Current Rheumatology Reports

, Volume 12, Issue 3, pp 170–176 | Cite as

Mechanical Factors and Bone Health: Effects of Weightlessness and Neurologic Injury



Bone is a dynamic tissue with homeostasis governed by many factors. Among them, mechanical stimuli appear to be particularly critical for bone structure and strength. With removal of mechanical stimuli, a profound bone loss occurs, as best observed in the extreme examples following exposure to space flight or neurologic impairment. This review provides an overview of the changes in bone density and structure that occur during and after space flight as well as following neurologic injury from stroke and spinal cord injury. It also discusses the potential mechanisms through which mechanical stimuli are postulated to act on bone tissue.


Bone density Weightlessness Space Flight Spinal cord injury Stroke Mechanical stimuli 



No potential conflict of interest relevant to this article was reported.


Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

  1. 1.
    Wolff J: The Law of Bone Remodeling [in German]. Berlin, Germany: Springer; 1986.Google Scholar
  2. 2.
    Kohrt WM, Barry DW, Schwartz RS: Muscle forces or gravity: what predominates mechanical loading on bone? Med Sci Sports Exerc 2009, 41:2050–2055.CrossRefPubMedGoogle Scholar
  3. 3.
    McCarthy ID: Investigation of the role of venous pressure in bone changes during prolonged weightlessness. J Gravit Physiol 1996, 3:33–36.PubMedGoogle Scholar
  4. 4.
    Burger EH, Klein-Nulend J: Mechanotransduction in bone—role of the lacuno-canalicular network. FASEB J 1999, 13(Suppl):S101–S112.Google Scholar
  5. 5.
    Donahue SW, Jacobs CR, Donahue HJ: Flow-induced calcium oscillations in rat osteoblasts are age, loading frequency, and shear stress dependent. Am J Physiol Cell Physiol 2001, 281:C1635–C1641.PubMedGoogle Scholar
  6. 6.
    • Gurkan UA, Akkus O: The mechanical environment of bone marrow: a review. Ann Biomed Eng 2008, 36:1978–1991. This is an excellent review of the hydrostatic pressure changes and fluid shear stresses within bone marrow that may govern bone homeostasis.CrossRefPubMedGoogle Scholar
  7. 7.
    Robling AG, Castillo AB, Turner CH: Biomechanical and molecular regulation of bone remodeling. Annu Rev Biomed Eng 2006, 8:455–498.CrossRefPubMedGoogle Scholar
  8. 8.
    Rambaut PC, Goode AW: Skeletal changes during space flight. Lancet 1985, 2:1050–1052.CrossRefPubMedGoogle Scholar
  9. 9.
    • LeBlanc AD, Spector ER, Evans HJ, Sibonga JD: Skeletal responses to space flight and the bed rest analog: a review. J Musculoskelet Neuronal Interact 2007, 7:33–47. This is an excellent overview of the effects of space flight on bone over the years of the manned space program.PubMedGoogle Scholar
  10. 10.
    Smith SM, Wastney ME, O’Brien KO, et al.: Bone markers, calcium metabolism, and calcium kinetics during extended-duration space flight on the Mir space station. J Bone Miner Res 2005, 20:208–218.CrossRefPubMedGoogle Scholar
  11. 11.
    Holick MF: Perspective on the impact of weightlessness on calcium and bone metabolism. Bone 1998, 22(5 Suppl):105S–111S.CrossRefPubMedGoogle Scholar
  12. 12.
    Vico L, Collet P, Guignandon A, et al.: Effects of long-term microgravity exposure on cancellous and cortical weight-bearing bones of cosmonauts. Lancet 2000, 355:1607–1611.CrossRefPubMedGoogle Scholar
  13. 13.
    Lang T, LeBlanc A, Evans H, et al.: Cortical and trabecular bone mineral loss from the spine and hip in long-duration spaceflight. J Bone Miner Res 2004, 19:1006–1012.CrossRefPubMedGoogle Scholar
  14. 14.
    Lang TF, Leblanc AD, Evans HJ, Lu Y: Adaptation of the proximal femur to skeletal reloading after long-duration spaceflight. J Bone Miner Res 2006, 21:1224–1230.CrossRefPubMedGoogle Scholar
