Anatomy of Ankle and Foot describing ankle joint, sub talar joint, bones and muscles involved in ankle and foot, arches of foot

1. Anatomy Of Ankle And Foot
Dr. Vaibhav Vira

2. Ankle
• A/k/a talocrural joint
• A diarthrodial articulation involving the
distal tibia and fibula and the body of the
talus
• the only example in the human body of a
true mortise joint

3. True Mortise

4. Foot
• The human foot is a complex structure
adapted to allow orthograde bipedal stance
and locomotion and is the only part of the
body that is in regular contact with the ground
• There are 28 separate bones in the human
foot, including the sesamoid bones of the first
metatarsophalangeal joint, and 31 joints,
including the ankle joint.

5. Foot (cont.)
• Functionally, the skeleton of the foot may be
divided into the tarsus, metatarsus and
phalanges.
• Anatomically it is divided into -
• The hindfoot comprises the calcaneus and talus
• The midfoot comprises the navicular, cuboid and
three cuneiforms
• The forefoot comprises five metatarsals, fourteen
phalanges and two sesamoid bones of the great
toe

6. Bones

7. Distal Tibia
• The distal end of the tibia has 5 surfaces namely
anterior, medial, posterior, lateral and distal
surfaces, and projects inferomedially as the
medial malleolus
• The distal surface, also called the tibial plafond,
articulates with the talus and is wider anteriorly
than posteriorly
• The medial malleolus is short and thick, and has a
smooth lateral surface with a crescentic or
comma-shaped facet that articulates with the
medial surface of the talar body

8. Distal Fibula
• The distal end of the fibula or lateral malleolus projects
distally and posteriorly relative to the medial malleolus
• Its lateral aspect is subcutaneous, the posterior surface
has a broad groove with a prominent lateral border,
and the anterior surface is rough and somewhat
rounded and articulates with the anteroinferior aspect
of the tibia.
• The medial surface has a triangular articular facet and
is vertically convex with its apex directed distally. It
articulates with the lateral talar surface. Behind the
facet is a rough malleolar fossa for ligamentous
attachment

11. Tarsus
• The seven tarsal bones occupy the proximal half of
the foot
• The tarsus and carpus are homologous, but the tarsal
elements are larger, reflecting their role in
supporting and distributing body weight.
• The proximal row is made up of the talus and
calcaneus
• The distal row contains, from medial to lateral, the
medial, intermediate and lateral cuneiforms and the
cuboid.

12. • Medially, there is an additional single
intermediate tarsal element, the navicular.
• Collectively, these bones display an arched
transverse alignment that is dorsally convex.
Medially, the navicular is interposed between the
head of the talus and the cuneiforms. Laterally,
the calcaneus articulates with the cuboid.
• The tarsus and metatarsus are arranged to form
intersecting longitudinal and transverse arches.
Hence, thrust and weight are not transmitted
from the tibia to the ground (or vice versa)
directly through the tarsus, but are distributed
through the tarsals and metatarsals to the ends
of the longitudinal arches.

13. Foot Bones

14. Talus
• The talus is an intercalated bone with no tendinous
attachments. It is the osseous link between the foot and leg
through the ankle joint. It is the second largest tarsal bone
• It Has Head, Neck And Body
• Head:- Directed distally and somewhat inferomedially, the
head has a distal surface, which is ovoid and convex; its
long axis is also inclined inferomedially to articulate with
the proximal navicular surface.
• The Neck is the narrow, medially inclined region between
the head and body.
• The body is cuboidal in shape, superior (trochlear) surface
articulates with tibia, inferior surface articulates with
calcaneum, medial surface articulates superiorly with
medial malleolus of tibia, lateral surface articulates with
lateral malleolus of fibula, and small posterior surface

16. Calcaneus
• In Latin Heel, forms prominence of heel
• The calcaneus is the largest of the tarsal bones
and projects posterior to the tibia and fibula
as a short lever for muscles of the calf
attached to its posterior surface.
• It is irregularly cuboidal, its long axis directed
forwards, upwards and laterally.
• It has 6 surfaces namely, anterior, posterior,
superior or dorsal, plantar, medial and lateral.

