Talk:Spaceflight osteopenia

Cause
hello, could it be possible to know WHY does bone loss appear in zero gravity?Klinfran (talk) 17:43, 1 June 2011 (UTC)

Astronauts on Mars
In the cause section, It's written 'On Mars, where gravity is about one-third that of earth, the gravitational forces acting on astronauts' bodies are much lower, causing bones to decrease in mass and density.' as if we've sent some astronauts to mars and observed the effects on them. Sentencing here could be changed to "would be much lower" and "would cause bones to .." . Fotte (talk) 15:53, 22 May 2014 (UTC)

Irreversible skeletal damage
This phrase is in the introduction of the article, and conveys a sentiment of great danger from spaceflight. First, it's hard to really comprehend what irreversible skeletal damage even means (fractures? deformations?), but it sounds very frightening. In reality, astronauts returning from 6 months or longer, hardly experience crippling fractures or what-not after their time in microgravity. I know it says "There is concern that..." , which brings me to my second point: '''The source given for that sentence mentions nothing about permanent "damage" to bone nor concern about it. '''

Skeletal damage sounds like trauma and fracture, whereas what happens to the bone is (as is the title of the article) it becomes osteopenic (less dense or mineralised) due to less physical strain put on load bearing bones (see source [2] of the article, "Space Bones". NASA. October 1, 2001). This effect is absolutely reversible if a person's osteoblasts are still viable - the bone remodels itself according to its current needs, and when returning to 1 G, the bone remodels itself again to strengthen necessary areas (unless the person is incapacitated or otherwise bedridden) https://www.nasa.gov/pdf/516064main_ALG_ED_BoneDensity%2012-23-10.pdf

High doses of radiation however, does have a negative effect on osteoblasts and that can result in permanently lowered ability to mineralise and heal bones: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3401480/. Aging also reduces the effectiveness of osteoblasts resulting in osteopenia and osteoporosis, so I hardly think it's fair to use a powerful wording like "irreversible skeletal damage" - partly because it sounds ridiculous talking about the elderly having skeletal damage when it's just osteoporosis, but mostly because it isn't irreversible(!), and I think the same applies to astronauts.

Thanks for reading!

2.248.182.98 (talk) 19:48, 12 October 2019 (UTC)

Countermeasures
Countermeasures section is out of date and incorrect. Says that exercise has not been proven as effective as reducing osteopenia, but the treadmill and ARED have been proven as effective countermeasures on ISS. This article refers to no studies having been done as of 2005, which is way out of date and many have been done since then 108.84.177.165 (talk) 05:49, 13 December 2022 (UTC)