Low Back XXXX in Microgravity and Bed Rest Studies.

@entity1643 @entity158
BACKGROUND: The prevalence of @entity1643 ( @entity1643 ) for astronauts in space (68%) is higher than the 1-mo prevalence for the general population on Earth (39%). It is unclear whether differences occur between healthy subjects and astronauts with a history of @entity1643 . Knowledge of this issue is important to assess whether a history of @entity1643 could have an operational impact. METHODS: We evaluated @entity1643 prospectively during short duration spaceflight (15 d; N = 20) and compared this with similar data collected during two bed rest studies (N = 40). Astronauts completed a questionnaire 5-10 d preflight, during each flight day, and 5-10 d postflight. RESULTS: All astronauts with a history of @entity1643 also developed @entity1643 in flight. These astronauts reported a significantly longer duration of @entity1643 and a different @entity158 location. @entity1643 was most often experienced in the central area of the lower back during spaceflight with an incidence of 70% and a mean @entity158 level of 3 (on a scale of 0-10). @entity158 resolved within 10 d of flight. No neurological signs were present. The most frequently reported countermeasure was assuming a "knees to chest (fetal tuck) position" combined with stretching. Greater @entity1643 intensity was reported in spaceflight than bed rest with a trend indicating a greater number of days of @entity158 during spaceflight. DISCUSSION: The current study represents a prospective study of @entity1643 in spaceflight. The results indicate that @entity1643 is self-limiting in spaceflight and should not pose an operational risk. Prior @entity1643 on Earth appears to be a risk factor for @entity1643 in spaceflight. Pool-Goudzwaard AL, Belav   DL, Hides JA, Richardson CA, Snijders CJ. @entity1643 in microgravity and bed rest studies. Aerosp Med Hum Perform. 2015; 86(6):541-547.
