Reconsideration of calf circumference as an item of physical therapy evaluation indicating muscle histology

Abstract

[Purpose] The purpose of this study was to contribute to the reconsideration of calf circumference measurement as a physical therapy evaluation item. We aimed to assess the correlation between maximum calf circumference and the histological factors of the soleus muscle as well as the strength of ankle plantar flexion. [Subject] Fifty healthy adults who had no history of lower limb pathology participated in this study. [Methods] With the length of the leg considered to be 100%, the maximum calf circumference was measured at 26% of the length from the head of the fibula. We assumed that the soleus is a pennate muscle and measured the thickness and length of muscle fibers (histological factors) using ultrasonography. Ankle plantar flexion was used to measure the power of the soleus muscle. [Results] The histological factors were associated with maximum calf circumference, and the strength of ankle plantar flexion. [Conclusion] Our results suggest that maximum calf circumference reflects histological factors of the soleus muscle and the strength of ankle plantar flexion.