Assessment of femoral neck strength and bone mineral density changes following exercise using 3D-DXA images

Dermot O'Rourke, Belinda R. Beck, Amy T. Harding, Steven L. Watson, Peter Pivonka, Saulo Martelli

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


Physical exercise induces spatially heterogeneous bone changes in the proximal femur. Recent advances have enabled 3D dual-energy X-ray Absorptiometry (DXA)-based finite element (FE) models to estimate bone strength. However, its ability to detect exercise-induced BMD and strength changes is unclear. The aim of this study was to quantify the repeatability of vBMD and femoral neck strength obtained from 3D-DXA images and determine the changes due an exercise intervention. The DXA scans included pairs of same-day repeated scans from ten healthy females and pre- and post-exercise intervention scans of 26 males. FE models with element-by-element correspondence were generated by morphing a template mesh to each bone. BMD and femoral strength under single-leg-stance and sideways fall loading configurations were obtained for both groups and compared. In the repeated images, the total hip vBMD difference was 0.5 ± 2.5%. Element-by-element BMD differences reached 30 ± 50%. The strength difference in single-leg stance was 2.8 ± 13% and in sideways fall was 4.5% ± 19%. In the exercise group, strength changes were 6 ± 19% under single-leg stance and 1 ± 18% under sideways fall. vBMD parameters were weakly correlated to strength (R2 < 0.31). The exercise group had a mean bone accrual exceeding repeatability values in the femoral head and cortical regions. The case with the highest vBMD change (6.4%) caused 18% and −7% strength changes under single-leg stance and sideways fall. 3D-DXA technology can assess the effect of exercise interventions in large cohorts but its validity in individual cases should be interpreted with caution.

Original languageEnglish
Article number110315
Number of pages13
JournalJournal of Biomechanics
Publication statusPublished - 15 Apr 2021


  • BMD
  • DXA
  • Exercise
  • Femur
  • Strength


Dive into the research topics of 'Assessment of femoral neck strength and bone mineral density changes following exercise using 3D-DXA images'. Together they form a unique fingerprint.

Cite this