Relationship of Strength of Hand Grip, Low Back Muscles and Knee Joint Muscles, to Bone Mineral Densities of these Sites in Young Women

Kim, Ju Sung

Abstract

PURPOSE
The strength of hand grip, low back muscles and knee joint muscles were measured and then compared to the bone mineral density (BMD) of each forearm bones (including ulna and radius), lumbar spine, and femur in young women in order to identify the relationship between muscle strength and bone mineral density. METHOD: The BMD was measured with a Dual Energy X-ray Absorptiometry and muscle strength was measured with a handgrip dynamometer and a Cybex Norm. Data were analyzed with frequencies, percentages, means, and Pearson correlation coefficients. RESULT: 1) Higher grip strength correlated positively with higher BMD in the forearm (r=0.246, p=0.007), higher low back extensor strength with higher BMD in the femur (neck, trochanter and Ward's triangle)(r=0.323~0.226, p=0.003~0.043) and higher strength in the knee joint extensor with higher BMD in the lumbar spine (r=0.227, p=0.041), femur neck, and femur trochanter significantly (r=0.295~0.226, p=0.007~0.043). There was no significant correlation between the strength of low back extensors and BMD in the lumbar spine, now with strength of knee joint flexor and the BMD in the femur. 2) The muscle strength of each part of the body had significant positive correlations to each other part (r=0.255~0.728 p=0.021~0.000) CONCLUSION: The results of this study showed that with the development of a muscle there was an increased BMD of the corresponding part, and the BMD of each part was influenced by adjacent muscles. To promote the health of bones, it is important to strengthen the muscles of related bones, based on balanced development of all muscles.