Department of Anatomy, Guru Gobind Singh Medical College, Baba Farid University of Health Sciences, Faridkot, Punjab, India
The superficial flexors gastrocnemius, soleus and plantaris form the bulk of calf. The plantaris muscle is extremely variable in its origin.
During routine dissection (for undergraduate medical students) of the lower limbs of an adult male cadaver, we observed an accessory tendinous slip of origin of this muscle (from the deep surface of the gastrocnemius muscle) in addition to the one (from the lower part of the lateral supracondylar ridge of femur and the adjoining oblique popliteal ligament of the knee joint) described in the standard textbooks of anatomy. In addition to this variation, it was also seen that the plantaris was entrapped between the tibial nerve and the nerve to soleus (branch of nerve to gastrocnemius) in the popliteal fossa.
Despite being a vestigial muscle in human beings, the awareness of its anatomical variations is important, as is evident from the fact that its tendon grafts have been successfully used in the reconstruction of anterior tibiofibular and calcaneofibular ligaments, for flexor tendon replacement in hand and for atrioventricular valve repair. It has been established bymagnetic resonance imaging scan and ultrasonography that injuries to this muscle can occur in isolation (tennis leg). Hence, its knowledge is of significance for the clinicians and physiotherapists diagnosing and managing muscle tears, surgeons performing tendon transfer operations and radiologists interpreting MRI scans. Keeping in mind the clinical relevance of the anomalies recorded in our case report, an attempt has been made to explain them in the light of the phylogenetic and ontogenic backgrounds.
Superficial flexors, Tendinous slip, Supracondylar ridge, Oblique popliteal ligament, Tibial nerve, Tendon grafts
