Muscles That Move the Feet and Toes

Similar to the thigh muscles, the muscles of the leg are divided by deep fascia into compartments, although the leg has three: anterior, lateral, and posterior.

Table 11.18a: Muscles That Move the Feet and Toes (Anterior Compartment of Leg)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Tibialis anterior	Raises the sole of the foot off the ground, as when preparing to foot-tap; bends the inside of the foot upwards, as when catching your balance while falling laterally toward the opposite side as the balancing foot	Foot	Dorsiflexion; inversion	Lateral condyle and upper tibial shaft; interosseous membrane	Interior surface of medial cuneiform; First metatarsal bone
Extensor hallucis longus	Raises the sole of the foot off the ground, as when preparing to foot-tap; extends the big toe	Foot; big toe	Foot: dorsiflexion; big toe: extension	Anteromedial fibula shaft; interosseous membrane	Distal phalanx of big toe
Extensor digitorum longus	Raises the sole of the foot off the ground, as when preparing to foot-tap; extends toes	Foot; toes 2-5	Foot: dorsiflexion; big toe: extension	Lateral condyle of tibia; proximal portion of fibula; interosseous membrane	Middle and distal phalanges of toes 2-5

Table 11.18b: Muscles That Move the Feet and Toes (Lateral Compartment of Leg)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Fibularis longus	Lowers the sole of the foot to the ground, as when foot-tapping or jumping; bends the inside of the foot downward, as when catching your balance while falling laterally toward the same side as the balancing foot	Foot	Plantar flexion and eversion	Upper portion of lateral fibula	First metatarsal; medial cuneiform
Fibularis (peroneus) brevis	Lowers the sole of the foot to the ground, as when foot-tapping or jumping; bends the inside of the foot downward, as when catching your balance while falling laterally toward the same side as the balancing foot	Foot	Plantar flexion and eversion	Distal fibula shaft	Proximal end of fifth metatarsal

Table 11.18c: Muscles That Move the Feet and Toes (Posterior Compartment of Leg: Superficial Muscles)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Gastrocnemius	Lowers the sole of the foot to the ground, as when foot-tapping or jumping; assists in moving the back of the lower legs up and back toward the buttocks	Foot; tibia/fibula	Foot: plantar flexion; tibia/fibula: flexion	Medial and lateral condyles of femur	Posterior calcaneus
Soleus	Lowers the sole of the foot to the ground, as when foot-tapping or jumping; maintains posture while walking	Foot	Plantar flexion	Superior tibia; fibula; interosseous membrane	Posterior calcaneus
Plantaris	Lowers the sole of the foot to the ground, as when foot-tapping or jumping; assists in moving the back of the lower legs up and back toward the buttocks	Foot; tibia/fibula	Foot: plantar flexion; tibia/fibula: flexion	Posterior femur above lateral condyle	Calcaneus or calcaneus tendon
Tibialis posterior	Lowers the sole of the foot to the ground, as when foot-tapping or jumping	Foot	Plantar flexion	Superior tibia and fibula; interosseous membrane	Several tarsal and metatarsals 2-4

Table 11.18d: Muscles That Move the Feet and Toes (Posterior Compartment of Leg: Deep Muscles)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Popliteus	Moves the back of the lower legs up and back toward the buttocks; assists in the rotation of the leg at the knee and thigh	Tibia/fibula	Tibia/fibula: flexion thigh and lower leg: medial and lateral rotation	Lateral condyle of femur; lateral meniscus	Proximal tibia
Flexor digitorum longus	Lowers the sole of the foot to the ground, as when foot-tapping or jumping; bends the inside of the foot upward and flexes toes	Foot; toes 2-5	Foot: plantar flexion and inversion toes: flexion	Posterior tibia	Distal phalanges of toes 2-5
Flexor hallucis longus	Flexes the big toe	Big toe; foot	Big toe: flexion foot: plantar flexion	Midshaft of fibula; interosseous membrane	Distal phalanx of big toe

The muscles in the anterior compartment of the leg all contribute to dorsiflexion: the tibialis anterior, a long and thick muscle on the lateral surface of the tibia, the extensor hallucis longus, deep under it, and the extensor digitorum longus, lateral to it. The fibularis tertius, a small muscle that originates on the anterior surface of the fibula, is associated with the extensor digitorum longus and sometimes fused to it, but is not present in all people. Thick bands of connective tissue called the superior extensor retinaculum (transverse ligament of the ankle) and the inferior extensor retinaculum, hold the tendons of these muscles in place during dorsiflexion.

