SUBREGIONAL ASSESSMENT OF BONE LOSS IN THE AXIAL SKELETON IN LONG-
TERM SPACEFLIGHT (SUBREGIONAL BONE)
Research Area: Bone and Muscle Physiology
Expeditions: 2 -8
Principal Investigator(s): ● Thomas F. Lang, PhD, University of California, San Francisco,
California
RESEARCH OBJECTIVES
Bone density scans are taken preflight, soon after landing, and again 1-year postflight to
understand the effects of microgravity on bone loss because of long-duration spaceflight. This is
a long-term study to understand the distribution of bone loss resulting from long-duration
spaceflight; the recovery of bone mass postflight in the year after landing; and the extent to
which these changes compare to the spread of bone mineral density measures in healthy Earth-
bound individuals.
EARTH BENEFITS
Additionally, comparison of bone
mineral density in the hip and
spine between space-flight crew
members and healthy normal
subjects improves understanding
of the prevalence of
osteoporosis between different
race and gender sub-groups on
Earth as well as in space crews.
SPACE BENEFITS
Bone loss, which can increase the
risk of fracture by weakening the
skeleton, is an established
medical risk in long-duration
spaceflight. There is little
information regarding which sub-regions of the most important skeletal sites, the spine and hip,
are most affected. Moreover, there is little information about the extent to which the lost bone
is recovered after spaceflight. This study provides the first information on spaceflight related
compartmental bone loss (magnitude and distribution) in the axial skeleton and on the extent
to which lost bone is recovered in the year following return. Furthermore, this study has
implications for the frequency of assignment to long-duration missions and for the health of the
astronauts in older age. It may also be of use in designing exercise or medicine
countermeasures to prevent bone loss.
ISS009E17466 – Expedition 9 Commander Gennady Padalka
performs an ultrasound bone scan on Flight Engineer and Science
Officer Edward (Mike) Fincke's heel using the Advanced Diagnostic
Ultrasound in Micro-G (ADUM) setup in the Destiny U.S. Laboratory
Module. The ADUM keyboard, flat screen display, and front control
panel are visible in the right field of view.