Hakan Ilaslan MD, Presenter: Nothing to Disclose

Peter Cavanagh, Abstract Co-Author: Nothing to Disclose

Kerim Genc, Abstract Co-Author: Nothing to Disclose

Raghavan Gopalakrishnan, Abstract Co-Author: Nothing to Disclose

Shamseldeen Younes Mahmoud MD, Abstract Co-Author: Nothing to Disclose

Andrea Rice, Abstract Co-Author: Nothing to Disclose

Michael Lieber, Abstract Co-Author: Nothing to Disclose

Jean Pierre Schils MD, Abstract Co-Author: Nothing to Disclose

Prolonged bedrest is a frequently used analog to study musculoskeletal changes that occur during long-duration space flight. This study was conducted to determine changes in the lumbar disc volumes before and after 12 weeks of absolute bed rest in control and exercise groups.

9 subjects, who were not habitual exercisers, were randomized to control or exercise groups and confined for 12 weeks to 6-degree head-down. During this time, the exercise group underwent individualized daily exercise programs in the Zero Gravity Locomotion Simulator (ZLS) designed to replace their daily mechanical load stimulus experienced during free-living. Control subjects were suspended in the ZLS for equivalent periods of time but did not exercise. MRI of lumbar spine was performed in sagittal plane T2W sequence (TR: 3800, TE: 104) at the start and end of bedrest performed on a Siemens 1.5 Tesla Siemens MAGNETOM scanner and the phase-array coil. Measurement of disc volumes was performed using AFNI with a semi-automated technique at L1-L2 and L2-L3 levels.

All volunteers showed an increase in the disc volumes after the bed rest, ranging from 1.2% to 19.7%. Average increase was 9.8% (exercise group) vs. 12.2% (control group). The difference in percent change between exercise and control groups is not statistically significant (in part because of the small sample size; p= 0.56, Wilcoxon rank-sum test).

All subjects had increase in the disc volumes, although less increase was observed in exercise group.

Exercise appears to partially counteracts lumbar spine disc volume increase associated with simulated microgravity.  

Ilaslan, H, Cavanagh, P, Genc, K, Gopalakrishnan, R, Mahmoud, S, Rice, A, Lieber, M, Schils, J, Exercise as a Countermeasure to Lumbar Disc Volume Changes during 12 Weeks of Simulated Microgravity.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9010846.html