Summary: Condition wherein the force of gravity is less than or is decreased below that on the surface of the earth. This is expressed as being between 0 and 1 g.

Top Publications

  1. Coward S, Selden C, Mantalaris A, Hodgson H. Proliferation rates of HepG2 cells encapsulated in alginate are increased in a microgravity environment compared with static cultures. Artif Organs. 2005;29:152-8 pubmed
    ..This allows a greater level of hepatic function to be expressed in a given volume, offering clear advantages for the design of liver support systems. ..
  2. Kordi M, Kluge N, Kloeckner M, Russomano T. Gender influence on the performance of chest compressions in simulated hypogravity and microgravity. Aviat Space Environ Med. 2012;83:643-8 pubmed
    ..difference in the effectiveness of performing ECCs using a body suspension device to simulate lunar and Martian hypogravity and microgravity...
  3. Ivanenko Y, Labini F, Cappellini G, Macellari V, McIntyre J, Lacquaniti F. Gait transitions in simulated reduced gravity. J Appl Physiol (1985). 2011;110:781-8 pubmed publisher
  4. Dalmarco G, Calder A, Falcão F, de Azevedo D, Sarkar S, Evetts S, et al. Evaluation of external cardiac massage performance during hypogravity simulation. Conf Proc IEEE Eng Med Biol Soc. 2006;1:2904-7 pubmed
    ..in critical care medicine, plans must be in place for cardiopulmonary resuscitation in both microgravity and hypogravity (i.e. on the surface of the Moon or Mars)...
  5. Guevorkian K, Valles J. Swimming Paramecium in magnetically simulated enhanced, reduced, and inverted gravity environments. Proc Natl Acad Sci U S A. 2006;103:13051-6 pubmed
    ..capability to enhance, reduce, and even invert the effective buoyancy of cells and thus simulate hypergravity, hypogravity, and inverted gravity environments...
  6. Lynch S, Brodie E, Matin A. Role and regulation of sigma S in general resistance conferred by low-shear simulated microgravity in Escherichia coli. J Bacteriol. 2004;186:8207-12 pubmed
    ..Since sigma s regulatory processes are influenced by mRNA and protein-folding patterns, the data suggest that SMG may affect these configurations. ..
  7. Nickerson C, Ott C, Mister S, Morrow B, Burns Keliher L, Pierson D. Microgravity as a novel environmental signal affecting Salmonella enterica serovar Typhimurium virulence. Infect Immun. 2000;68:3147-52 pubmed
    ..Our results indicate that the environment created by simulated microgravity represents a novel environmental regulatory factor of Salmonella virulence. ..
  8. Ivanenko Y, Grasso R, Macellari V, Lacquaniti F. Control of foot trajectory in human locomotion: role of ground contact forces in simulated reduced gravity. J Neurophysiol. 2002;87:3070-89 pubmed
    ..The results did not depend on the specific instruction given to the subject. Therefore we conclude that minimal contact forces are sufficient for accurate foot trajectory control. ..
  9. Demain A, Fang A. Secondary metabolism in simulated microgravity. Chem Rec. 2001;1:333-46 pubmed
    ..With respect to S. hygroscopicus, addition of Teflon beads to the RWB reversed the inhibition of growth, but rapamycin production was still markedly inhibited, and the distribution did not revert back to a preferential cellular site. ..

More Information


  1. Gómez Bruton A, González Agüero A, Gómez Cabello A, Matute Llorente Á, Casajús J, Vicente Rodríguez G. Swimming and bone: Is low bone mass due to hypogravity alone or does other physical activity influence it?. Osteoporos Int. 2016;27:1785-93 pubmed publisher
    ..Male-SWI spend less time in VPA and MVPA than male-GC, which partly explains the lower BMD values in SWI than CG. Swimming may displace weight-bearing VPA with serious implications on bone health. ..
  2. Albery W. Acceleration in other axes affects +Gz tolerance: dynamic centrifuge simulation of agile flight. Aviat Space Environ Med. 2004;75:1-6 pubmed
    ..Gy acceleration in conjunction with Gz acceleration can enhance G tolerance. Gx acceleration in addition to Gz acceleration can reduce G tolerance. ..
