Plantar flexion force is related to calcaneus bone ultrasonic parameters in postmenopausal women

The aim of this report was to study the relationship between the plantar flexion strength produced by contraction of the triceps surae (gastrocnemii-soleus) muscle and the calcaneus bone parameters assessed by quantitative ultrasound in 45 healthy postmenopausal women. Plantar flexion strength was related to calcaneus broadband ultrasound attenuation (BUA) (r = 0.43, P = 0.003) and to speed of sound (SOS) (r = 0.3, P = 0.04). Plantar flexion appeared to predict ultrasonic properties, independently of body weight (R2 = 19% and 9% for BUA and SOS, respectively). These results suggest that the stresses related to locomotion locally enhance bone remodeling but further studies are needed to identify the respective role of the compressive strains related to ground reaction forces at heel-strike and the muscular tensile strains applied on the calcaneus where the calcaneal tendon is inserted.