  15. 15.
    •• Keyak JH, Koyama AK, LeBlanc A, et al.: Reduction in proximal femoral strength due to long-duration spaceflight. Bone 2009, 44:449–453. This was the first study that examined proximal femur strength estimated by finite element analyses following long-duration microgravity exposure and that identified that the observed bone strength loss is greater than bone density loss.CrossRefPubMedGoogle Scholar
  16. 16.
    Sibonga JD, Evans HJ, Sung HG, et al.: Recovery of spaceflight-induced bone loss: bone mineral density after long-duration missions as fitted with an exponential function. Bone 2007, 41:973–978.CrossRefPubMedGoogle Scholar
  17. 17.
    LeBlanc A, Lin C, Shackelford L, et al.: Muscle volume, MRI relaxation times (T2), and body composition after spaceflight. J Appl Physiol 2000, 89:2158–2164.PubMedGoogle Scholar
  18. 18.
    Bakker AD, Soejima K, Klein-Nulend J, Burger EH: The production of nitric oxide and prostaglandin E(2) by primary bone cells is shear stress dependent. J Biomech 2001, 34:671–677.CrossRefPubMedGoogle Scholar
  19. 19.
    McAllister TN, Du T, Frangos JA: Fluid shear stress stimulates prostaglandin and nitric oxide release in bone marrow-derived preosteoclast-like cells. Biochem Biophys Res Commun 2000, 270:643–648.CrossRefPubMedGoogle Scholar
  20. 20.
    Bikle DD, Halloran BP, Morey-Holton E: Space flight and the skeleton: lessons for the earthbound. Endocrinologist 1997, 7:10–22.CrossRefPubMedGoogle Scholar
  21. 21.
    Cowin SC: On mechanosensation in bone under microgravity. Bone 1998, 22(5 Suppl):119S–125S.CrossRefPubMedGoogle Scholar
  22. 22.
    Burger EH, Klein-Nulend J: Microgravity and bone cell mechanosensitivity. Bone 1998, 22(5 Suppl):127S–130S.CrossRefPubMedGoogle Scholar
  23. 23.
    Colleran PN, Wilkerson MK, Bloomfield SA, et al.: Alterations in skeletal perfusion with simulated microgravity: a possible mechanism for bone remodeling. J Appl Physiol 2000, 89:1046–1054.PubMedGoogle Scholar
  24. 24.
    LeBlanc AD, Schneider VS, Evans HJ, et al.: Bone mineral loss and recovery after 17 weeks of bed rest. J Bone Miner Res 1990, 5:843–850.CrossRefPubMedGoogle Scholar
  25. 25.
    Laroche M: Intraosseous circulation from physiology to disease. Joint Bone Spine 2002, 69:262–269.CrossRefPubMedGoogle Scholar
  26. 26.
    Shackelford LC, LeBlanc AD, Driscoll TB, et al.: Resistance exercise as a countermeasure to disuse-induced bone loss. J Appl Physiol 2004, 97:119–129.CrossRefPubMedGoogle Scholar
  27. 27.
    Greenleaf JE: Physiology of Prolonged Bed Rest [technical memorandum]. Washington, DC: NASA; 1988.Google Scholar
  28. 28.
    Smith SM, Zwart SR, Block G, et al.: The nutritional status of astronauts is altered after long-term space flight aboard the International Space Station. J Nutr 2005, 135:437–443.PubMedGoogle Scholar
  29. 29.
    Almeida M, Han L, Martin-Millan M, et al.: Skeletal involution by age-associated oxidative stress and its acceleration by loss of sex steroids. J Biol Chem 2007, 282:27285–27297.CrossRefPubMedGoogle Scholar
  30. 30.
    Ozgocmen S, Kaya H, Fadillioglu E, et al.: Role of antioxidant systems, lipid peroxidation, and nitric oxide in postmenopausal osteoporosis. Mol Cell Biochem 2007, 295:45–52.CrossRefPubMedGoogle Scholar
  31. 31.
    Hamilton SA, Pecaut MJ, Gridley DS, et al.: A murine model for bone loss from therapeutic and space-relevant sources of radiation. J Appl Physiol 2006, 101:789–793.CrossRefPubMedGoogle Scholar
  32. 32.
    Bushinsky DA, Ori Y: Effects of metabolic and respiratory acidosis on bone. Curr Opin Nephrol Hypertens 1993, 2:588–596.PubMedGoogle Scholar
  33. 33.
    Strollo F, Riondino G, Harris B, et al.: The effect of microgravity on testicular androgen secretion. Aviat Space Environ Med 1998, 69:133–136.PubMedGoogle Scholar