  3. Ricci C, Boschetti C. Bdelloid rotifers as model system to study developmental biology in space. Adv Space Biol Med. 2003;9:25-39 pubmed
    ..The significance of the result as well as the use of instruments to simulate gravity perturbations are discussed. ..
  4. Newman D. Life in extreme environments: how will humans perform on Mars?. Gravit Space Biol Bull. 2000;13:35-47 pubmed
  5. Gielen C, van Bolhuis B. Task-dependent reduction of the number of degrees of freedom in sensorimotor systems. Brain Res Brain Res Rev. 1998;28:136-42 pubmed
  6. Clement G. Alteration of eye movements and motion perception in microgravity. Brain Res Brain Res Rev. 1998;28:161-72 pubmed
  7. Sides M, Vernikos J, Convertino V, Stepanek J, Tripp L, Draeger J, et al. The Bellagio Report: Cardiovascular risks of spaceflight: implications for the future of space travel. Aviat Space Environ Med. 2005;76:877-95 pubmed
    ..Data need to be collected regarding the emerging field of suborbital and orbital civilian space travel, to allow for sound risk assessment. ..
  8. Kergoat H, Lovasik J. Seven-degree head-down tilt reduces choroidal pulsatile ocular blood flow. Aviat Space Environ Med. 2005;76:930-4 pubmed
    ..This finding may have important implications regarding visual performance in space crewmembers placed in prolonged microgravity environments. ..
  9. Goodman L, Banks R, Grissett J, Saunders P. Heart rate and blood pressure responses to +Gz following varied-duration -Gz. Aviat Space Environ Med. 2000;71:137-41 pubmed
    ..These results suggest there may be a threshold effect for HR response. Consequently, vasoconstrictor response is a critical adaptive mechanism during +Gz when preceded by long (>10 s) -Gz exposures. ..
  10. Kim C, Ih J. On the horizontal wobbling of an object levitated by near-field acoustic levitation. Ultrasonics. 2007;46:331-5 pubmed
    ..It was shown that the predicted wobbling frequencies agreed with measured ones well. Finally, a safe zone was suggested to avoid the unstable movement of an object. ..
  11. Riviere D. [Physiological changes in microgravity]. Bull Acad Natl Med. 2009;193:1633-44 pubmed
    ..These changes do not seem to impair health or performance. Humans seem able to adapt to long-term exposure to microgravity, but disorders can occur on return to Earth. In-flight preventive measures need be developed. ..
  12. Wade C, Ortiz R, Baer L. Increases in body mass of rats during spaceflight: models and measurements. Aviat Space Environ Med. 2000;71:1126-30 pubmed
    ..The increase in body mass during spaceflight suggests that the rat may provide a viable model for metabolic studies in which changes during spaceflight may be predicted in part by ground-based hypergravity studies. ..
  13. Kuno H, Yamamoto N, Kurokawa N, Yamamoto T, Tagawa Y. Characteristic activities of lower limbs with body weight support ratio. Conf Proc IEEE Eng Med Biol Soc. 2012;2012:4800-3 pubmed publisher
    ..Decrease of ankle joint moment was greatest compared with other moment. Decrease of peaks of muscle activity by BWS was observed during stance phase, and did not almost change during swing phase. ..
  14. Vukanti R, Model M, Leff L. Effect of modeled reduced gravity conditions on bacterial morphology and physiology. BMC Microbiol. 2012;12:4 pubmed publisher
    ..In addition, these results demonstrate that bacterial physiological responses to MRG conditions vary with growth medium and growth phase demonstrating that nutrient resources are a modulator of response. ..
  15. Shender B. Keeping you informed of the latest advances in science and technology. Aviat Space Environ Med. 2002;73:320 pubmed
  16. Labini F, Ivanenko Y, Cappellini G, Gravano S, Lacquaniti F. Smooth changes in the EMG patterns during gait transitions under body weight unloading. J Neurophysiol. 2011;106:1525-36 pubmed publisher
    ..A lack of discontinuous changes in the pattern of speed-dependent locomotor characteristics in a hypogravity environment is consistent with the idea of a continuous shift in the state of a given set of central pattern ..