17. • Anterior surface is smallest surface and
articulates with cuboid.
• Posterior surface is where tendocalcaneus (tendo
achillis) and plantaris is attached.
• Superior surface is where it articulates with talus.
• The plantar surface is rough and has three
tubercles i.e. medial, lateral and anterior. Plantar
ligament is attached on this surface.
• Lateral surface is rough and flat
• Medial surface is concave and have process called
sustentaculum tali which assist in formation of
talocalcaneonavicular joint

19. Navicular
• Boat shaped
• The navicular articulates with the talar head
proximally and with the cuneiform bones
distally.
• 6 Surfaces namely anterior, posterior, superior
or dorsal, plantar, medial and lateral.
• Anterior surface articulates with three
cuneiforms

21. Cuneiform Bones
• Cuneiform = Wedge shaped
• 3 Bones:- medial, intermediate and lateral
• Medial is the largest and intermediate is smallest
cunieform bone
• Medial cuneiform has 6 surfaces
• Intermediate cuneiform has 4 surfaces
• Lateral cuneiform has 3 surfaces
• Articulate with the navicular proximally and with
the bases of the first to third metatarsals distally

22. Cuboid
• The cuboid, the most lateral bone in the distal
tarsal row, lies between the calcaneus
proximally and the fourth and fifth
metatarsals distally.
• As name suggest it is cuboid, it has 6 surfaces
namely anterior, posterior, superior (plantar)
or dorsal, medial and lateral.

24. Metatarsus
• Metatarsus is made up of 5 metatarsal bones
numbered from medial to lateral.
• Each metatarsal is miniature long bones
having shaft, base and head.
• Except for the first and fifth, the shafts are
long and slender, longitudinally convex
dorsally, and concave on their plantar aspects.

26. Phalanges
• 28 phalanges
• 14 in each foot
• 2 in great toe and 3 for each of other toes

27. Soft Tissues Around Ankle Foot
• Retinacula at the ankle:- Extensor Retinacula
(Superior and Inferior), Flexor Retinaculum
• Synovial Sheats at the Ankle
• Plantar Aponeurosis
• Fibular Retinacula (Superior And Inferior)

28. Extensor Retinacula
• Deep fascia is thickened to form bands called
retinaculum.
• So called because they retain tendons in the
place.
• On front of the ankle there are extensor
retinacula
• Superior Extensor Retinaculum:-
– Medially attached to the lower part of the anterior
border of tibia
– Laterally attached to the anterior boundary of the
elongated triangular area just above lateral malleolus.

29. Extensor Retinaculum (cont.)
• Inferior Extensor Retinaculum:-
– Y shaped band of deep fascia, situated in front of the ankle
joint and over posterior part of dorsum of the foot
– Stem of Y is laterally, and upper and lower bands medially
– Stem is attached to the anterior non articulating part of
the superior surface of the calcaneum, in front of the
sulcus calcanei
– Upper band passes upwards and medially, and attaches to
anterior border of medial malleolus
– Inferior band passes downward and medially and attaches
to the plantar aponeurosis

30. Extensor Retinaculum (cont.)
• Structures passing under Superior and Inferior
Extensor Retinaculum are (from Medial to
Lateral):-
– Tibialis Anterior
– Extensor Hallucis Longus
– Anterior Tibial Vessels
– Deep Peroneal Nerve
– Extensor Digitorum Longus
– The Peroneus Tertius

31. Extensor Retinaculum (cont.)

32. Flexor Retinaculum (Tarsal Tunnel)
• 2.5cm broad
• Attachments:-
– Anteriorly to the posterior border and tip of the
medial malleolus
– Posteriorly and laterally to the medial tubercle
• Structures passing deep to retinaculum are
(from medial to lateral):
– The tendon of the tibialis posterior
– The tendon of the flexor digitorum longus

