allowing dynamic and isometric knee extension within a MR system and accurate measurements of power output.On the basis of repeated measurements, the force and displacement transducers accuracy was 1% for values ranging from 0 to 394 N and 4% for values ranging from 0 to 20 cm. In addition, measurements were not affected by magnetic field. MRS experiments in exercising muscle were conducted in eight subjects. They performed two standardized dynamic alternate leg extension exercises (25 and 35% of MVC) while the corresponding metabolic changes were measured using (31)P-MRS.The mean power output produced during both exercises were 63 +/- 16 and 81 +/- 15 W while the eccentric work was reduced i.e. 12 +/- 14 and 21 +/- 6 W for the moderate and heavy exercise respectively. The corresponding metabolic changes were significant with a 20-40% PCr depletion and an end of exercise pH ranging from 0.02 to 0.70 pH units.Overall, the present ergometer allows quadriceps exercise in a MR system and should be useful for future metabolic studies for which reliable and absolute quantification of power output is warranted.
- Subjects :
- [SPI.OTHER]Engineering Sciences [physics]/Other
0303 health sciences
Magnetic Resonance Spectroscopy
Ergometry
Radiological and Ultrasound Technology
Computer science
[SPI.OTHER] Engineering Sciences [physics]/Other
030310 physiology
Biophysics
Isometric exercise
Work rate
Knee extension
Displacement (vector)
Quadriceps Muscle
03 medical and health sciences
0302 clinical medicine
Absolute measurement
Humans
Radiology, Nuclear Medicine and imaging
Power output
Exercise
030217 neurology & neurosurgery
Simulation
ComputingMilieux_MISCELLANEOUS
Subjects
Details
- Language :
- English
- ISSN :
- 09685243 and 13528661
- Database :
- OpenAIRE
- Journal :
- Magnetic Resonance Materials in Physics, Biology and Medicine, Magnetic Resonance Materials in Physics, Biology and Medicine, Springer Verlag, 2008, 21 (3), pp.227-235, Magnetic Resonance Materials in Physics, Biology and Medicine, 2008, 21 (3), pp.227-235
- Accession number :
- edsair.doi.dedup.....8007bfa5b9d042b525b2a7011f28f1f0