1. FOOT IN 30 QUESTIONS Exam of the Lower Extremities
From A Practical Guide to Clinical Medicine
University of California, San Diego
FOOT
IN 30 QUESTIONS
Kaan Yücel M.D., Ph.D.

2. INTRODUCTION TO FOOT Region of the lower limb distal to ankle joint
Subdivided into
Ankle
Metatarsus
Digits
Superior surface (dorsum of foot) Inferior surface (sole)

3. INTRODUCTION TO FOOT Body's point of contact with the ground
Provides a stable platform for upright stance.
Supports the body weight and provides leverage for walking and running.
Unique -constructed in the form of arches, adapt its shape to uneven surfaces.
Serves as a resilient spring to absorb shocks, such as in jumping.

4. SKIN & SUBCUTANEOUS TISSUE
IN 10 QUESTIONS

5. The subcutaneous tissue is loose deep to the dorsal skin
1…skin of the foot
Skin of the dorsum of the foot thinner and less sensitive than that of the sole
The subcutaneous tissue is loose deep to the dorsal skin
Edema most marked on the dorsal skin
especially anterior to and around the medial malleolus
Entire sole is sensitive (“ticklish”), especially the thinner-skinned area underlying the arch of the foot.
Neurosci Res Dec;68(4):285-9.
Neurogenesis in the dentate gyrus of the rat hippocampus enhanced by tickling stimulation with positive emotion.
Ticklish?
gargalesis

6. 2. Deep fascia of the foot & Plantar fascia
Thin where it is continuous proximally with the inferior extensor retinaculum.
Over the lateral and posterior aspects of the foot continuous with the plantar fascia, the deep fascia of the sole.
Plantar fascia holds the parts of the foot together, helps protect the sole from injury, and helps support the longitudinal arches of the foot.

7. 3. Compartments by the deep fascia Midfoot and forefoot
Medial compartment of the sole
Central compartment of the sole
Lateral compartment of the sole
Forefoot
4th compartment
interosseous compartment of the foot
Dorsal compartment of the foot
5th compartment
between dorsal fascia of the foot & tarsal bones & dorsal interosseous fascia of the midfoot and forefoot
Transverse section of the foot: 1, lateral compartment; 2, central compartment; 3, medial compartment;
4, interosseous compartment. Arrows indicate the high-pressure areas that often lead to foot ulceration.

8. Overlying flexor retinaculum
4. Tarsal tunnel
Formed on the posteromedial side of the ankle by:
A depression formed by
Medial malleolus of tibia Medial &posterior surfaces of talus
Inferior surface of sustentaculum tali Medial surface of calcaneus
Overlying flexor retinaculum
Contents from ant. to post.
(Tom Dick ANd Harry)
Tibialis posterior tendon
Flexor digitorum longus tendon
Posterior tibial artery
Tibial nerve
Flexor hallucis longus tendon

9. 5. Flexor retinaculum
Attaches above to medial malleolus below to calcaneus
2 compartments on the posterior surface of medial malleolus for tibialis posterior & flexor digitorum longus tendons
Laterally
posterior tibial artery ,veins & tibial nerve through tarsal tunnel into sole of foot
Lateral to tibial nerve
tendon of flexor hallucis longus
Pulse of posterior tibial artery through flexor retinaculum midway between medial malleolus and calcaneus

10. Prevent tendon bowing during extension of the foot and toes
6. Extensor retinacula
Prevent tendon bowing during extension of the foot and toes
Superior extensor retinaculum Superior to the ankle
Attached to anterior borders of the fibula & tibia
Inferior retinaculum
Y-shaped
Attached to lateral side of calcaneus
Extensor digitorum longus &
fibularis tertius tendons
Medially
Dorsalis pedis artery
Extensor hallucis longus tendon
tibialis anterior tendon
pass under extensor retinacula

11. Superior fibular retinaculum Inferior fibular retinaculum
7. Fibular (Peroneal) retinacula
Bind the tendons of
fibularis longus & fibularis brevis
to lateral side of the foot
Superior fibular retinaculum
Between lateral malleolus & calcaneus
Inferior fibular retinaculum
Attaches to lateral surface of calcaneus around fibular trochlea

12. 8. Plantar aponeurosis
A thickening of deep fascia in the sole of the foot
A thick central part
Weaker medial and lateral parts
Tougher, denser, and elongated than palmar aponeurosis
Anchored to the medial process of calcaneal tuberosity
Supports the longitudinal arch of the foot & protects deeper structures in the sole

13. 9. Fibrous sheaths of toes
Flexor digitorum longus, flexor digitorum brevis, & flexor hallucis longus tendons enter fibrous digital sheaths on plantar aspect of digits.
Formed by fibrous arches & cruciate (cross-shaped) ligaments
Hold the tendons to the bony plane and prevent tendon bowing when the toes are flexed.