33. – Posterior tibial artery and terminal branch with
accompanying veins.
– Tibial Nerve and its branches
– Tendon of Flexor hallucis longus
Lowest Part of
the deep surface
of retinaculum
give origin to
greater part of
abductor hallucis
muscle

34. Plantar Aponeurosis
• It is the thickened central part of deep fascia
• The plantar aponeurosis is composed of
densely compacted collagen fibres orientated
mainly longitudinally, but also transversely.
• It represents distal part of plantaris which was
seperated from rest of muscle during
evolution.
• It is triangular in shape with apex being
proximal.

35. • Apex is attached to medial tubercle of the
calcaneum, proximal to attachment of flexor
digitorum brevis
• Base is distal and divides into five processes near
the head of the metatarsal bones.
• Each process splits into superficial and deep slip.
• Superficial slip is attached to skin
• Deep slips embrace flexor tendons and blends
with fibrous flexor sheet and deep transverse
ligaments.

36. • It divides the sole into three compartments by
septas
• Function of Plantar Aponeurosis:
– Fixes the skin to the sole
– Protects the deeper structures
– Helps in maintaining the longitudinal arches of the
foot
– Gives origin to muscles of the first layer of the sole

38. Synovial Sheats at Ankle
• Anterior to the ankle, the synovial sheath for tibialis
anterior extends from the proximal margin of the superior
extensor retinaculum to the interval between the diverging
limbs of the inferior retinaculum.
• Posteromedial to the ankle, the sheath for tibialis posterior
starts approximately 4 cm above the medial malleolus and
ends just proximal to the attachment of the tendon to the
tuberosity of the navicular
• Posterolateral to the ankle, the tendons of fibularis longus
and brevis are enclosed in a single sheath deep to the
superior fibular retinaculum. This sheath splits into two
separate sheaths enclosing their respective tendons deep
to the inferior fibular retinaculum.

39. Fibular Retinacular
• The fibular retinacula are fibrous bands that retain the tendons
of fibularis longus and brevis in position as these tendons cross
the lateral aspect of the ankle region.
• The superior fibular retinaculum is a short band that extends
from the back of the lateral malleolus to the deep transverse
fascia of the leg and the lateral surface of the calcaneus. Damage
to the retinaculum can lead to instability of the tendons of
fibularis longus and brevis.
• The inferior fibular retinaculum is continuous in front with the
inferior extensor retinaculum, and is attached posteriorly to the
lateral surface of the calcaneus. Some of its fibres are fused with
the periosteum on the fibular trochlea (peroneal trochlea or
tubercle) of the calcaneus, forming a septum between the
tendons of fibularis longus and brevis.

41. Lateral Ligaments ("T" shaped)
• Anterior talofibular
(weakest and most
frequently injured)
• Calcaneofibular
(strongest of the
three ligaments)
• Posterior talofibular
Lateral
It consist of three bands namely

42. Specialised adipose tissue
• Heal and metatarsal pads.
• The heel is subject to repeated high impacts and is
anatomically adapted to withstand these pressures.
• The adult heel pad has an average thickness of 18 mm and
a mean epidermal thickness of 0.64 mm (dorsal epidermal
thickness averages 0.069 mm).
• The heel pad contains elastic adipose tissue organized as
spiral fibrous septa anchored to each other, to the
calcaneus and to the skin.
• The septa are U-shaped, fat-filled columns designed to
resist compressive loads and are reinforced internally with
elastic diagonal and transverse fibres, which separate the
fat into compartments.

