anatomy, common foot conditions

1. THE FOOT
DR. STEVEN BUYUNGO

2. PRESENTATION OUTLINE
1. Anatomy of the foot
2. Common foot conditions
3. Take-home message

3. ANATOMY
A) Bones and joints
Divided into three regions:
(i) Hind foot – talus and calcareous
(ii) Mid foot – navicular, cuboid, and cuneiforms
(iii) Fore foot – metatarsals and phalanges

4. ANATOMY CONT’D
• Tarsals – a set of seven irregularly shaped bones.
They are situated proximally in the foot in the ankle
area.
• Metatarsals – connect the phalanges to the tarsals.
There are five in number – one for each digit.
• Phalanges – the bones of the toes. Each toe has
three phalanges – proximal, intermediate, and distal
(except the big toe, which only has two phalanges

5. ANATOMY CONT’D

6. ANATOMY CONT’D
Hind foot
• The talus is the most superior and transmits the
weight of the entire body to the foot. It has three
articulations/ joints at ankle, subtalar and
talonavicular. Numerous ligamants but no muscle
originate from or insert onto it. This means there is a
high risk of avascular necrosis as the vascular
supply is dependent on fascial structures
• The calcaneus is the largest tarsal. It has two
articulations subtalar/talocalacneal and
calcaneocuboid.

7. ANATOMY CONT’D
Mid foot
• Navicular positioned medially, articulates with the
talus, all three cuneiforms and the cuboid. On the
plantar surface, there is a tuberosity for the attachment
of part of the tibialis posterior tendon.
• The cuboid is furthest lateral, lying anterior to the
calcaneus and behind the fourth and fifth metatarsals.
The inferior (plantar) surface –F.L tendon
• The three cuneiforms articulate with the navicular and
metatarsals. The shape of the bones helps form
a transverse arch across the foot. Medial cuneiform –
T.A, (part of) T.P and F.L Lateral cuneiform – F.H.B

8. ANATOMY CONT’D
Fore foot
• Metatarsals numbered I-V (medial to lateral) . Similar
structure. are convex dorsally and consist of a head,
neck, shaft, and base (distal to proximal). They have 3
joints: tarsometatarsal, intermetatarsal
metatarsophalangeal joints.
• Phalanges are the bones of the toes. The second to
fifth toes all have proximal, middle, and distal
phalanges. The great toe has only proximal and distal
. Similar in structure base, shaft, and head.

9. ANATOMY CONT’D
Muscles of the foot
• extrinsic vs. intrinsic muscles.
• The extrinsic muscles arise from the anterior,
posterior and lateral compartments of the leg. They
are mainly responsible for actions such as eversion,
inversion, plantarflexion and dorsiflexion of the foot.
• The intrinsic muscles are located within the foot and
are responsible for the fine motor actions of the foot,
for example movement of individual digits.

10. ANATOMY CONT’D
Intrinsic muscles are divided into dorsum and sole muscles.
Dorsal Aspect: Extensor digitorum brevis, and the
extensor hallucis brevis. Attachments: both originate
from the calcaneus, the interosseous talocalcaneal
ligament and the inferior extensor retinaculum. EDB
attaches to proximal phalanx of the great toe and the
long extensor tendons of toes 2-4 while EHL attaches to
proximal phalanx of the great toe
Actions: EDL extends the medial four toes at the
metatarsophalangeal and interphalangeal joints. EHL for
big toe. Innervation: Deep fibular nerve for both

11. ANATOMY CONT’D
Plantar Aspect
• There are 10 intrinsic muscles located in the sole of
the foot. They act collectively to stabilise the arches of
the foot, and individually to control movement of the
digits. All the muscles are innervated either by the
medial plantar nerve or the lateral plantar nerve,
which are both branches of the tibial nerve.
• The muscles of the plantar aspect are described in
four layers (superficial to deep)

12. ANATOMY CONT’D
• First layer is made up of 3 muscles, aBductor hallucis
for abduction and flexion of great toe innervated by
medial plantar, flexor digtorum which flexes lateral 4
toes innervated by medial plantar and adductor digiti
minimi by lateral plantar to adduct 5th toe.
• Second layer has 2 muscle, quadratus plantae by
lateral plantar, helps FDL to flex lateral 4 toes, 4
lubricals lateral 3 by lateral plantar and most medial by
medial plantar

13. ANATOMY CONT’D
• The third layer contains three muscles. The flexor
hallucis brevis by medial plantar flexes great toe ,
adductor hallucis by deep branch of lateral plantar
adducts great toe and flexor digiti minimi brevis by
superficial branch of lateral plantar flexes the 5th digit.
• Fourth layer is formed by 3 plantar and 4 interossei
muscles all supplied by lateral plantar nerve. The
plantar adduct digits 3-5 while the dorsal adducts
digits 2-4

