Unilateral Absence of Plantaris muscle in Ethiopian Cadavers – a case report

Plantaris is the largest muscle in mammals other than primates. It runs alongside the gastrosoleus complex, and continues along the medial aspect of the Achilles tendon (AT) before inserting onto the greater tuberosity of the calcaneus. The plantaris muscle is vestigial in human beings and has much clinical importance. It is known to present several anatomical variations in terms of its occurrence, origin, course, relation with surrounding neurovascular structures and insertion. It may be absent unilaterally or bilaterally. The plantaris muscle is absent in 7–10% of the human population. Two such variations were observed unilaterally in the present report in which absence of the right plantaris muscle were seen in the right lower limb of the two cadavers. Despite its vestigial nature, injury to plantaris muscle can present a diagnostic challenge among clinicians and radiologists. Surgical importance of the muscle lies in successful use of its tendon for reconstructive surgery. Therefore, Knowledge of anatomical variations of the plantaris muscle is important for physiotherapists, plastic surgeons performing tendon transfer operations, clinicians diagnosing muscle tears and radiologists interpreting MRI scans.