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Third toe

The third toe (also called the middle toe) is the central digit of the foot, positioned between the second and fourth toes. It plays a key role in balance, propulsion, and weight distribution during gait. Like the other lesser toes, it consists of three phalanges — proximal, middle, and distal — connected by interphalangeal joints that permit flexion and extension.

The third toe is stabilized by a complex network of bones, ligaments, tendons, and intrinsic muscles, which together maintain digital alignment and aid in locomotion. It is supplied by digital branches of the plantar and dorsal arteries and nerves, and is a common site for callosities, deformities (hammer toe, claw toe), and flexor/extensor tendon injuries.

Synonyms

  • Middle toe

  • Third digit of foot

  • Central lesser toe

Osteology

  • Bones: Proximal phalanx, middle phalanx, and distal phalanx

  • Each phalanx consists of a base, shaft, and head

  • The proximal phalanx articulates with the third metatarsal bone at the metatarsophalangeal (MTP) joint

  • The middle and distal phalanges form the proximal and distal interphalangeal joints (PIP and DIP)

Joints and Ligaments

  • Metatarsophalangeal (MTP) Joint: Between third metatarsal head and proximal phalanx base; supported by plantar plate, collateral ligaments, and joint capsule

  • Proximal Interphalangeal (PIP) Joint: Between proximal and middle phalanges

  • Distal Interphalangeal (DIP) Joint: Between middle and distal phalanges

  • Collateral ligaments: On medial and lateral sides of each joint for stability

  • Plantar plate: Thick fibrocartilaginous structure reinforcing plantar aspect of MTP joint

Tendons and Muscles

  • Flexors:

    • Flexor digitorum longus (FDL): Inserts on distal phalanx; flexes all joints of the toe

    • Flexor digitorum brevis (FDB): Inserts on middle phalanx; flexes PIP joint

  • Extensors:

    • Extensor digitorum longus (EDL): Inserts on distal phalanx via dorsal expansion; extends all joints

    • Extensor digitorum brevis (EDB): Assists EDL at MTP joint

  • Intrinsic muscles:

    • Lumbrical: Flexes MTP joint and extends PIP/DIP via dorsal expansion

    • Interossei: Provide stability, abduction/adduction of the toe at MTP joint

Relations

  • Superiorly: Dorsal tendons of EDL and EDB

  • Inferiorly: Plantar tendons of FDL and FDB with digital neurovascular bundles

  • Laterally: Second and fourth toes

  • Medially: Adjacent intermetatarsal space and interosseous muscles

Nerve Supply

  • Plantar digital nerves from the medial and lateral plantar nerves (branches of tibial nerve)

  • Dorsal digital nerves from the superficial peroneal nerve supply dorsal skin

Arterial Supply

  • Plantar digital arteries from the plantar metatarsal arteries (branch of lateral plantar artery)

  • Dorsal digital arteries from dorsal metatarsal arteries (branch of dorsalis pedis artery)

Venous Drainage

  • Plantar venous plexus drains into medial and lateral plantar veins

  • Dorsal digital veins drain into dorsal venous arch and great/small saphenous veins

Function

  • Flexion/extension: Enables push-off during gait

  • Balance: Stabilizes forefoot during stance and propulsion

  • Shock absorption: Distributes load during walking and running

  • Fine motor control: Aids in grasp and adjustment of balance on uneven surfaces

Clinical Significance

  • Deformities: Hammer toe, claw toe, or mallet toe from tendon imbalance or footwear pressure

  • Trauma: Fractures of phalanges, dislocations, or plantar plate rupture

  • Tendon disorders: FDL/FDB tendinopathy, EDL tears, lumbrical strain

  • Morton’s neuroma: Can radiate pain to the third toe from adjacent intermetatarsal space

  • Circulatory disorders: Ischemic or diabetic ulceration due to distal vascular compromise

  • Postoperative importance: Landmark in digital deformity correction and tendon release surgeries

MRI Appearance

  • T1-weighted images:

    • Muscles: Intermediate signal intensity with visible fascicular texture

    • Tendons: Low signal (dark linear bands)

    • Cortical bone: Very low signal; marrow shows intermediate signal

    • Fat planes: Bright

    • Pathology: Bone marrow edema or tendon tear shows focal high/intermediate signal

  • T2-weighted images:

    • Muscles: Intermediate-to-low signal, darker than on T1

    • Tendons: Very low signal; tears show hyperintense gaps

    • Joint effusion or edema: Bright hyperintensity around PIP/DIP joints

    • Fractures or osteochondral injury: Hyperintense marrow edema adjacent to fracture line

  • STIR:

    • Normal muscle: intermediate-to-dark signal

    • Pathology (strain, inflammation, infection): bright hyperintensity

    • Useful for detecting subtle soft-tissue edema, bone marrow edema, or osteomyelitis

  • Proton Density Fat-Saturated (PD FS):

    • Normal muscle: intermediate-to-dark

    • Pathologic areas (tendinitis, joint effusion, plantar plate injury): bright signal intensity

    • Highlights peritendinous fluid, ligament tears, and capsular inflammation

  • T1 Fat-Sat Post-Contrast:

    • Normal muscle: mild uniform enhancement

    • Inflammation or infection: strong focal or diffuse enhancement

    • Abscess or sinus: rim enhancement with central low-signal cavity

CT Appearance

Non-Contrast CT:

  • Bones: Clearly delineated; cortical bone dense with visible trabecular detail

  • Soft tissues: Homogeneous, moderate density; tendons visible as linear strands

  • Fractures: Visible as cortical disruption or lucent lines

  • Degenerative changes: Osteophytes, subchondral sclerosis, or joint space narrowing

Post-Contrast CT (standard):

  • Muscle: Homogeneous enhancement

  • Inflamed soft tissues: Show focal enhancement

  • Osteomyelitis or infection: Cortical irregularity with surrounding soft-tissue enhancement

  • Excellent for evaluating bony injury, sesamoid fractures, or postoperative changes

MRI image

Third toe of foot axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

CT image

third toe CT coronal image