  17. Ingalls C, Wenke J, Armstrong R. Time course changes in [Ca2+]i, force, and protein content in hindlimb-suspended mouse soleus muscles. Aviat Space Environ Med. 2001;72:471-6 pubmed
    ..It appears that resting cytosolic Ca2+ homeostasis is disturbed soon after the initiation of hindlimb suspension, and these elevations in [Ca2+]i may play a role in initiating soleus muscle atrophy. ..
  18. Ohnishi T, Takahashi A, Wang X, Ohnishi K, Ohira Y, Nagaoka S. Accumulation of a tumor suppressor p53 protein in rat muscle during a space flight. Mutat Res. 1999;430:271-4 pubmed
    ..35-fold increase in p53 protein compared with that of SC-9 rats. These results suggest that the accumulation of cellular p53 protein induced by space environments occurs not only in rat skin cells, but also in rat muscle cells. ..
  19. Huang Y, Dai Z, Ling S, Zhang H, Wan Y, Li Y. Gravity, a regulation factor in the differentiation of rat bone marrow mesenchymal stem cells. J Biomed Sci. 2009;16:87 pubmed publisher
  20. Augurelle A, Penta M, White O, Thonnard J. The effects of a change in gravity on the dynamics of prehension. Exp Brain Res. 2003;148:533-40 pubmed
    ..We suggest that a central representation of the new gravitational field was rapidly acquired through the incoming vestibular and somatic sensory information. ..
  21. Liang S, Lan B. Comparison of newtonian and special-relativistic trajectories with the general-relativistic trajectory for a low-speed weak-gravity system. PLoS ONE. 2012;7:e34720 pubmed publisher
  22. Zhang L, Sun B, Cao X, Liu C, Yu Z, Zhang L, et al. Effectiveness of intermittent -Gx gravitation in preventing deconditioning due to simulated microgravity. J Appl Physiol (1985). 2003;95:207-18 pubmed
    ..The present work suggests that system specificity in responsiveness to intermittent gravity exposure should be considered one of the prerequisites in proposing intermittent artificial gravity as a potential countermeasure. ..
  23. Katayama K, Sato K, Akima H, Ishida K, Takada H, Watanabe Y, et al. Acceleration with exercise during head-down bed rest preserves upright exercise responses. Aviat Space Environ Med. 2004;75:1029-35 pubmed
    ..0 to 43.9 +/- 8.9 ml x kg(-1) x min(-1)). These results suggest that short-arm centrifuge-induced artificial gravity with exercise training is effective in maintaining respiratory and cardiovascular responses to upright exercise. ..
  24. El Haj A, Wood M, Thomas P, Yang Y. Controlling cell biomechanics in orthopaedic tissue engineering and repair. Pathol Biol (Paris). 2005;53:581-9 pubmed
    ..The effects of these factors on successful bone tissue formation observed in increased matrix protein synthesis due to the optimisation of mechano-transduction pathways is discussed. ..
  25. Carvalho H, Teel L, Goping G, O Brien A. A three-dimensional tissue culture model for the study of attach and efface lesion formation by enteropathogenic and enterohaemorrhagic Escherichia coli. Cell Microbiol. 2005;7:1771-81 pubmed
  26. Salmi M, ul Haque A, Bushart T, Stout S, Roux S, Porterfield D. Changes in gravity rapidly alter the magnitude and direction of a cellular calcium current. Planta. 2011;233:911-20 pubmed publisher
    ..These results indicate that gravity perception in single plant cells may be mediated by mechanosensitive calcium channels, an idea consistent with some previously proposed models of plant gravity perception...
  27. Brown A. Circumnutations: from Darwin to space flights. Plant Physiol. 1993;101:345-8 pubmed
  28. Van Oostveldt P, Vangestel S, Meesen G, Poffyn A, Coene E, Schelfhout V, et al. Single cell and tissue specific methods for evaluation of radiation and microgravity effects. Mutat Res. 1999;430:235-40 pubmed
    ..This is a promising method for single cell analysis and the study of the effects of ionizing radiation at low particle flux density. ..
