1. LUMC 2019
FOOT
Robert J. Frysztak, Ph.D.

2. Objectives
Recognize the major features and surface landmarks of the bones of the ankle and foot.
Describe the close relations of the blood vessels, nerves, ligaments and tendons which may be injured in fractures or dislocations at the ankle and in the foot.
Demonstrate the origin, course and branches of the major arteries that supply the foot.
Describe the origin, course and function of the common fibular and tibial nerves, and summarize the muscles that each supplies as well as their sensory distribution.
Describe the anatomy of the ankle joint. Explain the movements of flexion, extension, plantar flexion and dorsiflexion. Summarize the muscles responsible for these movements, their innervation, attachments and blood supply.
Describe the movements of inversion and eversion at the ankle, the muscles responsible, their innervation, blood supply and main attachments.
Describe the dermatomes of the foot.
Interpret standard diagnostic images of the lower limb.

3. * Bones of the Foot Plantar (Sole) Dorsal Phalanges Metatarsals
Tarsal Bones (7)
Talus: head (articulates with navicular), neck and body (articulates with tibia and fibula).
Calcaneus: transfers weight from talus to ground via the calcaneal tuberosity; articulates with talus superiorly, cuboid anteriorly; sustentaculum tali is a “shelf” on the medial surface that supports talus and creates passageway (groove) for flexor hallucis longus tendon; lateral surface has fibular trochlea and a groove for fibularis longus tendon.
Navicular: “little boat”; articulates with talus & cuneiforms
Cuboid: articulates with calcaneus posteriorly, 4th & 5th metatarsals anteriorly, 3rd cuneiform medially; groove for fibularis longus tendon.
Cuneiforms (medial, intermediate, lateral): wedge-shaped; articulate with 1st (medial), 2nd (intermediate), 3rd (lateral) metatarsals anteriorly, navicular posteriorly, each other intermedially.
Metatarsal Bones (5)
1st (medial, big toe) through 5th
Each metatarsal consists of base proximally, shaft, and head distally
5th metatarsal has styloid tuberosity projecting posterolaterally (fibularis longus tendon)
Phalanges (14)
Big toe: proximal & distal only
Other toes: proximal, intermediate & distal
Each phalanx consists of base proximally, shaft, and head distally
Tarsal Bones
Dorsal *

4. Bones of the Foot Lateral Medial
sustentaculum tali is a “shelf” on the medial surface that supports talus and creates passageway (groove) for flexor hallucis longus tendon; lateral surface has fibular trochlea and a groove for fibularis longus tendon.
Sustentaculum tali

5. Cutaneous Nerves Anterior Posterior Cutaneous branches:
Saphenous (femoral): medial malleolus and medial side of foot
Sural (sciatic): lateral malleolus and small portion of sole
Medial calcaneal (tibial): heel
Medial plantar (tibial): sole of foot; plantar surface of 3 ½ toes
Lateral plantar (tibial): lateral portion of sole; plantar surface of 1 ½ toes
Superficial fibular (fibular): dorsum of foot (except deep fibular area)
Deep fibular (fibular): dorsal surface between 1st & 2nd toes

6. Dermatomes
Anterior
Posterior * L4

7. Superficial Veins
Anterior
Posterior

8. Nerves
Dorsum of Foot
Ext. Hall. Brevis *

9. Dorsum of the Foot
Superficial Fibular Nerve: cutaneous to most of the dorsum of the foot except tips of toes.
Deep Fibular Nerve: 2 muscles (EHB, EDB) and sensory between 1st & 2nd toes. *
Anterior Tibial Artery: through interosseous membrane; changes name at ankle (talus) to become dorsalis pedis a.
Dorsalis Pedis Artery: continuation of anterior tibial a.
Medial & lateral tarsal aa.
Dorsal (superficial) arch
Deep plantar branch (anastamose with plantar arch * )
Dorsal metatarsal branches
Perforating branches (anastamose with plantar arch*) *