43. • In the forefoot, the subcutaneous tissue consists of
fibrous lamellae arranged in a complex whorl
containing adipose tissue attached via vertical fibres to
the dermis superficially and the plantar aponeurosis
deeply.
• The fat is particularly thick in the region of the
metatarsophalangeal joints, which cushions the foot
during the toe-off phase of gait (see below).
• Like the heel pad, the metatarsal fat pad is designed to
withstand compressive and shearing forces.
• Atrophy of either may be a cause of persistent pain in
the distal plantar region.

44. JOINTS
• 33 joints and 26
bones.
• Two major joints
• The Ankle Joint
• The second major
joint is the Subtalar
Joint
T
MMLM

45. Ankle Joint
• The ankle joint is a synovial joint of hinge variety,
approximately uniaxial.
• The lower end of the tibia and its medial
malleolus, together with the lateral malleolus of
the fibula and inferior transverse tibiofibular
ligament, form a deep recess (‘mortise’) for the
body of the talus.
• Structurally it is a strong joint and stability is
ensured by close interlocking of articular surface,
strong collateral ligament and tendon that cross
the joint.

47. Ankle Joint
• Ligaments
– Fibrous Capsule
– The Deltoid or medial Ligament
– A lateral ligament
• Fibrous Capsule
– Surrounds the joint
– Weak anteriorly and posteriorly to allow hinge movement
– Attached all around the articular margins except
• Posterosuperiorly attached to inferior tibiofibular ligament
• Anteroinferiorly attached to dorsum of the neck of the talus at
some distance from trochlear surface

48. • Deltoid Or Medial Ligament
– It is a strong, triangular band, attached to the apex
and the anterior and posterior borders of the
medial malleolus. It consist of superficial and deep
part.
– Excessive tensile force results in avulsion fracture
rather than a tear of ligament

49. The Deltoid Ligament
• Deltoid ligament is
a combination of:
– Anterior talotibial
– Tibionavicular
– Tibiocalcaneal
– Posterior talotibial
Medial

52. SubTalar Joint
• 3 joints between talus and calcaneum namely
posterior, anterior and medial.
• The posterior joint is named talocalcanean or
subtalar joint.
• Anterior joints is part of talocalcaneonavicular
joint.
• Since the three joints form a single functional
unit, clinicians often include these joints
under the term subtalar joint.

53. • However, the sinus tarsi seperates posterior
articulation from the anterior and medial
articulations.
• The greater part of the talocalcaneonavicular
joint lies in front of the head of the talus and
not below it.

55. Talocalcanean Joint
• It is a plain synovial joint between the concave
facet on inferior surface of the body of talus
and convex facet on superior surface of the
calcaneum.
• The Bones are connected by:-
– A fibrous capsule
– The lateral and medial talocalcanean ligaments
– The interosseous talocalcanean ligament
– The cervical ligament

56. Interosseous talocalcanean ligament
• it is thick and very strong.
• It is the chief bond of union between talus and
calcaneum.
• Occupies sinus tarsi
• Seperates talocalcanean joint from
talocalcaneonavicular joint.
• Becomes taut in eversion and limits this
movement

58. • Cervical ligament:-
– It is placed lateral to sinus tarsi.
– It becomes taut in inversion and limits this
movement.
• Collateral ligaments of ankle joint provide
stability to the talocalcanean joint.
• Movement
– Inversion and Eversion

60. Talocalcaneonavicular Joint
• Some features of ball and socket joint
• Head of talus fits into a socket formed partly
by navicular bone and partly by calcaneum.
• Two ligaments also take part in forming the
socket
– Medially by the spring ligament
– Laterally by medial limb of bifurcate ligament

61. • Bones are connected by fibrous capsule
• Movements
– Inversion
– Eversion

62. Spring Ligament
• A/k/a Plantar calcaneonavicular ligament
• It is powerful
• Attached posteriorly to anterior margin of
substentaculum tali, and anteriorly to the plantar
surface of the navicular bone.
• Head of talus rest directly on the upper surface of
the ligament.
• Plantar surface supported by tendon of tibialis
posterior medially and by tendons of flexor
hallucis longus and flexor digitorum longus,
laterally.
• Most Important ligament for maintaining medial
longitudinal arch of foot.