The lateral compartment of the leg includes two muscles which contribute to eversion and plantar flexion: the fibularis longus (peroneus longus) and the fibularis brevis (peroneus brevis). The superficial muscles in the posterior compartment of the leg all insert onto the calcaneal tendon (Achilles tendon), a strong tendon that inserts into the calcaneal bone of the ankle, all contribute to plantar flexion. The muscles in this compartment are large and strong and keep humans upright. The most superficial and visible muscle of the calf is the gastrocnemius. Deep to the gastrocnemius is the wide, flat soleus. The plantaris runs obliquely between the two; some people may have two of these muscles, whereas no plantaris is observed in about seven percent of other cadaver dissections. The plantaris tendon is a desirable substitute for the fascia lata in hernia repair, tendon transplants, and repair of ligaments. There are four deep muscles in the posterior compartment of the leg as well: the popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior all contribute to plantar flexion or inversion of the foot.

The foot also has intrinsic muscles, which originate and insert within it (similar to the intrinsic muscles of the hand). These muscles primarily provide support for the foot and its arch, and contribute to movements of the toes (Figure 11.7.3 and Table 11.19a). The principal support for the longitudinal arch of the foot is a deep fascia called plantar aponeurosis, which runs from the calcaneus bone to the toes (inflammation of this tissue is the cause of “plantar fasciitis,” which can affect runners. The intrinsic muscles of the foot include the extensor digitorum brevis on the dorsal aspect and a plantar group, which consists of four layers.

Table 11.19a: Intrinsic Muscles in the Foot (Dorsal Group)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Extensor digitorum brevis	Extends toes 2-5	Toes 2-5	Extension	Calcaneus; extensor retinaculum	Base of proximal phalanx of big toe; extensor expansions on toes 2-5

Table 11.19b: Intrinsic Muscles in the Foot (Plantar Group: Layer 1)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Abductor hallucis	Abducts and flexes big toe	Big toe	Abduction; flexion	Calcaneal tuberosity; flexor retinaculum	Proximal phalanx of big toe
Flexor digitorum brevis	Flexes toes 2-4	Middle toes	Flexion	Calcaneal tuberosity	Middle phalanx of toes 2-4
Abductor digit minimi	Abducts and flexes small toe	Toe 5	Abduction; flexion	Calcaneal tuberosity	Proximal phalanx of little toe

Table 11.19c: Intrinsic Muscles in the Foot (Plantar Group: Layer 2)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Quadratus plantae	Assists in flexing toes 2-5	Toes 2-5	Flexion	Medial and lateral sides of calcaneus	Tendon of flexor digitorum longus
Lumbricals	Extends toes 2-5 at the interphalangeal joints; flexes the small toes at the metatarsophalangeal joints	Toes 2-5	Extension flexion	Tendons of flexor digitorum longus	Meidal side of proximal phalanx of toes 2-5

Table 11.19d: Intrinsic Muscles in the Foot (Plantar Group: Layer 3)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Flexor hallucis	Flexes big toe	Big toe	Flexion	Lateral cuneiform; cuboid bones	Base of proximal phalanx of big toe
Adductor hallucis	Adducts and flexes big toe	Big toe	Abduction; flexion	Bases of metatarsals 2-4; fibularis longus tendon sheath; ligament across metatarsophalangeal joints	Base of proximal phalanx of big toe
Flexor digiti minimi brevis	Flexes small toe	Little toe	Flexion	base of metatarsal 5; tendon sheath of fibularis longus	Base of proximal phalanx of big toe

Table 11.19e: Intrinsic Muscles in the Foot (Plantar Group: Layer 4)

Prime Mover	Movement	Target	Target Movement Direction	Origin	Insertion
Dorsal interossei	Abducts and flexes middle toes at metatarsophalangeal joints; extends middle toes at interphalangeal joints	Middle toes	Abduction; flexion; extension	Side of metatarsals	Both sides of toe 2; for each other toe, extensor expansion over first phalanx on side opposite toe 2
Plantar interossei	Abducts toes 3-5; flexes proximal phalanges and extends distal phalanges	Small toes	Abduction; flexion; extension	Side of each metatarsal that faces metatarsal 2 (absent from metatarsal 2)	Extensor expansion on first phalanx of each toe (except to 2) on side facing toe 2