PRINCIPAL INVESTIGATOR (S): G. Wyckliffe Hoffler, Stuart A. Bergman, and 



Arnauld E. Nicogossian 



EXPERIMENT TITLE/NUMBER : In-Flight Lower Limb Volume Measurement 



PROGRAM/MISSION : Apollo-Soyuz Test Project 



CLASSIFICATION : Human 



DISCIPLINE(S) : Musculoskeletal 



OBJECTIVES : To substantiate with further data, the volume decrement that 

 occurs inflight, to obtain earlier inflight volume determinations and to 

 document the time course of headward fluid shifts by frequent serial leg 

 volume measurements. 



PROTOCOL : During the period from day F-45 to day F-1, five independent 

 determinations of the left leg volume were made. Crewmembers were instructed 

 and trained in the procedure and actually conducted the F-1 measurements on 

 themselves to ensure adequate familiarization for their seven inflight 

 measurement sessions. Right leg measurements were obtained three times before 

 flight and once on recovery day (R+0) by medical team personnel. Because of 

 circumstances associated with the toxic nitrogen tetroxide gas event during 

 the recovery period, leg volumes were not obtained beyond the fourth 

 postf light day (R+4). 



EQUIPMENT : Limb Volume Measuring Kit. 



RESULTS : Decreasing leg size as the launch period approached is in accordance 

 with pref light findings from previous flight crews. All inflight volumes 

 dropped below the lower 95% confidence limit established by pref light volumes. 

 Earliest postf light determinations were taken between 1.5 and 2 hours after 

 splashdown. Leg volumes on all three crewmen increased well above their last 

 inflight values. Second measurements on recovery day, some 2 to 5 hours after 

 splashdown, showed even greater leg volumes in accordance with the reversing 

 effects of readaption in normal gravity. 



CONCLUSIONS : Several of the oscillatory variations observed in ASTP flight 

 crewmembers may be judged to be actual physiologic damping responses. With a 

 single datum for inference, it appeares that the major shift of fluid volume 

 from the legs does not occur in the first few hours of orbital exposure. The 

 course seems more likely to assume an exponential form with maximal rate of 

 decrement within the first 24 hours. A distinct plateau is evident by 3 to 5 

 days with little significant additional decrease occurring after the first 

 week in weightlessness. These fluid volume shifts coincide with the 

 occurrence of major crew symptomatology and the plateau with relative adaptive 

 stability. 



PUBLICATIONS : 273 



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