PRINCIPAL INVESTIGATOR (S ) : William E. Thornton, and John A. Rummel 



EXPERIMENT TITLE/NUMBER : Muscular Deconditioning and its Prevention in Space 



Flight 



PROGRAM/MISSION : Skylab 2, 3, 4 



CLASSIFICATION : Human 



DISCIPLINE(S) : Musculoskeletal 



OBJECTIVES : To prevent muscular deconditioning in space. 



PROTOCOL : Atrophy of weight-bearing muscular groups was measured with a 

 constant speed dynamometer. Ten maximum effort, full-range flexions/exten- 

 sions of the arm at the elbow and of the hip and knee at 45 degrees/second 

 were recorded and evaluated for each crewman pre- and postf light. Anthropo- 

 metric measurements allowed computation of volume changes in limb segments. A 

 bicycle ergometer and an isometric exercise device were used throughout the 

 missions for exercise, as well as a simulated treadmill which provided 170 

 pounds equivalent weight. 



EQUIPMENT : Constant speed dynamometer, bicycle ergometer, isometric device, 

 treadmill (consisting of a Teflon walking surface, a harness, and elastic 

 bungees) , mini gym. 



RESULTS : The flight crew returned in good condition. Slight losses in muscle 

 function of arms or legs were measured. 



CONCLUSIONS : Muscle in space is no different from muscle on Earth. If it is 

 properly nourished and exercised at reasonable load levels, it will maintain 

 its function. Future research efforts should focus on optimum methods of 

 exercise with respect to crew time and crew acceptance, interrelationship of 

 musculoskeletal fitness with cardiovascular fitness, and design of practical, 

 efficient, total body exercises. 



PUBLICATIONS : 524, 525 



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