64. Calcaneocuboid Joint
• Saddle Joint.
• Articular surface of calcaneum and cuboid is
concavoconvex.
• Bones are connected by
– A fibrous capsule
– The lateral limb of the bifurcate ligament
– The long plantar ligament
– The short plantar ligament

66. • Bifurcate Ligament
– Y shaped
– Stem attached to anterolateral part of sulcus
calcanei
– Medial limb/ calcaneonavicular ligament attached
to dorsolateral surface of navicular bone
– Lateral limb/ calcaneocuboid ligament attached to
dorsomedial surface of cuboid bone

68. • Long Plantar Ligament is a long and strong
ligament whose importance in maintaining
arches of foot.
• It is attached to plantar surface of calcaneum
posteriorly and cuboid bone anteriorly.
• Short plantar ligament lies deep to the long
plantar ligament.
• It is broad and strong ligament extending from
anterior tubercle of calcaneus to plantar surface
of cuboid bone.

70. Inversion And Eversion Of Foot
• Inversion is movement in which the medial
border of the foot is elevated, so that sole faces
medially.
• Eversion is a movement in which the lateral
border of foot is elevated, so that the sole faces
laterally.
• The movement can be performed voluntarily only
when foot is off the ground. When foot is on the
ground these movement help to adjust foot to
uneven ground.

71. • In these movements the entire part of the
foot below the talus moves together.
• It mainly takes place at the subtalar and
talocalcaneonavicular joints and partly at the
transverse tarsal joint.
• Inversion is accompanied by plantarflexion of
the foot and adduction of forefoot.
• Eversion is accompanied by dorsiflexion of the
foot and abduction of the forefoot.

73. • Joints Taking Part
– Main
• Subtalar (talocalcanean)
• Talocalcaneonavicular
– Accessory
• Transvese tarsal which includes calcaneocuboid and
talonavicular joints
• Muscle Producing movement
– Inversion: Tibialis Anterior and Tibialis Posterior
– Eversion: Peroneus Longus and Peroneus Brevis

74. • Limiting Factors
– Inversion
• Tension of peronei
• Tension of cervical ligament
– Eversion
• Tension of tibialis anterior
• Tension of tibialis posterior
• Tension of deltoid ligament

75. • Inversion and eversion greatly help the foot in
adjusting to uneven and slippery ground.
When feet are supporting weight, these
movement occur in a modified form called
supination and pronation, which are forced on
the foot by the body weight

76. Smaller Joints of forefoot
• These are plane joints between the navicular, the
cuneiforms, the cuboid and the metatarsal bones.
• They permit small gliding movements, which
allow elevation and depression of the heads of
the metatarsals as well as pronation and
supination of the foot.
• There are 6 joint cavities of the foot
(talocalcanean, talocalcaneonavicular,
calcaneocuboid, 1st cuneometatarsal,
cubometatarsal and calcaneonavicular with
extension i.e. navicular with three cuneiforms
and 2nd and 3rd cuneometatarsal)

78. TarsoMetatarsal Joint
• Tarsometatarsal articulations are approximately plane
synovial joints.
• The joints are approximately on an imaginary line
traced from the tubercle of the fifth metatarsal to the
tarsometatarsal joint of the great toe, except for that
between the second metatarsal and intermediate
cuneiform, which is 2–3 mm proximal to this line.
• Movements between the tarsals and metatarsals are
limited to flexion and extension, except in the first
tarsometatarsal joint, where some abduction and
rotation occur.

