Hello everybody,hope you all are doing well and i am too.we are in the process of learning of lower limb and we finished one major nerve common peroneal nerve.now we are going to learn about Tibial nerve.there is so much to learn about it.so lets learn tibial nerve and it course.

TIBIAL NERVE

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It is originated from anterior division of L4,L5,S1,S2,S3

It is a part of sciatic nerve

It supplies Posterior compartment of thigh and leg

First we have to know what muscles are present in posterior compartment in thigh and leg

POSTERIOR COMPARTMENT OF THIGH

• Muscles - "Hamstrings"

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1)Semitendinosus
2)Semi membranous
3)Biceps femoris(it has long head and short head)
Longhead of biceps femoris is supplies by Tibial nerve
Short head of biceps femoris is supplies by Common peroneal nerve
This is the only exception we can see

The above three muscles are called as True hamstrings

4)Adductor magnus - it is "hybrid muscle"(muscle which is supplied by two nerves)

Adductor part of adductor magnus is supplied by Obturator nerve

Hamstring part is supplied by Tibial nerve

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Short head of biceps femoris and adductor magnus are called as modified or false hamstring muscles

• Action - flexion of knee joint

POSTERIOR COMPARTMENT OF LEG

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1)Lateral head and medial head of gastrocnemius muscle
2)Soleus muscle - it is called peripheral heart
3)plantatis muscle- it has longest tendon in the whole body
4)Tibialis posterior
5)Flexor hallucis longus
6)Flexor digitorum longus

• Action - plantarflexion/flexion of foot

1,2,3 muscles are considered as muscles present in superficial layer

4,5,6 muscles are considered as muscles present in deep layer

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CLINICAL ASPECTS

• Why soleus muscle is called as peripheral heart?

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The reason is when we are running or walking the soleus muscle contracts and relaxes as a result the venous blood pumped back into the circulation
It prevents varicose veins

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This is the reason we have walk/run daily put some work to soleus muscle so that we won't get varicose veins.we should not encourge our daily life to sedentary lifestyle

• Triceps surae
  It is the combination of lateral&medial heads of gastrcnemius and soleus muscle

• Neurovascular bundle is absent in the superficial layer of the posterior compartment of leg

• Loss of flexion of knee joint and loss of plantar flexion

The tibial nerve then divides into Medial plantar nerveand Lateral plantar nerve and supplies to 4 layers of foot.

Muscles of foot

The foot of muscles are arranged in 4 layers.these muscles are supplies by Medial plantar nerve and Lateral plantar nerve

In upper limb we learnt that ulnar nerve is considered as dominant nerve of hand as it supplies 15 muscles of hand out 20.

Like that in foot also,the Lateral plantar nerve is considered as dominant nerve in the foot because it supplies most of muscles of foot except 4 muscles which are supplies by Medial plantar nerve

[Image source](Flexes the lateral four digits at the proximal interphalangeal joints)

• 1st layer of sole of foot

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Muscle	Nerve supply	Action
Abductor hallucis	Medial plantar nerve	Abducts and flexes the great toe
Abductor digiti minimi	Lateral plantar nerve	Abducts and flexes the 5th digit
Flexor digitorum brevis	Medial plantar nerve	Flexes the lateral four digits at the proximal interphalangeal joints

• 2nd layer of sole of foot

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Muscle	Nerve supply	Action
Quadratus plantae/Flexor digitorum accessories	Lateral plantar nerve	Assists flexor digitorum longus in flexing the lateral four digits
Lumbricals L1(Unipennate)	Medial plantar nerve	Flexes at the metatarsophalangeal joints, while extending the interphalangeal joints
Lumbricals L2,L3,L4(Bipennate)	Lateral plantar nerve	Flexes at the metatarsophalangeal joints, while extending the interphalangeal joints

Two tendons are present in this layer

Flexor hallucis longus tendon and Flexor digitorum longus tendon

• 3rd layer of sole of foot

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Muscle	Nerve supply	Action
Flexor hallucis brevis	Medial plantar nerve	Flexes the proximal phalanx of the great toe at the metatarsophalangeal joint
Flexor digiti minimi	Lateral plantar nerve	Flexes the proximal phalanx of the fifth digit
Adductor hallucis	Lateral plantar nerve	Adduct the great toe. Assists in forming the transverse arch of the foot

• 4th layer of sole of foot

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Muscle	Nerve supply	Action
Plantar interossei-3(Unipennate)	Lateral plantar nerve	Adduct digits three to five and flex the metatarsophalangeal joints
Dorsal interossei-4(Bipennate)	Lateral plantar nerve	Abduct digits two to four and flex the metatarsophalangeal joints

Medial plantar nerve supplies only 4 muscles of sole of foot and remaining muscles all are supplied by Lateral plantar nerve.

The 4 muscles which are suppled by Medial plantar nerve are -

1)Abductor hallucis
2)Flexor digitorum brevis
3)First lumbrical
4)Flexor hallucis brevis*

Cutaneous branches of Tibial nerve

It is sensory supply to skin
It supplies to plantar surface too.

Nerve	Cutaneous area supplied by nerve
Lateral plantar nerve	Lateral 1½ digits of foot
Medial plantar nerve	Medial 3½ digits of foot

Tibial nerve gives a cutaneous branch called sural nerve

Sural nerve supplies to the skin on lateral side of leg and the foot

Thanks for reading,
With regards