Multiple Heads of Gastrocnemius with Bipennate Fiber Arrangement-A Clinically Significant Variation

Abstract

It is common to have additional muscles or muscle slips in the extremities. Some of them may compress the nerves and vessels or restrict the movements, while others may enhance the muscular activity. However, a small number of them may go unnoticed. Knowledge of such variant muscles becomes important for plastic surgeons while performing various reconstructive surgeries and for clinicians while managing the pain. A case of multiple heads of gastrocnemius muscle was observed during routine dissection of the right lower limb of about 70-year-old male cadaver. It was observed that the medial head of gastrocnemius was attached to the femur with 3 thick heads and lateral head was arising from the lateral condyle of femur by 3 thick heads. All the heads of the muscles remained separate till they formed tendocalcaneus. Some of these heads showed bipinnate fiber arrangement. All the heads were innervated by the branches of tibial nerve. As the muscle heads passed down from their origin, they entrapped the sural nerve and sural nerve was seen emerging at the beginning of tendocalcaneus. Further, detailed literature and the clinical and surgical importance of the case are discussed.

Keywords

• bipennate gastrocnemius
• calf muscles
• tendocalcaneus
• variations