PRINCIPAL INVESTIGATOR (S ): John M. Vogel , Michael W. Whittle, Malcolm C. 



Smith, and Paul C. Rambaut 



EXPERIMENT TITLE/NUMBER : Bone Mineral Measurement, M078 



PROGRAM/MISSION : Skylab 2, 3, 4 



CLASSIFICATION : Human 



DISCIPLINE(S) : Musculoskeletal 



OBJECTIVES : To assess the effects of the spaceflight environment on the 

 occurrence and degree of bone mineral changes. 



PROTOCOL : The photon absorptiometric technique was used to determine bone 

 mineral content in the central left .os calcis and the right distal radius ..and 

 ulna. An essentially monoenergetic photon source, the 27.5 KeV X-ray of "I, 

 and a sodium iodide crystal scintillation detector were used. They were 

 mounted on a scanner yoke which scanned the limb placed between the source and 

 detector. 



EQUIPMENT : A scanning apparatus, gamma ray detector, multichannel analyzer. 



RESULTS : No significant mineral losses were observed in any of the Skylab 2 

 crew. Only the Scientist Pilot of Skylab 3 and 4, and the Pilot of Skylab 4 

 had significant mineral losses in the .os calcis . No losses in the radius and 

 ulna were seen. The losses observed generally followed the loss pattern 

 observed in a heterogeneous group of bedrest subjects. 



CONCLUSIONS : Mineral losses from the bones of the lower extremities occurred 

 during missions of up to 84 days and they followed the loss patterns of 

 bedrest situations. The levels of loss observed in the Skylab crews were of 

 no clinical concern. 



PUBLICATIONS : 485, 536, 537, 538, 539 



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