Related Experiment Video
Updated: May 10, 2026
Longitudinal Evaluation of Mouse Hind Limb Bone Loss After Spinal Cord Injury using Novel, in vivo, Methodology
Published on: December 7, 2011
Active-resisted stance modulates regional bone mineral density in humans with spinal cord injury
Shauna Dudley-Javoroski1, Richard K Shields
1Department of Physical Therapy & Rdhabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
Objective:
In people with spinal cord injury (SCI), active-resisted stance using electrical stimulation of the quadriceps delivered a therapeutic stress to the femur (∼150% of body weight) and attenuated bone mineral density (BMD) decline. In standard densitometry protocols, BMD is averaged over the entire bone cross-section. An asymmetric adaptation to mechanical load may be masked by non-responding regions. The purpose of this study was to test a novel method to assess regional BMD of the femur in individuals with SCI. We hypothesize that there will be regional bone-sparing changes as a result of active-resisted stance.
Design:
Mixed cross-sectional and longitudinal.
Setting:
Research laboratory.
Participants:
Twelve individuals with SCI and twelve non-SCI controls.
Intervention:
Individuals with SCI experienced active-resisted stance or passive stance for up to 3 years.
Outcome Measures:
Peripheral quantitative computed tomography images from were partitioned so that femur anatomic quadrants could be separately analyzed.
Results:
Over 1.5 years, the slope of BMD decline over time was slower at all quadrants for the active-resisted stance limbs. At >2 years of training, BMD was significantly higher for the active-resisted stance group than for the passive stance group (P = 0.007). BMD was preferentially spared in the posterior quadrants of the femur with active-resisted stance.
Conclusions:
A regional measurement technique revealed asymmetric femur BMD changes between passive stance and active-resisted stance. Future studies are now underway to better understand other regional changes in BMD after SCI.