  29. Kirenskaia A, Tomilovskaia E, Novototskiĭ Vlasov V, Kozlovskaia I. [The effects of simulated microgravity on characteristics of slow presaccadic potentials]. Fiziol Cheloveka. 2006;32:10-9 pubmed
  30. Agrawal S, Fattah A. Theory and design of an orthotic device for full or partial gravity-balancing of a human leg during motion. IEEE Trans Neural Syst Rehabil Eng. 2004;12:157-65 pubmed
    ..A first prototype has been constructed to demonstrate the effectiveness of the idea. Future prototypes will have parameters that will be tuned to the geometry and inertia of a human subject and be tailored to an individual's needs. ..
  31. Monje O, Stutte G, Goins G, Porterfield D, Bingham G. Farming in space: environmental and biophysical concerns. Adv Space Res. 2003;31:151-67 pubmed
  32. Schneider S, Amonette W, Blazine K, Bentley J, Lee S, Loehr J, et al. Training with the International Space Station interim resistive exercise device. Med Sci Sports Exerc. 2003;35:1935-45 pubmed
    ..Bed rest and spaceflight studies are needed to evaluate the effectiveness of the iRED to prevent microgravity deconditioning. ..
  33. Prisk G. The lung in space. Clin Chest Med. 2005;26:415-38, vi pubmed
    ..In microgravity, lungs may be at greater risk to the effects of inhaled aerosols. ..
  34. Mergner T, Rosemeier T. Interaction of vestibular, somatosensory and visual signals for postural control and motion perception under terrestrial and microgravity conditions--a conceptual model. Brain Res Brain Res Rev. 1998;28:118-35 pubmed
    ..Such an integrative conceptual framework will be helpful for reaching a general understanding of spatially oriented behavior. ..
  35. Versari S, Longinotti G, Barenghi L, Maier J, Bradamante S. The challenging environment on board the International Space Station affects endothelial cell function by triggering oxidative stress through thioredoxin interacting protein overexpression: the ESA-SPHINX experiment. FASEB J. 2013;27:4466-75 pubmed publisher
  36. Cheung B, Bateman W. G-transition effects and their implications. Aviat Space Environ Med. 2001;72:758-62 pubmed
    ..and psychophysical effects induced by rapid changes in gravitoinertial forces, alternating between hypogravity (<1 Gz) and hypergravity (>1 Gz) and vice versa...
  37. Minetti A, Ivanenko Y, Cappellini G, Dominici N, Lacquaniti F. Humans running in place on water at simulated reduced gravity. PLoS ONE. 2012;7:e37300 pubmed publisher
    ..The results showed that a hydrodynamic model of lizards running on water can also be applied to humans, despite the enormous difference in body size and morphology. ..
  38. Riepl R, Drummer C, Lehnert P, Gerzer R, Otto B. Influence of microgravity on plasma levels of gastroenteropancreatic peptides: a case study. Aviat Space Environ Med. 2002;73:206-10 pubmed
    ..These results have to be confirmed in more subjects in space to be able to link changes of gastroenteropancreatic peptide release to alterations of gastrointestinal functions. ..
  39. Carlsson S, Bertilaccio M, Ballabio E, Maier J. Endothelial stress by gravitational unloading: effects on cell growth and cytoskeletal organization. Biochim Biophys Acta. 2003;1642:173-9 pubmed
    ..We hypothesize that the reduction in the amounts of actin in response to microgravity represents an adaptative mechanism to avoid the accumulation of redundant actin fibers. ..
  40. Islamov R, Tyapkina O, Bukharaeva E, Yagodina L, Ibragimova N, Valiullina V, et al. Expression of choline acetyltransferase in rat spinal motoneurons after antiorthostatic suspension. Dokl Biol Sci. 2007;414:205-7 pubmed
  41. Broutin L Hermite I, Ries Kautt M, Ducruix A. 1.7 A x-ray structure of space-grown collagenase crystals. Acta Crystallogr D Biol Crystallogr. 2000;56:376-8 pubmed
    ..Alternate conformations were revealed for several residues, in particular Tyr99, suggesting a gate mechanism of recognition. ..
