PRINCIPAL INVESTIGATOR (S ): William E. Thornton, G. Wyckliffe Hoffler, and 



John A. Rummel 



EXPERIMENT TITLE/NUMBER : Anthropometric Changes and Fluid Shifts 



PROGRAM/MISSION : Skylab 4 



CLASSIFICATION : Human 



DISCIPLINE(S) : Cardiovascular 



OBJECTIVES : To obtain a comprehensive and coherent picture of changes in 

 size, shape, and composition of the human body in weightlessness. 



PROTOCOL : Nine anthropometric measurements were made at various body 

 locations pref light, and postflight. A series of pref light, inflight, and 

 postflight photographs were made with the crewmen in standard anatomical 

 position. An infared sensitive color film was used to show superficial venous 

 blood distribution. Center of mass and center of gravity measurements were 

 made to indicate fluid shifts. 



EQUIPMENT : Calibrated tape jig, infared film (35 mm), camera, center-of-mass 

 measurement device. 



RESULTS : Inflight, the spinal column was flexed with loss of the 

 thoracolumbar curve but retention of cervical curvature, so that the head was 

 thrust forward. Postflight, little change was found from pref light posture. 

 There was an inflight increase in height, a loss of abdominal girth, and a 

 large and rapid fluid shift from the lower to upper body. The center of mass 

 shifted cephalad more than could be accounted for by the height increase. 

 Photographs provided evidence for increased fluid in the head and neck region. 

 The fluid shifts reversed quickly after recovery. 



CONCLUSIONS : It is hypothesized that the driving force for the fluid shift is 

 the intrinsic and unopposed lower limb elasticity that forces venous blood and 

 then other fluid cephalad. This shift may be the driving force for a number 

 of other phenomena including blood volume loss, changes in leg hemodynamics, 

 and vestibular dysfunction. 



PUBLICATIONS : 520, 521 



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