Variations in Dimensions and Attachments of the Plantaris Muscle

Abstract

Plantaris is a rudimentary muscle of the calf that is considered an accessory to the gastrocnemius. It has been harvested for use ranging from grafts in hand surgery (https://www.jhandsurg.org/article/S0363-5023(07)00773-3/abstract) to heart valve repair (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC152834/). It has been postulated as the source of tendinopathy of the Achilles tendon as well as the tendon of the tibialis posterior muscle (https://www.hindawi.com/journals/bmri/2018/9623579/). This study evaluates the plantaris muscle, its tendon, and attachments, in dissected cadavers from the Fall 2020 semester of the gross anatomy course at D'Youville College. Typically, the plantaris is a slim fusiform-shaped muscle that originates from the lateral supracondylar line of the femur and inserts medial to the Achilles tendon on the calcaneal tuberosity. Three variations of the orientation of the tendon insertion were discovered in this study. Equally common were attachment of the plantaris tendon medial to the Achilles tendon and attachment deep to the Achilles tendon. Also seen in a few specimens was attachment of the tendon to the crural fascia. The dimensions of the muscle, length and width of the tendon, and width of the tendon attachment were recorded and analyzed. Knowledge of the variations of the size and differences in location and width of the insertion of the plantaris tendon will aid in surgical procedures, in diagnosis of regional tendinopathy, and may be of importance in possible further research.