Anomalous attachment of the flexor digiti minimi muscle of the foot: An anatomical study with clinical implications

In human beings, the muscles of the sole of the foot are known to exhibit variations. During routine cadaveric dissection, an anomalous attachment of the flexor digiti minimi muscle was observed on both sides of a 55 year male cadaver. The flexor digiti minimi muscle had its usual origin from the plantar surface of base of the fifth metatarsal bone and the sheath of the peroneus longus muscle and had its insertion into the abductor digiti minimi muscle, as well as in to the medial and lateral sides of plantar surface of the base of distal phalanx of the fifth metatarsal bone. Some fibres of this muscle were also found to insert into plantar and deep transverse metatarsal ligaments. The attachment of the flexor digiti minimi muscle of the foot to the distal phalanx of the little toe (instead of the usual attachment into the proximal phalanx) is often regarded as a separate muscle i.e. the opponens digiti minimi. Distal attachment of the flexor digiti minimi muscle of the foot may also play a role in the biomechanics of the flexor digiti minimi muscle. The presence of such anomalous muscles may also be of academic and surgical interest in day to day medical practice.