  34. 34.
    • Carda S, Cisari C, Invernizzi M, Bevilacqua M: Osteoporosis after stroke: a review of the causes and potential treatments. Cerebrovasc Dis 2009, 28:191–200. This is an excellent review on the effects of stroke on bone.CrossRefPubMedGoogle Scholar
  35. 35.
    Pang MY, Ashe MC, Eng JJ: Muscle weakness, spasticity and disuse contribute to demineralization and geometric changes in the radius following chronic stroke. Osteoporos Int 2007, 18:1243–1252.CrossRefPubMedGoogle Scholar
  36. 36.
    Pang MY, Ashe MC, Eng JJ: Tibial bone geometry in chronic stroke patients: influence of sex, cardiovascular health, and muscle mass. J Bone Miner Res 2008, 23:1023–1030.CrossRefPubMedGoogle Scholar
  37. 37.
    Celik B, Ones K, Ince N: Body composition after stroke. Int J Rehab Res 2008, 31:93–96.CrossRefGoogle Scholar
  38. 38.
    Worthen LC, Kim CM, Kautz SA, et al.: Key characteristics of walking correlate with bone density in individuals with chronic stroke. J Rehabil Res Dev 2005, 42:761–768.CrossRefPubMedGoogle Scholar
  39. 39.
    Jiang SD, Dai LY, Jiang LS: Osteoporosis after spinal cord injury. Osteoporos Int 2006, 17:180–192. (Published erratum appears in Osteoporos Int 2006, 17:1278–1281.)CrossRefPubMedGoogle Scholar
  40. 40.
    Dauty M, Perrouin Verbe B, Maugars Y, et al.: Supralesional and sublesional bone mineral density in spinal cord-injured patients. Bone 2000, 27:305–309.CrossRefPubMedGoogle Scholar
  41. 41.
    Frey-Rindova P, de Bruin ED, Stüssi E, et al.: Bone mineral density in upper and lower extremities during 12 months after spinal cord injury measured by peripheral quantitative computed tomography. Spinal Cord 2000, 38:26–32.CrossRefPubMedGoogle Scholar
  42. 42.
    Eser P, Frotzler A, Zehnder Y, et al.: Relationship between the duration of paralysis and bone structure: a pQCT study of spinal cord injured individuals. Bone 2004, 34:869–880.CrossRefPubMedGoogle Scholar
  43. 43.
    Alekna V, Tamulaitiene M, Sinevicius T, Juocevicius A: Effect of weight-bearing activities on bone mineral density in spinal cord injured patients during the period of the first two years. Spinal Cord 2008, 46:727–732.CrossRefPubMedGoogle Scholar
  44. 44.
    Jiang SD, Jiang LS, Dai LY: Mechanisms of osteoporosis in spinal cord injury. Clin Endocrinol (Oxf) 2006, 65:555–565.CrossRefGoogle Scholar
  45. 45.
    Marenzana M, Chenu C: Sympathetic nervous system and bone adaptive response to its mechanical environment. J Musculoskelet Neuronal Interact 2008, 8:111–120.PubMedGoogle Scholar
  46. 46.
    Marsden J, Gibson LM, Lightbody CE, et al.: Can early onset bone loss be effectively managed in post-stroke patients? An integrative review of the evidence. Age Ageing 2008, 37:142–150.CrossRefPubMedGoogle Scholar
  47. 47.
    Eng JJ, Pang MY, Ashe MC: Balance, falls, and bone health: role of exercise in reducing fracture risk after stroke. J Rehabil Res Dev 2008, 45:297–313.CrossRefPubMedGoogle Scholar
  48. 48.
    Biering-Sorensen F, Hansen B, Lee BS: Non-pharmacological treatment and prevention of bone loss after spinal cord injury: a systematic review. Spinal Cord 2009, 47:508–518.CrossRefPubMedGoogle Scholar
  49. 49.
    Giangregorio L, McCartney N: Bone loss and muscle atrophy in spinal cord injury: epidemiology, fracture prediction, and rehabilitation strategies. J Spinal Cord Med 2006, 29:489–500.PubMedGoogle Scholar
  50. 50.
    Gilchrist NL, Frampton CM, Acland RH, et al.: Alendronate prevents bone loss in patients with acute spinal cord injury: a randomized, double-blind, placebo-controlled study. J Clin Endocrinol Metab 2007, 92:1385–1390.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Division of Rheumatology, College of MedicineMayo ClinicRochesterUSA

Personalised recommendations