A Rare Variation of Plantar Interossei Muscles of the Foot - a Case Report

The variations in the attachment of plantar interossei might affect the gait of the individual and also raise questions about the function of this muscle at the tarsometatarsal joints. During routine dissection of the right lower limb, we encountered a unique variation in the attachment of plantar interossei. The first plantar interossei took origin from the lateral side of the base of the first metatarsal and inserted into the lateral side of the base of the proximal phalanx of the great toe. The second and third plantar interossei took origin from the medial surface of the base of the second and third metatarsals, respectively, and inserted into the medial side of the base of the proximal phalanges of the corresponding digits. The third and fourth intermetatarsal spaces were void, indicating the absence of these muscles from those spaces. The clinical significance of this variation has been discussed.