Bone stress injuries (BSI) are common among distance runners and research investigations examining risk factors for BSI among men are limited. Therefore, investigations are needed to determine if men with a history of BSI have skeletal properties that may heighten BSI incidence.
Objectives: To analyze differences in bone density, bone geometry, and estimates of bone strength in male runners with and without a BSI history.
Design: Cross-sectional.
Methods: We recruited 36 male distance runners ages 18–41 for this study. We used peripheral quantitative computed tomography (pQCT) to assess volumetric bone mineral density (vBMD, mg/mm3), bone geometry (total and cortical bone area, mm2), tibia robustness (total area/tibia length, mm) and estimates of bone strength (section modulus and polar strength-strain index, mm3) at 5 tibial sites.
Results: After adjusting for age, the BSI group had more slender tibias (9%), lower stress strain indices (−16%), lower section moduli (−17%) and smaller total cross-sectional (−11%) and cortical areas (−12%) at the 66% site of the tibia compared with controls (P < 0.05 for all). Similar differences were found at all other measurement sites. After adjusting for body size, differences in bone outcomes remained significant at the 66% site.
Conclusions: These results indicate that men with a history of BSI have lower estimated bending strength compared to controls because of narrower tibias. However, differences are largely attenuated in the distal ½ of the tibia after adjusting for body size. Thus, smaller tibia size, particularly at the mid-diaphysis, may be an important indicator for BSI incidence.