leg front and lateral

1. The Anterior Leg

2. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint

3. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint
There are four muscles

4. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint
There are four muscles
Extensor Digitorum Longus
Also extend the toes
Extensor Hallucis Longus

5. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint
There are four muscles
Extensor Digitorum Longus
Also extend the toes
Extensor Hallucis Longus
Tibialis Anterior

6. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint
There are four muscles
Extensor Digitorum Longus
Also extend the toes
Extensor Hallucis Longus
Tibialis Anterior – also inverts the foot

7. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint
There are four muscles
Extensor Digitorum Longus
Also extend the toes
Extensor Hallucis Longus
Tibialis Anterior – also inverts the foot
Peroneus Tertius

8. The anterior compartment of the leg contains extensor
muscles that dorsiflex the ankle joint
There are four muscles
Extensor Digitorum Longus
Also extend the toes
Extensor Hallucis Longus
Tibialis Anterior – also inverts the foot
Peroneus Tertius – also known as Fibularis Tertius

9. Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L

10. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L

11. Septum
Septum
Interosseous
Membrane
Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L

12. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment

13. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment

14. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Superficial Posterior
Compartment

15. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Lateral
Compartment
Superficial Posterior
Compartment

16. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Lateral
Compartment
Anterior Compartment
Superficial Posterior
Compartment

17. Tibi
a
Fibula
Tibialis Anterior
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Lateral
Compartment
Superficial Posterior
Compartment

18. Tibi
a
Fibula
Tibialis Anterior
Extensor
Hallucis
Longus
Cross Section through middle of right leg looking up from foot
anterior
posterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Lateral
Compartment
Superficial Posterior
Compartment

19. Tibi
a
Fibula
Tibialis Anterior
Extensor
Longus
Cross Section through middle of right leg looking up from foot
anterior
posterior
Extensor
Hallucis
Digitorum
Longus
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Lateral
Compartment
Superficial Posterior
Compartment

20. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
posterior
Tibialis Anterior
Extensor
Extensor Hallucis
Digitorum Longus
Longus
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Lateral
Compartment
Superficial Posterior
Compartment

21. Tibialis Anterior

22. Tibialis Anterior
arises from
lateral surface of shaft of
Tibia
attaches to
Medial Cuneiform
1st Metatarsal base

23. Tibialis anterior muscle
Tibialis anterior tendon
Tibialis Anterior
arises from
lateral surface of shaft of
Tibia
attaches to
Medial Cuneiform
1st Metatarsal base

24. Tibialis anterior muscle
Tibialis anterior tendon
Tibialis Anterior
Dorsiflexes ankle joint
Inverts foot

25. Extensor Digitorum Longus

26. Extensor Digitorum Longus
Arises from
Fibula
Interosseous Membrane

27. Extensor Digitorum Longus
Arises from
Fibula
Interosseous Membrane
The tendon divides into four slips and
these insert into the
dorsal expansions of toes 2-5

28. The tendon divides into four slips and
these insert into the
dorsal expansions of toes 2-5

29. Extensor Digitorum Longus
Dorsiflexes the ankle joint
Extends the toes

30. Extensor Hallucis Longus

31. Extensor Hallucis Longus
Arises from the
Fibula

32. Extensor Hallucis Longus
Arises from the
Fibula
Inserts onto the
Distal Phalanx of Big Toe

33. Extensor Hallucis Longus
Extends the Big Toe
Dorsiflexes Ankle Joint
Tendon of
Extensor Hallucis Longus

34. Peroneus Tertius
also known as
Fibularis Tertius

35. Peroneus Tertius
Arises from the
Fibula

36. Peroneus Tertius
Arises from the
Fibula
Inserts onto dorsum of
5th metatarsal base

37. Peroneus Tertius
Tendon of Peroneus Tertius

38. Peroneus Tertius
Everts foot
Dorsiflexor of the foot
Tendon of Peroneus Tertius

39. Extensor Retinacula are thickenings
of deep fascia that prevent
‘bowstringing’ of the extensor
tendons

40. Extensor Retinacula are thickenings
of deep fascia that prevent
‘bowstringing’ of the extensor
tendons
Superior extensor retinaculum
Inferior extensor retinaculum

41. Nerve Supply

42. All the muscles in the Anterior Compartment
are supplied by the
Deep Peroneal Nerve

43. Deep Peroneal Nerve
Injury to this nerve causes a condition
known as ‘foot drop’
The foot can no longer be dorsiflexed which
causes difficulty in walking
The knee has to be lifted much higher in order to
prevent the foot from dragging on the ground
This is called a ‘High Stepping Gait’

44. Summary of Muscles

45. Anterior Leg
Tibialis Anterior
Origin Lateral condyle of tibia, proximal
2/3rds lateral surface tibia,
interosseous membrane
Insertion Medial and plantar surfaces of
medial cuneiform and base of
first metatarsal
Action Dorsiflexor of ankle, invertor of
foot
Nerve Supply Deep peroneal nerve (L4, L5)
Blood Supply Anterior tibial artery

