Extensor digitorum longus muscle

Zahra Sabahi and Assoc Prof Craig Hacking ◉ ◈ et al.

Extensor digitorum longus (EDL) is a thin muscle situated in the anterior leg lateral to extensor hallucis longus and extends the lateral four toes.

Summary

origin: upper two thirds of anterior shaft of fibula, superior portion of the anterior surface of the interosseous membrane, superior tibiofibular joint, anterior lateral condyle of tibia
insertion: dorsal aponeurosis on the dorsal surface of the proximal phalanges of the 2^nd, 3^rd, 4^th and 5^th toes. Each dorsal aponeurosis then divides into a central band and two lateral bands:
- the central band inserts into the base of the middle phalanx
- the lateral bands insert into the medial and lateral surfaces of the base of the distal phalanx
action: extends the lateral four toes, aids in dorsiflexion
arterial supply: anterior tibial artery
innervation: deep peroneal nerve (L5. S1)
key relationships:
- lateral to extensor hallucis longus
- shares a common tendon sheath with peroneus tertius
- superficial to the extensor digitorum brevis

Gross anatomy

The muscle divides into four distinct tendons above the ankle joint which descend deep to the superior extensor retinaculum. As these tendons pass deep to the inferior extensor retinaculum, they are enclosed in a common tendon sheath with peroneus tertius.

Quiz questions

References

Anatomy: Lower limb

Anatomy: Lower limb

skeleton of the lower limb
joints of the lower limb
- hip joint
  - ligaments
  - muscles
  - additional structures
    - hip joint capsule
    - zona orbicularis
    - iliotibial band
    - hip bursae
      - anterior
        iliopsoas bursa (iliopectineal bursa)
      - lateral
        
        subgluteal bursae
        
        greater trochanteric bursa (subgluteus maximus bursa)
        
        subgluteus medius bursa
        
        subgluteus minimus bursa
        
        gluteofemoral bursa
      - postero-inferior
        
        obturator externus bursa
        
        obturator internus bursa
        
        ischiogluteal bursa
  - ossification centers
- knee joint
- tibiofibular joints
  - proximal tibiofibular joint
  - distal tibiofibular syndesmosis
    - ligaments
      - anterior inferior tibiofibular ligament
        accessory anterior inferior tibiofibular ligament
      - posterior inferior tibiofibular ligament
- ankle joint
  - regional anatomy
    - medial ankle
    - lateral ankle
    - anterior ankle
  - ligaments
    - medial collateral (deltoid) ligament
      - superficial layer
        
        tibionavicular ligament
        
        tibiospring ligament
        
        tibiocalcaneal ligament
        
        superficial posterior tibiotalar ligament
      - deep layer
        
        anterior tibiotalar ligament
        
        deep posterior tibiotalar ligament
    - lateral collateral ligament
    - additional structures
    - ankle bursae
      - retrocalcaneal bursa
      - subcutaneous calcaneal bursa
  - ossification centers of the ankle
  - variants
    - ball and socket ankle joint
- foot joints
  - subtalar joint
    - articulations
      - talocalcaneal joint
    - ligaments
    - associated structures
  - mid-tarsal (Chopart) joint
    - talonavicular joint
    - calcaneocuboid joint
  - tarsometatarsal (Lisfranc) joint
    - ligaments
      - Lisfranc ligament
  - intermetatarsal joint
  - metatarsophalangeal joint
    - intermetatarsal bursa
  - interphalangeal joint
  - ossification centers
spaces of the lower limb
- adductor canal
- femoral sheath
  - femoral canal
    - femoral ring
- femoral triangle (contents mnemonic | boundaries mnemonic)
- foot subdivisions
- popliteal fossa (mnemonic)
- spring ligament recess
- tarsal tunnel (mnemonic)
- triangular space of cruciate ligaments
muscles of the lower limb
- muscles of the pelvic group
  - inner hip group
    - iliopsoas muscle
  - gluteal region
  - lateral rotator group
- muscles of the thigh
- muscles of the leg
  - anterior compartment of the leg
  - posterior compartments of the leg
    - superficial posterior compartment of the leg (calf)
      - triceps surae muscle
        
        medial and lateral heads of the gastrocnemius muscle
        
        soleus muscle
        accessory soleus muscle
      - plantaris muscle
      - calcaneal tendon
    - deep posterior compartment of the leg
  - lateral compartment of the leg
    - peroneus brevis muscle
    - peroneus longus muscle
- muscles of the foot
  - dorsal muscles
    - extensor hallucis brevis muscle
    - extensor digitorum brevis muscle
  - plantar muscles
    - 1st layer
    - 2nd layer
      - quadratus plantae muscle
      - lumbrical muscles
    - 3rd layer
    - 4th layer
      - dorsal interossei muscles
      - plantar interossei muscles
- accessory muscles
  - accessory peroneal muscles
vascular supply of the lower limb
- arterial supply of the lower limb
- venous drainage of the lower limb
  - deep system
    - common femoral vein
      - femoral vein
        
        deep femoral vein
        
        popliteal vein
        
        peroneal vein
        
        posterior tibial vein
        
        anterior tibial vein
  - superficial system
  - venous drainage of the foot
innervation of the lower limb
- lumbar plexus (mnemonic)
  - femoral nerve
    - saphenous nerve
  - obturator nerve
- sacral plexus
  - sciatic nerve (motor distribution)
    - common peroneal nerve
      - superficial peroneal nerve
      - deep peroneal nerve
    - tibial nerve
lymphatic system of the lower limb
- lymphatic pathways
  - anteromedial group
  - anterolateral group
  - posteromedial group
  - posterolateral group
- lower limb lymph nodes
  - inguinal lymph nodes
    - superficial inguinal lymph nodes
    - deep inguinal lymph nodes
  - popliteal lymph nodes

Article information

rID: 40283

System: Musculoskeletal

Section: Anatomy

Synonyms or Alternate Spellings:

Extensor digitorum longus (EDL)
EDL
Extensor digitorum longus

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