Quantitative forearm muscle strength influences radial bone mineral density in osteoporotic and healthy males.

Fractures are not rare in male osteoporosis and bone mineral density (BMD) measurement is used in the diagnosis and monitoring, preventing and/or treating the disease. Muscle strength and BMD are highly related to each other. The distal radius is one of the most common sites of osteoporotic fractures. The relationship of quantitative muscle strength and BMD of the forearm has not yet been established. The objective of this study was to assess forearm muscle strength and grip strength in relation to BMD in 46 osteoporotic and randomly selected 45 healthy male participants. Forearm muscle strength and BMD were quantitatively measured using an isokinetic dynamometer and dual-energy-X-ray-absorptiometry (DEXA), respectively. Significant correlation was found among the muscle strength and dominant forearm BMD in 60 and 120 deg/s velocities. In the non-dominant arm, the 120 deg/s velocity was only significantly positively correlated to forearm BMD. Pearson's Product coefficient presented a moderate correlation between muscle strength and BMD at the dominant arms of both groups, whereas, the difference in the non-dominant forearm came from the difference of usage frequency. In conclusion, quantitative forearm muscle strength and BMD is moderately correlated and exercise can be advised to prevent distal radius fractures in male osteoporosis.