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Astronaut Bone Medical Standards Derived from Finite Element [FE] Modeling of QCT Scans from Populations Studies (FEMQCT)
Principal Investigator
Research Area:
Biomedical countermeasures
Bone and calcium physiology
Species Studied
Scientific Name: Homo sapiens Species: Human

This study was a follow-up to the recommendations from two advisory panels – the Bone Summit in June 2010 and the Finite Element (FE) Task Group in October 2011. Both concurred that improved medical standards for bone are required for astronauts. In a previous flight study, Quantitative computed tomography (QCT) hip scans of astronauts who served on the International Space Station (ISS) were performed before and after missions and analyzed by finite element modeling (FEM) to characterize space flight effects on hip bone strength. The compelling data generated by this computational tool led these clinical experts in areal bone mineral density (aBMD) and osteoporosis to acknowledge that FEM of QCT data provides an improved detection of space flight-induced changes to hip bone strength, over DXA measurement of areal BMD.

This study had the following specific aims:

  1. Develop a dataset of FE hip strengths for subjects a) with ages covering the age range of the astronauts, and b) for which fractures outcome data have been collected.
  2. Review and evaluate dataset by FE Task Group members to suggest methods by which FE strength cutoffs from this dataset could supplement current areal BMD-based standards for the following:
    a) a non-permissible outcome (POL) for hip bone strength after space flight to establish level of countermeasure efficacy, b) an additional metric for screening bone healthy in applicants to the astronaut corps who fail to meet the bone medical standard of hip T-score>-1.0, c) a fitness-for-flight standard in astronauts for a second long-duration mission, and d) an index for assessing an astronaut’s risk for overloading the hip due to certain post-mission physical activities.
  3. A manuscript of FE Task Group opinions.

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Michalski AS, Amin S, Cheung AM, Cody DD, Keyak JH, Lang TF, Nicolella DP, Orwoll ES, Boyd SK, and Sibonga JD. Hip load capacity cut-points for Astronaut Skeletal Health NASA Finite Element Strength Task Group Recommendations. NPJ Microgravity. 2019. March; 5(1):6. [DOI]

Finite element analysis
Bone and bones
Bone mineral density

Absolute change
DXA scan time, days
Fall load
Non-linear fall load
Non-linear stance load
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Ground 05/01/2009 In Progress

Human Research Program (HRP) Human Research Roadmap (HRR) Information
Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

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Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Eric Gallagher
Institutional Support
National Aeronautics and Space Administration (NASA)
Alternate Experiment Name
FE Strength Cutoff II
Proposal Date
Proposal Source
Directed Research