79. Metatarsophalangeal Joint
• Metatarsophalangeal articulations are ovoid
or ellipsoid joints between the rounded
metatarsal heads and shallow cavities on the
proximal phalangeal bases. They are usually
2.5 cm proximal to the web spaces of the toes.
• Flexion, extension, abduction and adduction
are the movements that occur in this joints

80. Interphalangeal Joint
• Interphalangeal articulations are almost pure
hinge joints, in which the trochlear surfaces
on the phalangeal heads articulate with
reciprocally curved surfaces on adjacent
phalangeal bases.
• Flexion and extension occurs in this joints

81. Muscles
• Extension of deep fascia form intermuscular
septa that divide leg into compartments.
• The anterior and posterior intermuscular
septa are attached to anterior and posterior
borders of fibula dividing leg into anterior,
posterior and lateral compartment.
• The posterior compartment is further
subdivided into superficialand deep parts by
transverse intermusclar septum

82. Muscle Compartments
• Anterior Compartment (Dorsal flexors)
– Tibialis anterior
– Peroneous tertius
– Extensor digitorum Longus
– Extensor digitorum brevis
– Extensor hallicus longus
• Lateral Compartment (Evertors)
– Peroneus longus
– Peroneus brevis

83. Muscle Compartments
• Deep Posterior Compartment (Plantar
Flexors)
– Flexor digitorum longus
– Flexor hallicus
– Tibialis Posterior
• Superficial Posterior Compartment(Plantar
Flexors)
– Gastrocnemius
– Soleus
– Plantaris

84. Ankle and Foot Muscles
• Superficial Posterior
Compartment
– Gastrocnemius
– Soleus
– Plantaris
• Deep Posterior
Compartment
– Flexor digitorum longus
– Flexor hallicus
– Tibialis Posterior
• Lateral Compartment
(Evertors)
– Peroneus longus
– Peroneus brevis
• Anterior Compartment
(Dorsal flexors)
– Tibialis anterior
– Peroneous tertius
– Ext. dig. Longus
– Ext. hallicus

85. Gastrocnemius
• Origin: posterior surface of the two
femur condyels
• Insertion: posterior surface of the
calcaneus via Achilles tendon
• Actions:
– plantar flexion of the foot
– flexion of the knee
• Stronger plantar flexion when the
knee is extended
• Superficial posterior compartment
Posterior

86. Soleus
• Located beneath the gastrocnemius
• Origin: upper 2/3 of the posterior
surfaces of the tibia and fibula
• Insertion: posterior surface of the
calcaneus via Achilles tendon
• Action:
– plantar flexion
• Superficial posterior compartment
Posterior

87. Gastrocnemius & Soleus
•Gastronemius and Soleus = “triceps surae” due to their three heads

89. Achilles Tendon
• Named after
Achilles
• Largest tendon
• 1000 pounds of
force
• Tendon of the
Gastrocnemius and
Soleus

90. Plantaris
• Absent in some humans
• Origin: lateral epicondyle
• Insertion: calcaneus
• Actions:
– plantar flexion
• Superficial posterior
compartment
Posterior

92. Tibialis posterior
• Origin: posterior surface of the upper
half of the adjacent surface of tibia &
fibula
• Insertion: navicular, cuneiforms, and
cuboid bones and bases of the 2nd-5th
metatarsal bones.
• Note: passes posterior to medial
malleolus.
• Actions:
– plantar flexion
– inversion of the foot
• Deep posterior compartment
Posterior

93. Flexor Digitorum Longus
• Origin: middle 1/3 of the posterior surface
of the tibia
• Insertion: base of the distal phalanges of
each of lateral four toes
• Note: passes posterior to medial malleolus.
• Actions:
– toe flexion
– plantar flexion,
– inversion of the foot
• Maintains the longitudinal arch
• Deep posterior compartment
Posterior

94. Flexor Hallicus Longus
• Origin: middle half of the posterior surface
of the fibula
• Insertion: distal phalanx of the large toe,
plantar surface
• Note: passes posterior to medial malleolus.
• Actions:
– Flexion of the great toe
– Inversion
– Plantar flexion
• Deep posterior compartment
Posterior

