This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Locomotor Exercise in Weightlessness
Annotation ability available
Sector:
Language:
English
Abstract
Human locomotion is an essential capability for normal activity on Earth. It requires the largest muscle and bone mass in the body and this muscle activity normally determines cardio-respiratory capacity. Active individuals, including the astronaut population, usually take > 104 steps day - 1 at rates of 1 - 3 steps sec - 1 with foot ground forces of 1 - 1.4 body weight (B.W.) walking and 2-3 + B W. running, producing up to 300W equivalent work. Forces and energy levels are a function of mode (walk or run), B.W, velocity, and surface grade and consistency. Overground and treadmill (T.M.) locomotion are equivalent on Earth.
In weightlessness, locomotion is impossible and, without exercise, there will be a rapid loss of muscle, bone, and cardio-respiratory capacity such that, after several months' spaceflight without exercise, most individuals will be unable to walk from strength loss. Currently, the only exerciser capable of providing locomotor activity in flight is a treadmill which must also provide a constant axial truncal force equivalent to B.W. Subject-driven treadmills can operate at a variety of controlled speeds but only at some minimum equivalent grade, and a motor-driven unit can be designed to operate over all practical speeds and equivalent grades. Both US and USSR programs have simple flight T.M.s. US T.M.s and instrumentation have been designed and prototypes demonstrated that provide performance equivalent to Earth units. Such designs, if properly utilized, should maintain locomotor and cardio-respiratory capacity during long flight at a level consistent with required postflight activities.
Authors
Topic
Citation
Thornton, W. and Whitmore, H., "Locomotor Exercise in Weightlessness," SAE Technical Paper 911457, 1991, https://doi.org/10.4271/911457.Also In
References
- Dill, D. B. Handbook of Physiology Sec. 4, Adaptation to the Environment, Am. Physiol. Soc. USA 1964
- Thornton, W. Rummel J. A. Muscular Deconditioning and Its Prevention in Space Flight Biomedical Results from Skylab 191-7 1976
- Whedon, G. W. et al. Mineral and Nitrogen Metabolic Studies Biomedical Results from Skylab 330-8 1976
- Vogel, J. M. Bone Mineral Measurement: Skylab Experiment MO 78 Biomedical Results from Skylab 1977
- Hogberg, P. Length of Stride, Stride Frequency, Flight Period and Maximum Distance Between the Feet During Running with Different Speeds Int. Z. Angew. Physiol 14 431 1952
- McArdle, W. D. Katch, F. I. Katch V. L. Exercise Physiology 1st Lea and Febinger 1981 U.S.A.
- Cavanagh, P. LaFortune, M. A. Ground Reaction Forces in Distance Running J. of Biomech. 12 5 397 406 1980
- Okumura, S. et al. Analysis of the Resultant Floor Reaction Forces in Normal Gait in Biomechanics VIIIB Proc. of Eighth Int. Congr. of Biomech. Human Kinetics Publishers 1198 1204
- Lanshammar, H. Strandberg, L. Horizontal Floor Reaction Forces and Heel Movements During the Initial Stance Phase Proc. of Eighth Int. Congr. of Biomech. Human Kinetics Publishers 1123 1128
- Payne, A. H. Foot to Ground Contact Forces of Elite Runners Proc. of Eighth Int. Congr. of Biomech. Human Kinetics Publishers 746 753
- Bates, B. T. et al. Identification of Critical Variables Describing Ground Reaction Forces During Running Proc. of Eighth Int. Congr. of Biomech. Human Kinetics Publishers 635 640
- Falls, H. B. Humphereg L. D. Energy Costs of Running and Walking in Young Women Med. Sci. Sports 8 9 1976
- Godin, G. Shepard R. J. Body weight and the Energy Costs of Activity Arch. Environ. Health 27 289 1973
- Dietrick, J. E. Whedon, G D. Shorr E. Effects of Immobilization Upon Various Metabolic and Physiologic Function of Normal Men. Am. J. of Med. 4 3 36 1948
- Saltin, B. et al. Response to Exercise after Bed Rest and Training Circulation 38 1 78 1968
- Convertino, V. A. et al. Cardiorespiratory Responses to Exercise after Bed Rest in Men and Women Acta Astronautical 4 895 905 1977
- McMiken, D. F. Daniels J. T. Aerobic Requirements and Maximum Aerobic Power in Treadmill and Track Running Med Sci Sports 8 14 1976
- Thornton, W.
- Thornton, W. Comparison of Energy Costs of Active and Passive Treadmills JSC Internal Report 1981
- Thornton, W. A Means of Isolating Treadmill Shock and Vibration on Spacecraft NASA TM-100 474 1989