14. 10. Extensor hoods
Extensor digitorum longus, extensor digitorum brevis, and extensor hallucis longus expand over the proximal phalanges to form complex dorsal digital expansions ("extensor hoods").
Many of the intrinsic muscles of the foot insert here.
This allows the forces from these muscles to be distributed over the toes
to cause flexion of the metatarsophalangeal joints while at the same time extending the interphalangeal joints.

15. MUSCLES
OF THE FOOT
IN 4 QUESTIONS

16. 20 individual muscles of the foot
14 located on the plantar aspect
2 on the dorsal aspect
4 intermediate in position
Plantar muscles function primarily as a group during the support phase of stance, maintaining the arches of the foot
Few delicate functions compared to hand muscles
Concerned with supporting the arches of the foot

17. Muscles in the dorsum
Extensor digitorum brevis
Attached to a roughened area on the superolateral surface of the calcaneus lateral to the tarsal sinus
Extensor hallucis brevis
The part of the muscle associated with the great toe
Deep fibular nerve

18. Organized into four layers From superficial to deep
Muscles in the sole
Organized into four layers
From superficial to deep
or plantar to dorsal
First layer
Medial to lateral
Abductor hallucis
Flexor digitorum brevis Abductor digiti minimi
Second layer
Quadratus plantae Lumbrical muscles
Third layer
Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi brevis
Fourth layer
Dorsal & plantar interossei

19. 1st layer 2nd layer 3rd layer 4th layer
Functions & innervations of the muscles of the foot
1st layer
Medial plantar nerve (S2, S3)
Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi
Lateral plantar nerve (S2, S3)
2nd layer
Assists flexor digitorum longus in flexing lateral four digits
Quadratus plantae
Flex proximal phalanges, extend middle & distal phalanges of lateral four digits
Lumbricals
3rd layer
4th layer
Plantar interossei (three muscles)
Adduct digits (2-4) and flex metatarsophalangeal joints
Dorsal interossei (four muscles)
Abduct digits (2-4) and flex metatarsophalangeal joints
Flexor hallucis brevis
Adductor hallucis
deep branch
Flexor digit minimi brevis superficial branch

20. ARTERIES
OF THE FOOT
IN 5 QUESTIONS

21. Posterior tibial artery
Supply of the foot
Terminal branches of
anterior tibial artery & posterior tibial artery
dorsalis pedis artery & plantar arteries
Posterior tibial artery
in the sole divides into
lateral & medial plantar arteries
Lateral plantar artery +Dorsalis pedis artery
Deep plantar arch

22. Lateral & medial plantar arteries
Lateral plantar artery
Major branches of the deep plantar arch
Digital branch to lateral side of little toe
4 plantar metatarsal arteries
3 perforating arteries
Medial plantar artery
Passes deep to the abductor hallucis
Ends by joining the digital branch of the deep plantar arch
Superficial branch

23. Dorsalis pedis artery
Major source of blood supply to forefoot
Continuation of anterior tibial artery
Begins midway between malleoli
Runs deep to inferior extensor retinaculum between extensor hallucis longus & extensor digitorum longus tendons on the dorsum of the foot

24. Dorsalis pedis artery
Passes inferiorly as
deep plantar artery
Joins deep plantar arch in the sole of the foot.
Branches
lateral and medial tarsal branches
arcuate artery
first dorsal metatarsal artery

25. VEINS
OF THE FOOT
IN 2 QUESTIONS

26. As in the rest of the lower limb, there are both superficial and deep veins in the foot.
Unlike the leg and thigh, however, the venous drainage of the foot is primarily to the major superficial veins

27. Dorsal metatarsal veins
Dorsal digital veins
Dorsal metatarsal veins
Dorsal venous network of the foot
Dorsal venous arch of the foot
Medial side
Lateral side
Great saphenous vein
Small saphenous vein

28. NERVES
OF THE FOOT
IN 8 QUESTIONS

29. Tibial nerve
Deep fibular nerve
Superficial fibular nerve
Sural nerve
Saphenous nerve
All intrinsic muscles of the foot except for the extensor digitorum brevis, innervated by the deep fibular nerve
Deep fibular nerve often also contributes to innervation of the first and second dorsal interossei.

