Objective: Our objective was to determine whether grip strength correlates with bone mineral density by body part. Participants and Methods: We studied the data on 86 forearms of 86 women, aged 60 years or older, who had been treated for distal radius fractures at our hospital between October 2007 and October 2013. All the patients underwent DXA (dual-energy x-ray absorptiometry) scans of the second to fourth lumbar vertebrae, the femoral neck, and the forearm bone (divided into 3 parts: ultra-distal [UD], mid-distal [MD], and proximal shaft [shaft]). The grip strength of the hand on the noninjured side was examined twice, and we used the average of the results for analysis. Statistical Analysis: Using Pearson product-moment correlation coefficients, we analyzed the DXA scan results (lumbar vertebrae, femur, and 3 forearm parts) for correlations with age, height, weight, body mass index (BMI), and grip strength. Results: The grip strength on the noninjured side correlated positively with the bone mineral densities of the forearm (UD, MD, and shaft) and the femur (neck), but not with those of the lumbar vertebrae. Discussion: The grip strength on the noninjured side had a stronger correlation with the bone mineral density of the proximal shaft (0.351), which has a high percentage of cortical bone than with those of MD (0.340) and UD (0.338). It also correlated with the mineral density of the femoral neck bone (0.263), but not with that of the lumbar vertebrae. Our results suggest a correlation between cortical bone amount and noninjured side grip strength. Conclusions: Our statistical analyses revealed that grip strength on the noninjured side correlated positively with forearm and femoral neck bone mineral densities, but not with lumbar vertebrae bone mineral densities, in middle-aged and elderly females with distal radius fracture. The resultant values indicated that 12.0 kg of grip is equivalent to −2.5 SD in DXA. Grip strength on the noninjured side can be a surrogate marker for screening osteoporosis.
