Soleus Accessorius: An Uncommon Anatomic Variant of the Calf Muscle

Anatomical variants like the soleus accessorius underscores the incredible diversity within the human body. It serves as a reminder that healthcare professionals should remain vigilant, especially in cases where unexpected structures or variations are encountered during diagnosis or treatment.

Sagittal T2w and T1w – MRI 0.3 Tesla

The soleus accessorius, also known as accessory soleus, is a relatively rare anatomical variant of the calf muscle, the soleus. The soleus muscle is one of the two major muscles in the calf, with the other being the gastrocnemius. The soleus accessorius, when present, is typically an additional muscle belly or slip located adjacent to the primary soleus muscle.

The presence of a soleus accessorius can have clinical significance in several ways:

1. Misdiagnosis: An accessory soleus can be mistaken for a soft tissue mass or other pathology in medical imaging studies, potentially leading to misdiagnosis and unnecessary medical interventions.

2. Functional Impact: In some cases, the soleus accessorius can be associated with altered biomechanics and may contribute to conditions like posterior compartment syndrome, leading to pain and discomfort in the lower leg.

3. Surgical Considerations: Surgeons and orthopedic specialists need to be aware of a soleus accessorius when performing procedures on the calf muscles to avoid accidental damage or complications.

Dynamic Ultrasound Study of the Quadriceps Muscle

It is always interesting to study the functionality of the muscles in real training conditions; in this period I am testing the usefulness of the ultrasound study performed during walking and running on the treadmill.

What is evident is a difference from the conventional examination in terms of shape and dimensions of the various muscle components, which work as a single entity.

In this study, I’m using a MyLab 9 ultrasound device from Esaote, with an external accessory called Probe-Fix which provides lengthy and stable fixation of the probe to the body.

In the video, you can see the quadriceps muscle study, but I’m also testing the hamstrings in the same conditions and during other physical activities, such as squatting and jumping.

Enjoy the video and stay tuned.