Plantar Aponeurosis: Anatomy

The plantar aponeurosis (plantar fascia) is composed of central, medial, and lateral segments. The base is attached to the calcaneus and has fibers continuous with those of the Achilles tendon.

• Medial segment (purple): Arises from the central segment and attaches to the inferior portion of the abductor hallucis muscle.
• Central segment (tan): The thickest component. Its proximal attachment is to the posterior aspect of the medial calcaneal tuberosity (posterior to the origin of the flexor digitorum brevis tendon). Its distal attachments are at the level of the metatarsophalangeal joints, dividing into five pairs of superficial and deep fasicles. The deep branches (blue) insert onto the metatarsophalangeal joints. The superficial branches bifurcate into sagittal septa, which attach onto the plantar plates (red), interosseous ligament, and deep transverse metatarsal ligaments of the 2nd through 5th digits and the plantar plate and sesamoid bones (white) of the great toe.
• Lateral segment (green): Attaches proximally to the lateral aspect of the medial process of the calcaneal tuberosity and is continuous medially with the central segment. Distally, it has a medial band inserts onto the plantar plate of the fourth and sometimes third metatarsophalangeal joints, and a lateral band that attaches to the base of the fifth metatarsal.

References

Moraes do Carmo CC, Fonseca de Almeida Melão LI, Valle de Lemos Weber MF, Trudell D, Resnick D. Anatomical features of plantar aponeurosis: cadaveric study using ultrasonography and magnetic resonance imaging. Skeletal Radiol. 2008 Oct;37(10):929-35.