Relationship between quadriceps strength and bone mineral density of the proximal tibia and distal forearm in women

Abstract

It is well known that there is a relationship between muscle strength and bone density, but it is uncertain whether this relationship is site specific. The aim of this study was to assess the relationship of quadriceps strength to site-specific bone mineral density (BMD) of the tibia and to BMD of the forearm. In 66 healthy women, aged 21-78 years, BMD was measured in the proximal tibia and the distal forearm by dual-photon absorptiometry. Isometric and isokinetic strength of the quadriceps was measured using an isokinetic dynamometer (Cybex II). Highly significant correlations between BMD of the proximal tibia and quadriceps strength were found (RS ranging from 0.79 to 0.84, p < 0.0001). Also, BMD of the distal forearm was correlated with quadriceps strength (RS ranging from 0.59 to 0.62, p < 0.0001). In a stepwise multiple regression analysis, quadriceps strength was a better predictor of tibial BMD than age, body height, or weight. However, age, height, and weight were more predictive of forearm BMD than quadriceps strength. When studying the pre- and postmenopausal women separately, quadriceps strength was correlated with BMD of the proximal tibia but not to forearm BMD. In conclusion, the study provides support for a site-specific relationship between muscle and bone.

Muscle Mass Is More Strongly Related to Hip Bone Mineral Density Than Is Quadriceps Strength or Lower Activity Level in Adults Over Age 50Year

“…Our population, enriched with overweight and obese subjects, allowed examination of the relationship between L-LBM, knee extensor strength, and BMD in these heavier groups, which is important because these factors are also associated with higher BMI. Although prior studies of healthy women demonstrated a relationship between BMD and knee extensor strength, (21,32) to our knowledge, the finding that knee extensor strength is not a significant predictor of BMD in obese adults has not been reported previously. This finding may indicate that increased body weight sufficiently loads the skeleton to maintain higher hip BMD in obese adults, whereas loading by the pull of the knee extensors is a more significant contributor to maintaining higher BMD in non-obese adults.…”

A Meta-Analysis of Bone Mineral Density in Collegiate Female Athletes

“…Still, athletes exhibiting higher bone impact usually show higher BMD values. As a result, BMD values in such athletes are generally higher unless notable discrepancies such as the female athlete triad 15,16 and other risk factors are seen for a prolonged period.…”

“…The spectrum of low energy availability, amenorrhea, and osteoporosis, either alone or in combination, are regarded as significant health risks for female athletes and are medically referred to as "the female triad." 15,16 Female athletes who participate in gymnastics, track, diving, dance, and synchronized swimming are affected most frequently. 1 Supporting this idea, women who exercise and maintain normal menstrual cycles seem to have higher BMD than amenorrheic women.…”

Association between moderate physical activity, spinal motion and back muscle strength in postmenopausal women with and without osteoporosis

“…Some studies have also demonstrated that higher loads at specific sites provided a more effective osteogenic stimulus than generally distributed loading at a lower intensity [33]. However, although a positive effect of physical activity on BMD has been reported by some authors [30,34,35], specific resistive loading beyond which bone is normally loaded during activities of daily living is usually required to achieve these effects [33]. This may explain why we did not find significant differences in BMD between our groups.…”