Sonographic studies of human soleus and gastrocnemius muscle architecture: gender variability

Abstract

The purpose of this study was to establish if there are gender differences in muscle architecture in relaxed human soleus and gastrocnemius muscles of normal, live subjects. Ultrasonography was used to measure fiber bundle length, muscle thickness, and angles of pennation in a total of ten predetermined sites in the medial and lateral heads of gastrocnemius and the anterior and posterior soleus in 19 males and 16 females. Percentage differences between males and females for each parameter were recorded. Gender differences were statistically analyzed using multivariate analysis of variance. In the gastrocnemius and soleus muscles of males and females the differences between the overall fiber bundle length, angle of pennation and muscle thickness were statistically significant (P < 0.05). Overall, females were found to have longer average muscle fiber bundle length and males thicker muscles and larger angles of pennation. The greatest percentage differences of the architectural parameters between males and females were in the posterior soleus: 13% difference in fiber length and 26% difference in angle of pennation in the midline of posterior soleus and 26% difference in muscle thickness of the lateral part of posterior soleus. No correlation was found between leg length and fiber length, angle of pennation or muscle thickness. Fiber length (decreased), angle of pennation (greater) and muscle thickness (greater) of most parts of the gastrocnemius and soleus muscles were significantly different in males and females. Leg length of males and females did not correlate to these architectural parameters.

In vivo diffusion tensor imaging of the human calf muscle

“…Figure 5d shows that the fibers of the soleus muscle have a complicated architecture and change directions along the SI direction. US and morphologic measurements of the soleus indicate that it is compartmentalized into a unipennate posterior group and a bipennate anterior group (22,26). Furthermore, three-dimensional structure and velocity maps from MRI have shown that the anterior soleus fibers are arranged radially around the median septum (27).…”

“…B-mode US is a noninvasive imaging modality that has been widely used to image muscle architecture (26,29,30). It is fast and allows real-time measurements of fiber lengths and pennation angles to be made even during isometric contraction (29,30).…”

Comparing human skeletal muscle architectural parameters of cadavers with in vivo ultrasonographic measurements

“…A Toshiba SSH-140A real time ultrasound scanner with 5 MHz or 7n5 MHz linear array transducer was used for the study (Leekam et al 1999 ;Chow et al 2000). Information was processed with the Agfa Impax System (Pax System).…”

Redundancy or heterogeneity in the electric activity of the biceps brachii muscle? Added value of PCA-processed multi-channel EMG muscle activation estimates in a parallel-fibered muscle

“…Recently, it was shown that the problem of electrode alignment can be overcome with principal component analysis (PCA), which was applied on multiple monopolar EMG channels and is thus unbiased with respect to the muscle fiber direction (Staudenmann et al, 2006). So far, PCA-processed monopolar multi-channel EMG has been applied on the triceps brachii, and triceps surae (Staudenmann et al, 2006(Staudenmann et al, , 2009a, both mainly pennate and architecturally complex muscles (Chow et al, 2000;Kawakami et al, 1993). A substantial improvement in muscle activation estimates was achieved with PCA as compared to multiple bipolar EMG using the same electrodes (Staudenmann et al, 2006(Staudenmann et al, , 2009a, suggesting that the misalignment of (multiple) bipolar EMG is a cause of errors in the estimation.…”