  42. Miyoshi T, Nakazawa K, Tanizaki M, Sato T, Akai M. Altered activation pattern in synergistic ankle plantarflexor muscles in a reduced-gravity environment. Gait Posture. 2006;24:94-9 pubmed
    ..Such dissociated activation of the synergistic ankle plantarflexors might be relevant to the different roles required of these muscles in functional motor tasks. ..
  43. Horneck G. Impact of microgravity on radiobiological processes and efficiency of DNA repair. Mutat Res. 1999;430:221-8 pubmed
  44. Kirkpatrick A, Doarn C, Campbell M, Barnes S, Broderick T. Manual suturing quality at acceleration levels equivalent to spaceflight and a lunar base. Aviat Space Environ Med. 2008;79:1065-6 pubmed
    ..16 G) will likely not present challenges beyond those faced in addressing the tremendous logistical and training obstacles to providing experienced and equipped surgeons on-board such a mission. ..
  45. Nasledov G. [The role of electro-mechanical coupling in development of experimental atrophy of skeletal muscles]. Ross Fiziol Zh Im I M Sechenova. 2003;89:302-12 pubmed
    ..It was supposed that denervation and immobilization are the pathogenic factors for triggering the excitation-contraction coupling, whereas unloading is the factor which evokes active adaptation of this system. ..
  46. Meloni M, Galleri G, Pippia P, Cogoli Greuter M. Cytoskeleton changes and impaired motility of monocytes at modelled low gravity. Protoplasma. 2006;229:243-9 pubmed
  47. Pierno S, Desaphy J, Liantonio A, De Bellis M, Bianco G, De Luca A, et al. Change of chloride ion channel conductance is an early event of slow-to-fast fibre type transition during unloading-induced muscle disuse. Brain. 2002;125:1510-21 pubmed
    Disuse of postural slow-twitch muscles, as it occurs in hypogravity, induces a slow-to-fast myofibre type transition...
  48. Yang C, Chen Y, Mao G, Ma L, Wang Z, Zhang Y. [Effects of acute hypobaric hypoxia on gastric emptying and intestinal propulsion: experiment with rats]. Zhonghua Yi Xue Za Zhi. 2006;86:2391-4 pubmed
    ..Mosapride may alleviate the inhibitory effect of hypobaric hypoxia on gastric emptying. Decrease of plasma motilin and elevation of NO level may be the main mechanism of inhibition of gastrointestinal motility by hypobaric hypoxia. ..
  49. Breniere Y. Simulation of gait and gait initiation associated with body oscillating behavior in the gravity environment on the moon, mars and Phobos. Biol Cybern. 2001;84:261-7 pubmed
    ..More generally, the simulation allows us to establish and discuss the conditions for gait adaptability that result from the biomechanical constraints particular to each gravity system. ..
  50. Cardus D. Cardiovascular effects of a fractional -Gz force during a relatively prolonged exposure. J Gravit Physiol. 1996;3:65-7 pubmed
    Artificial hypogravity was created by having subjects remain in a supine position while undergoing rotation in an artificial gravity simulator...
  51. Horneck G, Facius R, Reichert M, Rettberg P, Seboldt W, Manzey D, et al. HUMEX, a study on the survivability and adaptation of humans to long-duration exploratory missions, part I: lunar missions. Adv Space Res. 2003;31:2389-401 pubmed
    ..Finally, a European strategy leading to a potential European participation in future human exploratory missions has been recommended. ..
  52. Haigneré C, Jonas P, Khayat P, Girot G. Bone height measurements around a dental implant after a 6-month space flight: a case report. Int J Oral Maxillofac Implants. 2006;21:450-4 pubmed
    ..Peri-implant bone levels remained stable after 6 months in microgravity, and the implant continued to function without complications. ..
  53. Buravkova L, Merzlikina N. [Remodeling of the actin cytoskeleton of cultivated human endothelium cells during clinostatting]. Aviakosm Ekolog Med. 2004;38:56-61 pubmed
    ..These data suggest sensitivity of the EC cytoskeleton to changes in the gravity vector. Remodeling of the actin skeleton in a changed gravity is reversible and proceeds more rapidly than recovery. ..