Anatomy of the foot Flashcards
What is different about the bones in the big toe?
There is only a proximal and distal phalanx while the other bones have a proximal, medial, and distal
What bones make up the hind foot?
- Calcaneus
2. Talus
What bones make up the mid foot?
- Cuneiform bones = lateral intermediate, and medial
- Cuboid bone
- Navicular
What bones make up the fore foot?
- Phalanges
2. Metatarsals
What bones make up the ball of the foot?
- Sesamoid of 1st metatarsal
2. Head of 2nd metatarsal
What attaches to the groove for peroneus longus?
Peroneus longus tendon attaches here and goes across the foot to attach to the medial and intermediate cuneiform
Characteristics of the dorsal surface of the foot
- Deep fascia of the foot that is continuous with the crural fascia of the leg
- Deep fascia also goes to the plantar surface of the foot
- Inferior extensor retinaculum
Inferior extensor retinaculum
- Looks like a Y laying on its side
- Consists of 3 parts:
- stem
- superomedial limb- anterior surface of medial malleolus
- inferomedial lumb- attahes by blending with the plantar fascia
What cutaneous nerves supply the foot?
- Saphenous nerve
- Lateral dorsal cutaneous nerve
- Superficial peroneal nerve
- Deep peroneal nerve
What part of the foot does the saphenous nerve innervate?
Medial side down to the 1st metatarsal
What nerve does the lateral cutaneous branch come from?
Continuation of the sural nerve
What does the superficial peroneal nerve branch to?
Medial and intermediate dorsal cutaneous nerves
What part of the foot does the deep peroneal nerve innervate?
Supplies skin between the 1st and 2nd toes
What is the only intrinsic muscle of the foot?
Extensor digitorum brevis
What are the tendons in the foot?
- Extensor digitorum longus tendon
- Extensor hallucis longus tendon
- Extensor hallucis brevis
Extensor Digitorum longus tendon
One tendon for each of the lateral 4 toes
Where does the extensor hallucis longus attach?
1st toe only
Describe the extensor hallucis brevis tendon
Goes to the 1st toe
Tendon of extensor digitorum brevis
What is the nerve supply to the extensor digitorum brevis muscle?
Deep peroneal nerve
Describe the extensor digitorum brevis
Only intrinsic muscle of the dorsum foot
Extends toes 2-4
What does artery supplies the foot but changes names once it reaches the foot?
Anterior tibial artery which becomes the dorsalis pedis and branches to supply the whole foot
What are the branches of the dorsalis pedis artery?
- lateral tarsal
- Medial tarsal
- arcuate branch gives anterior perforating arteries
- deep plantar artery
- 1st dorsal metatarsal
What are the 2 terminal branches of the dorsal pedis artery?
- Deep plantar artery
2. 1st dorsal metatarsal artery
What forms the dorsal venous arch?
Tributaries of dorsal digital veins –> dorsal metatarsal veins –> medial marginal vein
What does the lateral marginal vein drain into?
Small saphenous vein
What are the plantar surface of the foot cutaneous nerves?
- Saphenous nerve
- Lateral dorsal cutaneous nerve
- Calcaneal branches
- Medial plantar nerve
- Lateral plantar nerve
What is the lateral dorsal nerve a continuation of from the leg?
Sural nerve
What area does the saphenous nerve innervate?
- Plantar and dorsal side of the foot
2. Front of the leg
What area does the medial plantar nerve innervate?
- Supplies medial 3 1/2 digits
What area does the lateral plantar nerve innervate?
- Lateral 1 1/2 digits
What are the contents of the deep fascia in the plantar foot?
- Flexor retinaculum
2. Plantar aponeurosis
Flexor retinaculum
- Gateway to the foot
- Tibialis posterior (Tom)
- Flexor digitorum (Dick)
- Flexor hallucis (Harry)
Plantar aponeurosis
- Supports longitudinal arches of foot
- Extends from calcaneous to toes
- Divides foot into 3 compartments
How many layers of muscles are in the plantar foot?
4
What muscles are in the first layer?
- Abductor hallucis
- Flexor digitorum brevis
- Abdcutor digiti minimi
What is the action of the 1st layer of muscles?
Flexors of the foot
Abductor Hallucis O and I
O: tuberosity of calcaneus
I: base of 1st proximal phalanx
Flexor digitorum brevis O and I
O: Tuberosity of calcaneous and part of plantar aponeurosis
I: Middle phalanx of lateral 4 toes
Abductor digiti minimi O and I
O: Tuberosity of calcaneous
I: base of 5th proximal phalanx
What are the muscles in the second layer?
2 muscles and 2 tendons
- Flexor digitorum longus tendon
- Flexor hallucis longus tendon
- Quadratus plantae
- Lumbrical muscles
What are the lumbricals a tendon to?
Flexor digitorum longus
What are the muscle in the 3rd layer?
- Peroneus longus tendon
- Tibialis posterior tendon
- Plantar interossei muscles (3)
- Dorsal interossei muscles (4)
Describe the plantar interossei muscles
- Not one on the big toe or 2nd toe
- 2nd toe is the central toe ergo it can’t a-dduct to itself
- big toe has the adductor hallucis
Describe the Dorsal interossi muscles
- 2nd toe has 2 of these muscles
- A-Bducttor muscles
- 1st and baby toe don’t have one
What are the branches from the tibial nerve in the foot?
- Medial calcaneal which branches into the next 2
- Medial plantar nerve
- Lateral plantar nerve
What muscles does the medial plantar nerve innervate?
- abductor hallucis
- Flexor digitorum brevis
- Flexor hallucis brevis
- 1st lumbrical
Describe the medial plantar nerve
- Between the 1st and 2nd layer of muscles
2. divides into 3 common plantar digital nerves which give rise to 2 proper digital nerves
Describe the lateral plantar nerve
- Branches to 4th common plantar digital nerve
- Provides cutaneous branches to lateral 1 1/2 digits
- Provides motor branches to rest of intrinsic muscles