46. Extensor Digitorum Longus
Origin Head of fibula, upper 2/3 anterior
fibular shaft, interosseous
membrane
Insertion Splits into 4 tendons distally;
these insert onto dorsum of
middle and distal phalanges of
toes 2-5. Part of extensor
expansion complex
Action Extends toes 2 - 5 and dorsiflexes
ankle
Nerve Supply Deep peroneal nerve (L5, S1)
Blood Supply Anterior tibial artery
Anterior Leg

47. Extensor Hallucis Longus
Origin Anterior surface of the fibula,
interosseous membrane
Insertion Base of distal phalanx great toe
Action Extends great toe and dorsiflexes
ankle
Nerve Supply Deep peroneal nerve (L5, S1)
Blood Supply Anterior tibial artery
Anterior Leg

48. Anterior Leg
Fibularis Tertius
Origin Distal 1/3rd anterior surface of
fibula
Insertion Base of dorsal aspect 5th
metatarsal
Action Dorsiflexes foot;
everts foot weakly
Nerve Supply Deep peroneal nerve (L5, S1)
Blood Supply Anterior tibial artery

49. Lateral Compartment of the Leg

50. The lateral compartment of the leg also known as
•Fibular compartment
or
•Peroneal compartment

51. The lateral compartment of the leg also known as
•Fibular compartment
or
•Peroneal compartment
It is the smallest of the 4 compartments in the leg
It contains 2 muscles that
•evert the foot
•plantarflex the ankle joint

52. The lateral compartment of the leg also known as
•Fibular compartment
•Peroneal compartment
It is the smallest of the 4 compartments of the leg
It contains 2 muscles that
•evert the foot
•plantarflex the ankle joint
1. Fibularis or Peroneus Longus
2. Fibularis or Peroneus Brevis

53. Cross Section through middle of right leg looking up from foot
posterior
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L

54. Tibi
a
posterior
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L

55. Septum
Septum
Interosseous
membrane
Tibi
a
posterior
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L

56. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
posterior
Compartment

57. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
posterior
Compartment

58. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Superficial Posterior
Compartment
Deep Posterior
posterior
Compartment

59. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Deep Posterior
Compartment
Superficial Posterior
Compartment
Anterior Compartment
posterior

60. Tibi
a
Fibula
Cross Section through middle of right leg looking up from foot
anterior
L
A
T
E
R
A
L
M
E
D
I
A
L
Superficial Posterior
Compartment
Deep Posterior
posterior
Compartment
Lateral
Compartment
Anterior Compartment

61. Fibularis or Peroneus
Longus
Arises from
-Head of the Fibula
-Upper 2/3rds of the lateral surface
of the Fibula

62. Arises from
-head of the fibula and the
-upper 2/3rds of the lateral surface
of the fibula
The tendon runs obliquely in
the sole of the foot and inserts
onto the
-Medial cuneiform
-base of 1st metatarsal
Fibularis or Peroneus
Longus

63. Fibularis or Peroneus Brevis
overlap, Peroneus Brevis
is the anterior one and
Peroneus Longus is the
posterior one.
Arises from the lower 2/3rds of the
lateral surface of the shaft of the Fibula
Where the muscles

64. Arises from the lower 2/3rds of the lateral
surface of the shaft of the fibula
Inserts onto the styloid process
at the base of the 5th metatarsal
overlap, Peroneus Brevis
is the anterior one and
Peroneus Longus is the
posterior one.
Fibularis or Peroneus Brevis
Where these muscles

65. Where the two tendons overlap
behind the lateral malleolus
Peroneus Brevis lies anterior to
Peroneus Longus
To help you remember,
think of Peroneus Longus as
‘Lounging Behind’!

66. Peroneus
Brevis lies
anterior to
Peroneus
Longus
Peroneus Longus
tendon
Peroneus Brevis tendon
Lateral Malleolus
(distal end of Fibula)

67. Both muscles are supplied by the
Superficial Peroneal Nerve
a terminal branch of the
Common Peroneal Nerve

68. Both muscles are supplied by the
Superficial Peroneal Nerve
a terminal branch of the
Common Peroneal Nerve
It has an extensive sensory distribution to the
•anterolateral aspect of distal part of
the leg
•dorsum of the foot

69. Both muscles are supplied by the
Superficial Peroneal Nerve
a terminal branch of the
Common Peroneal Nerve
It has an extensive sensory distribution to the
•anterolateral aspect of distal part of
the leg
•dorsum of the foot
It is sometimes referred to as the
Musculocutaneous Nerve of the Leg

70. Summary of Muscles

71. Peroneus or Fibularis Longus
Origin Head of fibula, upper 2/3rds of
lateral fibular shaft surface
Insertion Plantar posterolateral aspect of
medial cuneiform and lateral side
of 1st metatarsal base
Action Everts foot and plantar flexes
ankle, supports the transverse
arch of the foot
Nerve Supply Superficial peroneal nerve (L5, S1,
S2)
Blood Supply Anterior tibial and peroneal
arteries
Lateral Leg

72. Peroneus or Fibularis Brevis
Origin Lower 2/3rds of lateral fibular
surface;
Insertion Lateral surface of styloid process
of 5th metatarsal base
Action Everts foot and plantar flexes
ankle
Nerve Supply Superficial peroneal nerve (L5, S1,
S2)
Blood Supply Muscular branches of peroneal
artery
Lateral Leg