Engineering topics

Whittle, M. W.

Publications and source records attributed to Whittle, M. W..

8 records

NASA NTRS1979

Caloric and exercise requirements of space flight - Biostereometric results from Skylab

The biostereometric study of the Skylab astronauts used stereophotogrammetry to make accurate three-dimensional measurements of body form, from which regional and total body volumes were derived. Volume changes in the thighs and calves, over the course of the flight, showed a high correlation with inflight exercise on the bicycle ergometer, and suggested that an exercise level of 80-100 W-min/d/kg lean body mass would be necessary to prevent inflight muscle atrophy. The bicycle ergometer is thus a relatively inefficient means of preventing leg muscle atrophy. Inflight caloric intake showed a high correlation with the change in volume of the buttocks, the abdomen, and the body as a whole, and suggested that a caloric intake of 47-51 kcal/d/kg lean body mass would be necessary to prevent a change in body fat. Only one of the astronauts exceeded this range and gained body fat; the group as a whole showed a mean fat loss of 1.2 kg.

Whittle, M. W.↗

NASA NTRS1977

The effects of prolonged spaceflight on the regional distribution of fluid, muscle and fat: Biostereometric results from Skylab

Biostereometric analysis of body form was performed several times preflight and postflight on the astronauts of all three skylab flights. The analysis was made by deriving the three-dimensional coordinates of numerous points on the body surface from stereoscopic pairs of photographs of the subject, using a stereoplotter. The volume of segments of the body, and of the body as a whole, was calculated by integration of cross sectional areas derived from the coordinate data. All nine astronauts demonstrated regional changes in volume distribution which could be related to changes in total body water, muscle mass, and fat deposits. The change in water resulted from a redistribution of fluid in response to zero gravity. Changes in muscle mass resulted from an alternation in patterns of musclar activity in the absence of gravity, and changes in fat resulted from discrepancies between the individual's caloric needs and his food consumption.

Whittle, M. W.↗

NASA NTRS1977

Mineral and nitrogen metabolic studies, experiment M071

The similarity between bed rest test and space flight effects on human mineral and nitrogen metabolisms indicates impairment of capable musculoskeletal functions. A pattern of urinary calcium increases and total calcium shifts suggests that calcium losses continue with time. Significant losses of nitrogen and phosphorus are associated with reduction in muscle tissue. It is concluded that capable musculoskeletal function is likely to be impaired during space flights of 1 1/2 to 3 years duration.

Whedon, G. D.↗

NASA NTRS1977

Bone mineral measurement: Experiment M078

Gamma ray absorptiometric measurements on bone mineral content, in addition to calcium balance studies, were performed on male volunteers during bed rest periods of 24 to 36 weeks duration and compared to Skylab mission data. Results show that mineral losses occur from the bones of the lower extremities during missions of up to 84 days and that in general they follow the loss patterns of the bed rest situation. The level of loss observed in Spacelab crews are not of clinical concern.

Smith, M. C., Jr.↗

NASA NTRS1977

Biostereometric analysis of body form

Four-camera stereophotogrammetry of Skylab crewmen, preflight and postflight, revealed a loss of volume of one to one and one-half liters from the legs, much of which was replaced during the first 4 postflight days. It is estimated that about one third of the loss represents partial atrophy due to relative disuse in zero-gravity, the remainder being due to a deficit in body fluid. Reduction in volume of the abdomen has also been noted.

Whittle, M. W.↗

NASA NTRS1976

Mineral and nitrogen balance study observations - The second manned Skylab mission

A metabolic study of important body elements, particularly those of the musculoskeletal system, was carried out on the astronauts of the Skylab 3 mission during the preflight, inflight, and postflight phases. An elevation in the level of urinary calcium similar to that observed in the 28-d Skylab flight continued throughout the flight. Significant nitrogen and phosphorus losses, apparently associated with muscle tissue loss, occurred in spite of inflight exercise programs. On the basis of these results it is predicted that capable musculoskeletal function is likely to occur in flights longer than about 9 months in duration.

Whedon, G. D.↗

NASA NTRS1976

Bone mineral changes - The second manned Skylab mission

The mineral content of the central os calcis, and distal radius and ulna was measured by the monoenergetic photon absorptiometric technique pre- and postflight on the SL-3 crewmen. No significant changes were observed in the radius and ulna. Only the SPT showed a loss in calcaneal mineral which slowly returned to preflight levels by the 87th postflight day.

Vogel, J. M.↗

NASA NTRS1976

Biostereometric analysis of body form - The second manned Skylab mission

Results of biostereometric analyses of the body form of the Skylab 3 crew before and after flight. The Cartesian coordinates of numerous points on the body surface were derived by stereophotogrammetry, and mathematical analysis of the coordinate description allowed computation of the surface area and volume of the body, the volume of body segments, and the area and shape of cross sections. The weight loss in all three crew members was accompanied by a loss in volume distributed between the trunk and legs, with the legs showing the greatest proportional loss. The observed loss of volume apparently resulted from a combined loss of fluid in the abdomen and legs, of muscle in the legs and paraspinal region, and of fat in the abdomen and buttocks.

Whittle, M. W.↗