Peripheral quantitative computed tomography (pQCT) imaging of the tibia is commonly used to investigate factors influencing human bone strength. Physical activity is a dominating determinant of tibial bone strength, with disuse (spinal cord injury) and exercise (sprint athlete) groups associated with 60% lower and 25% greater tibial bone mass than that found in controls. The fibula is known to contribute from -6% to +19% to compressive force transmission in the shank, the proportion varying with joint angle and loading magnitude. Therefore, it may be less responsive to habitual loading and represent a novel target of new pQCT studies. Our group have previously found 22-51% differences in tibial bone mineral content (BMC) in a cross-sectional pQCT comparison between 9 spinal cord injury patients (SCI) (mean age 39.2±6.2y) representing prolonged disuse cases, and 9 age, height and mass-matched healthy controls (CTRL) (Rittweger, Goosey-Tolfrey, Cointry, & Ferretti, 2010). In addition, we found a significant 0.9-4.4% loss of tibial bone mass 14 days after 90 days of 6° head-down tilt bed rest (LTBR) in an interventional study in 25 young male volunteers (Rittweger et al., 2005).To examine the influence of habitual loading on fibula bone strength, pQCT scans from these previous studies were re-analysed to assess fibula bone strength. The SCI/CTRL study data consisted of 19 serial pQCT scans of fibula at 5% increments along tibia length from 5% to 95%, whereas scans were taken only at 4% and 66% distal-proximal tibia length in the LTBR study. In contrast to what was previously observed in the tibia, linear mixed effects models revealed no significant differences in fibula BMC, total bone area, cortical bone area, cortical bone density, periosteal or endocortical circumferences between SCI and CTRL (P > 0.16 in all cases) (Figure 1b shows total BMC in fibula, displayed alongside previously published tibia data in Figure 1a). In the LTBR study, only fibular trabecular BMD was significantly reduced (-1.4%, P = 0.04) by bed rest. Results suggest that the fibula is influenced little by habitual loading, particularly at diaphyseal (bone shaft) sites. Therefore examination of fibula bone strength could be considered as a novel alternative or adjunct to tibia measures, representing more metabolically than mechanically influenced bone.