96. Tibialis anterior
• Origin: upper 2/3 of the anterior
surface of the tibia
• Insertion: medial cuneform and the
first metatarsal
• Note: passes anterior to medial
malleolus.
• Actions:
– Dorsal flexion
– Inversion.
• Anterior compartment
Anterior

97. Extensor hallicus longus
• Origin: middle 2/3 of the inner surface
of the front of the fibula
• Insertion: top of the distal phalanx of
the great toe
• Note: passes anterior
• Actions:
– Extension of big toe
– Dorsiflexion
– Weak inversion of the foot
• Anterior compartment
Anterior

98. Extensor digitorum longus
• Origin: lateral condyle of the tibia and
anterior surface of the fibula
• Insertion: middle and distal phalanges of
the four lateral toes.
• Note: passes anterior to lateral malleolus.
• Actions:
– Toe extension
– Dorsiflexion
– Eversion
• Anterior compartment
Anterior

99. Extensor Digitorum Brevis
• Origin: Anterior part of the superior
surface of the calcaneum
• Inserion: middle and distal phalanges
of the four medial toes.
• Note: Medial most part of muscle
which is distict is known as extensor
hallucis brevis
• Action:
– Toe Extension
• Anterior Compartment

100. Peroneous tertius
• Origin: lower fibula
• Insertion: dorsal surface of
the 5th metatarsal
• Note: passes anterior to
lateral malleolus.
• Action:
– Dorsiflexion
– Eversion
• Anterior compartment
Anterior

102. Peroneus longus muscle
• Origin: head and upper 2/3 of the outer
surface of the fibula
• Insertion: undersurfaces of the 1st
cuneiform and first metatarsal bones
• Note: passes posterior to lateral malleolus.
• Actions:
– Eversion
– Plantar flexion
• The tendon goes under the foot from the
lateral to the medial surface, thus aiding in
support for the transverse arch.
• Lateral compartment
Lateral

103. Peroneus brevis muscle
• Origin: lower 2/3 of the outer surface of
the fibula
• Insertion: dorsal surface of the 5th
metatarsal
• Note: passes posterior to lateral
malleolus.
• Actions:
– Plantar flexion
– Eversion
• Anterior compartment
Lateral

104. Lateral Compartment

105. Muscles and Tendons of the Sole
• Four Layers
• Muscles of the 1st layer
– Flexor digitorum brevis
– Abductor hallucis
– Abductor digiti minimi
• Muscles of the 2nd Layer
– Tendon of the flexor digitorum longus
– Flexor hallucis longus
– Flexor digitorum accessorius
– Lumbrical muscles

106. • Muscles of the 3rd layer
– Flexor haluucis brevis
– Flexor digiti minimi brevis
– Adductor hallucis
• Muscles of the 4th layer
– Interosseous muscles
– Tendon of tibialis posterior
– Tendon of peroneus longus

116. Arches of the Foot
• Arches of the foot help in walking, running and
jumping. In addition they help in weight bearing
and in providing upright posture.
• Arches are supported by intrinsic and extrinsic
muscles in the sole, ligaments, aponeurosis and
shape of the bones.
• The Foot has to act :-
– As a pliable platform to support weight in the upright
posture
– As a lever to propel the body forward

117. • Classification of Arches
– Longitudinal
• Medial
• Lateral
– Transverse
• Anterior
• Posterior

119. Medial Longitudinal Arch
• This arch is considerably higher, more mobile and
resilient than the lateral.
• It is considered as big arch of a small circle.
• Acts as a shock absorber.
• Anterior end:- Formed by head of 1st, 2nd, 3rd
metatarsals.
• Posterior End:- Medial tubercle of the calcaneum.
• Summit:- Superior articular surface of the body of
talus

120. • Pillars
– Anterior pillar is long and weak, formed by talus,
navicular, three cuneiform bones and first three
metatarsal bones.
– Posterior pillar is short and strong, formed by
medial part of the calcaneum
• Main Joint:- Talocalcaneonavicular joint
• Phalanges do not take part in formation of the
arches