14. ANATOMY CONT’D

15. ANATOMY CONT’D
Arches of the foot
• Medial Arch: The medial arch is the higher of the two
longitudinal arches. It is formed by the calcaneus,
talus, navicular, three cuneiforms and first three
metatarsal bones. It is supported by:
Muscular support: Tibialis anterior and posterior,
fibularis longus, flexor digitorum longus, flexor hallucis,
and the intrinsic foot muscles, Ligamentous support:
Plantar ligaments (in particular the long plantar, short
plantar and plantar calcaneonavicular ligaments),
medial ligament of the ankle joint.

16. ANATOMY CONT’D
• Lateral arch; Lies on the ground in the standing
position. It is formed by the calcaneus, cuboid and 4th
and 5th metatarsal bones. It is supported by:
Muscular support: Fibularis longus, flexor digitorum
longus, and the intrinsic foot muscles.Ligamentous
support: Plantar ligaments (in particular the long
plantar, short plantar and plantar calcaneonavicular
ligaments).
• The transverse arch: located in the coronal plane of
the foot, formed by the metatarsal bases, the cuboid
and the three cuneiform bones.

17. COMMON FOOT CONDITIONS
Congenital anomalies of the foot
Pes cavus is an unusually high medial longitudinal
arch. It can appear in early life and become
symptomatic with increasing age. Due to the higher arch,
the ability to shock absorb during walking is diminished
and an increased degree of stress is placed on the ball
and heel of the foot.
Pes planus is a common condition in which the
longitudinal arches have been lost. Arches do not
develop until about 2-3 years of age.

18. COMMON FOOT CONDITIONS
club foot :idiopathic deformity of the foot of
characterized by
• Cavus (tight intrinsic, FHL, FDL)
• Adductus of forefoot (tight tibialis posterior)
• Varus (tight tendoachilles, tibialis posterior, tibialis
anterior)
• Equinus (tight tendoachilles) talar neck is medially and
plantarly deviated
Calcaneus is in varus navicular and cuboid are medial

19. COMMON FOOT CONDITIONS
• Epidemiology
• most common musculoskeletal birth defect
• overall incidence 1:1,000, though some
populations 1:250
• male: female ratio approximately 2:1
• half of cases are bilateral
• In 80%, clubfoot is an isolated deformity

20. COMMON FOOT CONDITIONS
• Physical exam: inspection: small foot and calf
,shortened tibia, medial and posterior foot skin
creases,
Differentiated from more common positional foot
deformities by rigid equinus and resistance to passive
correction
• Radiology: AP or dorsiflexion lateral: talocalcaneal
angle is < 20° (normal is 20-40°) , also shows hindfoot
parallelism (i.e. talus and calcaneus are less divergent
than normal)

21. COMMON FOOT CONDITIONS
Management
• Nonoperative: Ponseti method of serial manipulation
and casting is the gold standard in most of the world
for untreated clubfeet. It has a > 90% success rate in
avoiding comprehensive surgical release.
• posteromedial soft tissue release and tendon
lengthening, medial column lenthening or lateral
column-shortening osteotomy, or cuboid
decancellation, talectomy

22. COMMON FOOT CONDITIONS
Tarsal tunnel syndrome: compression neuropathy of
the tibia nerve .
Causes can be intrinsic like, ganglion cyst,
tendonopathy, tenosynovitis, lipoma/tumor, peri-neural
fibrosis, osteophytes.
or extrinsic like shoes, trauma, anatomic deformity
(tarsal coalition, valgus hindfoot), post-surgical scaring,
systemic inflammatory disease, edema of the lower
extremity

23. COMMON FOOT CONDITIONS
Anatomy (posterior tarsal tunnel): flexor retinaculum
(laciniate ligament), calcaneus (medial), talus (medial),
abductor hallucis (inferior) Contents include: tibial nerve,
posterior tibial artery, FHL tendon, FDL tendon, tibialis
posterior tendon
Presents with pain on prolonged standing or walking,
tenderness of tibial nerve (Tinel's sign), muscle wasting
of foot intrinsics, pain with dorsiflexion and eversion of
the ankle

24. COMMON FOOT CONDITIONS

25. TAKE-HOME MESSAGE
• The foot is the terminal joint in the lower kinetic chain
that opposes external resistance
• The combined effect of muscle, bone, ligaments, and
normal foot biomechanics will result in the most
efficient force attenuation in the lower limb
• The static structures include the bones, joint surface
congruity, ligaments, and fascia. The dynamic
components include the arthrokinematics of the tarsal
bones and muscle function.