Accessory soleus muscle: a case report and clinical applicability

Area of Science:

• Anatomy
• Human Anatomy
• Musculoskeletal System

Background:

• Anatomical variations in leg muscles are rare and infrequently documented.
• The accessory soleus muscle (ASM) is an uncommon muscular variation with a reported incidence of 0.5-6.0% in cadaveric studies.

Observation:

• During routine dissection, an accessory soleus muscle was discovered in the right lower limb of a male cadaver.
• The muscle measured 3 cm wide, 9 cm long, and 1 cm thick, exhibiting penniform fiber arrangement.

Findings:

• The accessory soleus muscle was situated in the posteromedial ankle, anterior to the Achilles tendon.
• It covered the tibial nerve and posterior tibial vessels, with its lower portion extending into the tarsal tunnel.

Implications:

• The anatomical position of the accessory soleus muscle within the tarsal tunnel poses a risk of neurovascular bundle compression.
• This compression could potentially lead to ischemic compartment syndrome, highlighting the clinical significance of this anatomical variation.