10. Dorsum of the Foot Innervated by the Deep Fibular Nerve
Hallucis Brevis
Extensor
Digitorum Brevis
Extensor

11. Plantar Aponeurosis & Sole of the Foot
Plantar Aponeurosis: thickened deep fascia of the sole, extending from the calcaneal tuberosity to end in 5 slips over the heads of the metatarsals, and into the flexor tendon sheaths.
Plantar Reflex: toes flex
(Babinski sign: hallux extends & toes abduct)
Cutaneous Nerves:
Saphenous: from femoral (L3-4) covers medial edge of foot.
Sural: from tibial & common fibular (S1-2) covers lateral edge of foot.
Tibial: medial calcaneal branch of tibial (L4-5) covers the heel of the foot.
Medial Plantar: from tibial (L4-5) covers the medial sole including the first 3½ toes onto the dorsal surface; follows medial plantar a.
Lateral Plantar: from tibial (S1-2) covers the lateral sole and the last 1½ toes onto the dorsal surface; follows lateral plantar a.

12. * A F A Plantar Surface of the Foot I Abductor hallucis
Flexor digitorum brevis – tendons split
Abductor digiti minimi
Layer 1: A F A
Abductor hallucis: medial plantar n; flex & abduct big toe
Flexor digitorum brevis: medial plantar n; middle phalanx of toes 2-5
Abductor digiti minimi: lateral plantar n; flex & abduct 5th toe F A A *

13. * 2M + 2T Plantar Surface of the Foot II Quadratus plantae
Lumbricales (4)
Tendon of flexor digitorum longus *
Tendon of flexor hallucis longus M
Layer 2: 2M + 2T (2 muscles, 2 tendons)
Quadratus plantae: lateral plantar n.; inserts into lateral border of flexor digitorum longus tendons; assists in flexion of toes 2-5
Lumbricales: 1st lumbrical innervated by medial plantar n.; 2nd thru 4th innervated by lateral plantar n.; flex proximal and extend distal phalanges (similar to hand)
Tendon of flexor digitorum longus
Tendon of flexor hallucis longus
T T M *

14. * F A F Plantar Surface of the Foot III Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis A
Layer 3: F A F
Flexor hallucis brevis: medial plantar n; 2 bellies; flexes metatarsophalangeal joint of 1st toe
Adductor hallucis: lateral plantar n; 2 heads (oblique & transverse); adducts 1st toe and helps maintain transverse arch
Flexor digiti minimi brevis: lateral plantar n; flexes metatarsophalangeal joint of 5th toe F F *

15. * 2M + 2T Plantar Surface of the Foot IV 3 PAD 4 DABS
Layer 4: 2M + 2T (2 muscles, 2 tendons)
Plantar interossei (PAD): lateral plantar n; adduct digits 3-5 toward midline (2nd toe); Unipennate
Dorsal interossei (DABS): lateral plantar n; abduct digits 2-4 from midline (2nd toe); Bipennate
Tendon of fibularis longus
Tendon of tibialis posterior
Plantar interossei (PAD)
Dorsal interossei (DABS)
Tendon of fibularis longus
Tendon of tibialis posterior *
Tibialis posterior tendon

16. * Layer IV: Interossei Dorsal Abductors Bipennate (2 heads)
Plantar Adductors
Unipennate (1 head) *

17. Muscles of the Plantar Surface of the Foot
1st Dorsal
Interosseus
Adductor
hallucis
Flexor
digiti
minimi
brevis
Lumbricals
1 -4
3rd Plantar
Interosseus
Flexor
hallucis
Flexor
Digitorum
Brevis
Abductor
Hallucis
Quadratus
Plantae
Abductor
Digiti
Minimi
Flexor
Digitorum
Longus
Layer 1 (A F A)
Layer 2 (2M + 2T)
Layer 3 (F A F)

18. * * Vessels of the Plantar Foot FIBULAR ARTERY POSTERIOR TIBIAL ARTERY
Posterior Tibial Artery: divides beneath origin of adductor halluces m. into medial & lateral plantar arteries.
Medial plantar: courses inferiorly to reach the medial border of the big toe.
Lateral Plantar Artery: courses laterally distal to calcaneus to form Plantar (deep) Arch
Receives perforating branches from dorsalis pedis a.
Plantar metatarsal branches
Plantar digital branches
Terminal branch anastomoses with superficial arch between 1st & 2nd metatarsals* * *

