MUSCLE - Study of lower back pain in astronauts during spaceflight
Physiology: Integrative gravitational physiology
ISS 8S (Soyuz TMA-4) Dutch "Delta" Mission
C.J. Snijders (1), C.A. Richardson (2), A.L. Pool Goudzwaard (1), J.A. Hides (2)
|(1)||Dept. of Biomedical Physics and Techn.|
Medical Center Rotterdam
Erasmus MC University
P.O. Box 1738
|(2)||Dept. of Physiotherapy|
University of Queensland
St. Lucia Q4072 Queensland
|||A.L. Pool-Goudzwaard, D.L. Belavý, J.A. Hides, C.A. Richardson, C.J. Snijders, (2012), "Low back pain in microgravity - a self-limiting disease?", Journal of Applied Physiology, submitted.|
|||J.J.W.A. van Loon, F.J. Medina, H. Stenuit, E. Istasse, M. Heppener, R. Marco, (2007), "The National-ESA Soyuz missions Andromède, Marco Polo, Odissea, Cervantes, DELTA and Eneide", Microgravity Science and Technology, 19, 5-6, DOI: 10.1007/BF02919448, pp. 9-32.|
The aim of this study was to obtain data about the development of complaints during flight on a day-to-day basis. Based on the biomechanical model it was expected that a) low back pain could develop at the site of the iliolumbar ligaments (the iliac crest) and b) a situation of combined low back pain and constipation could develop.
The questionnaire started with "Did you experience pain today in the lower back?" and if the answer was "Yes", questions about type and intensity of pain were completed with the use of a visual analogue scale. We also asked if the back was painful almost all the time, what provoked the low back pain and if it was possible to relieve the pain. Final question was if change in bladder or bowel function occurred. The questionnaire was incorporated in the general mission logbook and had the following schedule:
Pre-flight: At L-10 +/- 5 baseline data were collected with the questionnaire
In-flight: Completion of the questionnaire at the end of every flight day
Post-flight: At R+10 +/- 5 data on return to gravity load were collected with the questionnaire
The Ethical Committee approval was obtained from the institutional Review Board of the University Medical Center Rotterdam. Informed consent was signed. Because the questionnaire was anonymous, the results of this single case study are presented in a global form and in consult with the cosmonaut.
Astronauts completed a questionnaire 5-10 days prior to flight, during each flight day and 5-10 days after flight. Pain intensity and location, neurological signs, provoking moments and relieving countermeasures were catalogued. LBP was mostly experienced in the central area of the lower back during spaceflight with an incidence of 70% and a mean pain level of 3 (of a maximum of 10). Pain resolved within 10 days of flight. No neurological signs were present. All astronauts with known prior LBP developed LBP in flight. These astronauts reported a significant longer duration of LBP and a different pain location. The most frequently reported countermeasure was assuming a ‘knees to chest (fetal tuck) position’ combined with stretching. Greater LBP intensity was reported in spaceflight than bed-rest (p<0.05) with a trend indicating a greater number of days of pain during spaceflight. The current study represents the first prospective study of LBP in spaceflight. The results indicate that LBP is self limiting in spaceflight and should not pose an operational risk for long-duration space missions.
During microgravity we expect a loss of tone in the postural muscle system, especially in the transverse abdominal muscles. It is shown in low back pain patients that these muscles are inhibited after a few days of pain. Inhibition of these muscles leads to loss of stability in spine and pelvis and hence to pain in ligamentous structures as the iliolumbar ligaments inserting on the iliac crest. In order to stabilise the spine and pelvis the intra-abdominal pressure can be increased and the pelvic floor muscles can have a higher level of activity. This higher level of activity can lead to constipation, as demonstrated in a population of low back pain patients.
We are aware of the fact that the results of a single case study must be interpreted with reserve, but it forms a strong base for future studies with a series of cosmonauts who stay on the ISS for several months. The results of future studies can have a large impact for countermeasures in-flight and treatment of low back pain patients on Earth.
|For a very comprehensive overview on the first six ESA missions to the ISS, please, consult the following reference document - see also document no. 2 in the list of references above:
The National - ESA Soyuz missions Andromède, Marco Polo, Odissea, Cervantes, Delta and Eneide ;
Jack J. W. A. van Loon, F. Javier Medina, Hilde Stenuit, Eric Istasse, Marc Heppener and Roberto Marco;
Microgravity Science and Technology;
Volume 19, Numbers 5-6 (2007), 9-32, DOI: 10.1007/BF02919448|
Patrik Sundblad (e-mail: firstname.lastname@example.org)