122. Lateral Longitudinal Arch
• Characteristically low and limited mobility.
• Built to transmit weight and thrust to the ground.
• Considered as small arc of big circle
• Ends:-
– Anterior:- Heads of 4th and 5th metatarsal bones
– Posterior:- Lateral tubercle of the calcaneum
• Summit:- articular facets of the superior surface
of the calcaneum at the level of sub talar joint

123. • Pillars:-
– Anterior pillar:- long and weak, formed by cuboid
bone and by 4th and 5th metatarsal bones.
– Posterior pillar:- short and strong, formed by
lateral half of the calcaneum.
– Main Joint:- Calcaneocuboid Joint

125. Anterior Transverse Arch
• Formed by the heads of the five metatarsal
bones.
• Complete arch, as heads of 1st and 5th come in
contact with the ground and forms the two
end of the arch

126. Posterior Transverse Arch
• Formed by the greater part of tarsus and
metatarsus.
• Incomplete, as only the lateral end comes in
contact with the ground forming half dome,
which is completed by similar half dome of
the opposite foot.

127. Factors Responsible for Maintenance
of Arches
• Shape of the bones concerned
• Intersegmental ties/staples or ligaments (and
muscles)
• The beams or bowstrings that connect two
ends of the arch
• Slings that keep the summit of the arch pulled
up
• Suspension

128. Bony Factor
• Posterior transverse arch is formed and
maintained mainly because of the fact that
many of the tarsal bones involved (eg. the
cuneiform bones) and the heads of the
metatarsal bones, are wedge shaped, the apex
of wedge pointing downwards.
• The bony factor is not very important in the
case of other arches

129. Intersegmental Ties
• All arches are supported by ligaments uniting
the bones concerned.
• The most important of these are
– The spring ligament for the medial longitudinal
arch
– The long and short plantar ligaments for the
lateral longitudinal arch
– In the case of transvers arch, the metatarsal bones
are held together by the interosseous muscles.

130. The Beams
• The Longitudinal arches are prevented from
flattening by the plantar aponeurosis and by
the muscles of the first layer of the sole
(Flexor digitorum brevis, flexor digiti minimi
and abductor digiti minimi ).
• These structure keep the anterior and
posterior ends of the arches pulled together.

131. Slings
• The summit of the medial longitudinal arch is
pulled upwards by tendon passing from the
posterior compartment of the leg into the sole
i.e. tibialis posterior, flexor hallucis longus,
flexor digitorum longus.
• The summit of lateral longitudinal arch is
pulled upwards by peroneus longus and
peroneus brevis.

132. Slings (cont.)
• The tendons of tibialis anterior and peroneus
longus together form a sling (stirrup) which keeps
the middle of the foot pulled upwards, thus
supporting the longitudinal arches.
• Peroneus longus runs transversly across the sole,
it pulls the medial and lateral margins of the sole
closer together, thus maintaining the transverse
arch.
• The transverse arch is also supported by tibialis
posterior which grips many of the bones of the
sole through its slips

133. Suspension
• Medial Longitudinal Arch:- Tibialis Anterior
• Lateral Longitudinal Arch:- Peroneus Longus

134. Function of Arches
• Distribute body weight to the weight to the
weight bearing areas of the sole, mainly the heel
and the toes. Out of the later, weight is borne
mainly on 1st and 5th toe. The lateral border of
the foot bears some weight, but this is reduced
due to the presence of the lateral longitudinal
arch
• The arches acts as spring (chiefly the medial
longitudinal arch) which are of great help in
walking and running

135. Function of Arches (cont.)
• The act as shock absorbers in stepping and
particularly in jumping
• The concavity of the arches protects the soft
tissues of the sole against pressure
• The character of the medial longitudinal arch
is resiliency and that of lateral longitudinal
arch is rigidity.

137. Thank You