19. * Nerves of the Plantar Foot LAFF Lateral Plantar Medial Plantar
Lumbrical 1
Abductor hallucis
Flexor Dig. Brevis
Flexor Hallucis Brevis
Ext. Hall. Brevis
Tibial Nerve also divides beneath the adductor hallucis m. into medial and lateral plantar nerves.
Medial plantar supplies AbH, FDB, FHB & 1st Lumbrical (LAFF), and continues as cutaneous branches to medial 3½ toes.
Lateral plantar supplies QP & AbDM, then divides into a superficial (FDMB, 4th Int) and a deep branch (AdH, 1st – 3rd Int), then continues as cutaneous branches.
Abd. Dig. Minimi
Quad. Plantae
Add. Hallucis
Fl. Dig. Min. Brevis
All Interossei;
Lumbricals 2-4
Medial
Plantar
(LAFF) *

20. Question 1
As a first-year medical student, you are asked to demonstrate the location of the dorsalis pedis pulse. Which of the following landmarks would be a reliable guide for finding this artery?
Lateral to the extensor hallucis longus tendon
Medial to the fibularis longus and brevis tendons
Directly over the cuboid bone
Over the third metatarsal bone
Distal to the first proximal phalynx

21. Question 1
Lateral to the extensor hallucis longus tendon
Medial to the fibularis longus and brevis tendons
Directly over the cuboid bone
Over the third metatarsal bone
Distal to the first proximal phalynx
Lateral
Extensor hallucis longus tendon
The dorsalis pedis pulse can be reliably and most easily found just lateral to the extensor hallucis longus tendon (points the big toe up), where this artery can be palpated by pressing it against the underlying navicular or intermediate cuneiform bone.
Dorsalis pedis a.

22. Question 2
A 23 year old female spills a box of tacks while cleaning out her “junk drawer.” While cleaning them, she accidentally steps on one, which pierces the medial side of the sole of her foot at about the midpoint. The tack has impaled the flexor digitorum longus tendon, and damaged the adjacent nerve. Which one of the following muscles is most likely affected?
Quadratus plantae
Flexor digitorum brevis
Adductor hallucis
Plantar interossei
Abductor digiti minimi

23. Question 2 Medial plantar nerve: “LAFF” Lumbrical 1 Abductor Hallucis
Which one of the following muscles is most likely affected?
Quadratus plantae
Flexor digitorum brevis
Adductor hallucis
Plantar interossei
Abductor digiti minimi
Medial plantar nerve: “LAFF”
Lumbrical 1
Abductor Hallucis
Flexor Hallucis Brevis
Flexor Digitorum Brevis
Medial plantar nerve: “LAFF”

24. Arteries

25. Nerves Tibial Tibial SCIATIC (TIBIAL & FIBULAR ) FEMORAL OBTURATOR
Superior Gluteal n.
Inferior Gluteal n.
Sup. gemellus
Inf. gemellus
Tibial
Common Fibular
Tibial
Deep Fibular
Superficial
Medial Plantar
Lateral
Plantar
Ext. Hall. Brevis
LAFF
Abd.Dig.Min.; Quad. Pl.; Add.Hall.; Fl.Dig.Min.Br.;
All Interossei; Lumbricals 2-4

26. Nerve Injuries
Femoral: wasting of anterior thigh, leg drop (inability to extend leg when thigh is flexed), weakness in thigh flexion (loss of RF, Sar, Pect.); sensory loss anterior thigh & medial leg/foot
Obturator: wasting of medial thigh, loss of thigh adduction; sensory loss upper medial thigh
Superior Gluteal: Trendelenburg sign (pelvis tilts down on side opposite injury); no sensory loss
Inferior Gluteal: wasting of buttock, weakness in thigh extension; no sensory loss
Sciatic: wasting of all hamstrings and muscles of leg & foot;
sensory loss to back of thigh and leg, lateral leg and plantar foot
Common Fibular: foot-drop and loss of toe extension; sensory loss lateral leg and dorsum of foot
Tibial: loss of foot and toe flexion, loss of foot inversion, wasting of calf muscles; sensory loss on sole of foot and tips of toes *

28. Final Thoughts MY FOOT HURTS, DOCTOR.
OW! OW! QUIT KICKING! SEE, THAT’S WHY YOUR DUMB FOOT HURTS! STOP IT!