Posterior Leg and Plantar Foot

Superficial Group

Deep Group

Superficial : Gastrocnemius, Soleus, Plantaris = Powerful Plantarflexion (pushing off when walking/running)

Deep: Tibialis Posterior, Flexor Digitorium Longus, Flexor Hallucis Longus, Popliteus = foot control and stability (Tom Dick and Harry)

Triceps Surae Powehouse

Gastrocnemius and soleus responsible for most of push off when walking/jumping

Insert via Achilles tendon - strongest tendon in the body

Test by plantarflexing against resistance (stand on toes)

What is key for maintaining medial longitudinal arch of foot, preventing flatfoot. Dysfunction can lead to gait instability and overpronation

Tibialis Posterior

Tom Dick and Nervous Harry

Tibialis Posterior

Flexor Digitorium Longus

Posterior Tibial Artery

Tibial Nerve

Flexor Hallucis Longus

Motor Innervation

Foot Inversion:

Plantarflexion:

Toe Flex:

Calcaneal (Achilles; ankle jerk):

Foot Inversion: L4,L5

Plantarflexion: S1,S2

Toe Flex: S2,S3

Calcaneal (Achilles; ankle jerk): S1/S2

Severance of Tibial Nerve causes

Paralysis of flexor muscles in leg (inability to plantar flex) and intrinsic muscles of sole of foot (inability to flex toes)

Layer 1 Plantar Surface of Foot

Abductor digiti minimi

Flexor digitorum brevis

Abductor hallucis

Layer 2 Muscles and Tendons

Quadratus Plantae

Lumbricals

Tendon of flexor hallucis longus

Tendon of flexor digitorium longus

Layer 3

Flexor Hallucis Brevis

Flexor Digiti Minimi Brevis

Adductor Hallucis

Also visible: FHL tendon running between two heads of flexor hallucis brevis. Arching of lateral plantar artery (deep plantar arch) and plantar metatarsal arteries

Layer 4

Plantar Interosseous

Dorsal Interosseous

Tendon of Fibularis Longus

Tendon of Tibialis Posterior

Toe Movement

Big Toe:

2-4:

5:

Big Toe: Flexor Hallucis Longus, Flexor Hallucis Brevis, Abductor Hallucis, Adductor Hallucis (transverse and oblique)

2-4: Flexor Digitorium Longus, Flexor Digitorium Brevis, Quadratus Plantae (flexor assist), Lumbricals (flexes)

5: Flexor digitorium longus, flexor digitorium brevis, quadratus plantae (flexor assist), lumbrical (flexes), flexor digiti minimi brevis, abductor digiti minimi

Plantar Foot Motor Innervation

LAFF muscles

First lumbrical (to second digit)

Abductor hallucis

Flexor Digitorium Brevis

Flexor Hallucis Brevis

Posterior Calf and Lateral Foot Cutaneous Innervation:

Lateral Calf Innervation:

Medial Calf Innervation:

Medial and Mid Sole:

Lateral Sole:

Posterior Calf and Lateral Foot Cutaneous Innervation: Medial sural cutaneous branch (from tibial nerve) joined by sural communicating branch of common fibular nerve to form sural nerve

Lateral Calf: Lateral sural cutaneous (from common fibular nerve)

Medial Calf: Saphenous Nerve (from femoral nerve)

Medial and Mid Sole: Medial Plantar Nerve (from tibial)

Lateral Sole: Lateral Plantar Nerve (from tibial)