30. medial malleolus & heel
Tibial nerve
Enters the foot through
tarsal tunnel
posterior to medial malleolus
Lateral to posterior tibial artery
Medial calcaneal branches heel
Midway between
medial malleolus & heel
large Medial plantar nerve
smaller Lateral plantar nerve

31. Medial plantar nerves
Larger & more anterior terminal branch Arises deep to the flexor retinaculum
Major sensory nerve in the sole
Compared to lateral plantar nerve, supplies more skin area but fewer muscles.
Its distribution to both skin and muscles of comparable to that of the median nerve in the hand.
Skin on most of the anterior two-thirds of the sole and adjacent surfaces of the medial three and one-half toes, which includes the great toe.
Four intrinsic muscles- abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and the first lumbrical.

32. Lateral plantar nerve
Smaller & more posterior terminal branch
Also courses deep to the abductor hallucis but runs anterolaterally between the 1st and 2nd layers of plantar muscles, on the medial side of the lateral plantar artery.
lateral compartment, dividing into superficial and deep branches.

33. Two plantar digital nerves (one common and one proper)
Lateral plantar nerve
Superficial branch
Two plantar digital nerves
(one common and one proper)
Skin of the plantar aspects of the lateral one and a half digits, the dorsal skin and nail beds of their distal phalanges, and skin of the sole proximal to them.

34. Deep fibular nerve
Passes deep to extensor retinaculum
Enters dorsal aspect of the foot on the lateral side of dorsalis pedis artery.
Muscles on dorsum of the foot
When finally emerges as a cutaneous nerve, so far distal in the foot ;
small area of skin remains available for innervation: web of skin between and contiguous sides of the 1st and 2nd toes
Divides into two dorsal digital nerves

35. Superficial fibular nerve
Emerges as a cutaneous nerve about two thirds of the way down the leg
Skin on the anterolateral aspect of leg
Divides into
Medial and intermediate dorsal cutaneous nerves
Most of the skin on the dorsum of the foot
Terminal branches
Dorsal digital nerves
(common & proper)
Skin of the proximal aspect of the medial half of the great toe & that of the lateral three and a half digits.

36. Sural nerve
Cutaneous branch of tibial nerve Originates high in the leg
Sural nerve formation:
Medial sural cutaneous nerve (from the tibial nerve)
Sural communicating branch of common fibular nerve
Accompanies small saphenous vein Enters the foot posterior to the lateral malleolus
ankle joint & skin on the lateral side of the foot and dorsolateral surface of the little toe.

37. Saphenous nerve
Longest & most widely distributed cutaneous branch of the femoral nerve
Only branch to extend beyond the knee
Originates in the thigh
Skin and fascia on the anteromedial aspect of the leg, ankle joint
Skin along the medial side of the foot as far anteriorly as the head of the 1st metatarsal , medial side of the proximal foot

38. Cutaneous innervation of the foot
Medially
Saphenous nerve distally to the head of 1st metatarsal
Superiorly (dorsum of foot)
Superficial (primarily)
Deep fibular nerves
Inferiorly (sole of foot)
Medial & lateral plantar nerves
Laterally
Sural nerve
Posteriorly (heel)
Medial & lateral calcaneal branches of tibial & sural nerves, respectively

39. LYMPHATIC DRAINAGE
OF THE FOOT

40. Medial superficial lymphatic vessels Accompany great saphenous vein
medial side of the dorsum & sole of the foot
Accompany great saphenous vein
Lateral superficial lymphatic vessels
lateral side of the dorsum & sole of the foot
Accompany small saphenous vein
Deep inguinal lymph nodes
Iliac lymph nodes