The tibial nerve is a branch of the
sciatic nerve
The sciatic nerve, also called the ischiadic nerve, is a large nerve in humans and other vertebrate animals. It is the largest branch of the sacral plexus and runs alongside the hip joint and down the right lower limb. It is the longest and widest ...
. The tibial nerve passes through the
popliteal fossa to pass below the arch of soleus.
Structure
Popliteal fossa
The tibial nerve is the larger terminal branch of the sciatic nerve with root values of L4, L5, S1, S2, and S3. It lies superficial (or posterior) to the popliteal vessels, extending from the superior angle to the inferior angle of the
popliteal fossa, crossing the popliteal vessels from lateral to medial side. It gives off branches as shown below:
* Muscular branches - Muscular branches arise from the distal part of the popliteal fossa. It supplies the medial and lateral heads of
gastrocnemius,
soleus,
plantaris and
popliteus muscles. Nerve to popliteus crosses the popliteus muscle, runs downwards and laterally, winds around the lower border of the popliteus to supply the deep (or anterior) surface of the popliteus. This nerve also supplies the
tibialis posterior muscle,
superior tibiofibular joint,
tibia
The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...
bone,
interosseous membrane of leg, and the
inferior tibiofibular joint.
* Cutaneous branches - Tibial nerve also gives off a
cutaneous nerve A cutaneous nerve is a nerve that provides nerve supply to the skin.
Human anatomy
In human anatomy, cutaneous nerves are primarily responsible for providing cutaneous innervation, sensory innervation to the skin. In addition to sympathetic and ...
called the
medial sural cutaneous nerve from the middle of the popliteal fossa and exits at the inferior angle. It supplies the skin of the lower half of the back of the leg and lateral border of the foot until the tip of the little toe.
* Articular branches - There are three articular branches arises from the upper part of the fossa: superior medial genicular nerve (located on the surface of
medial condyle of femur, middle genicular nerve (pierces the posterior capsule of the knee joint to supply the structures located in the intercondylar notch of the femur, and inferior genicular nerve (runs along the upper border of the popliteus to reach the medial condyle of tibia).
Back of the leg
At the inferior angle of the popliteal fossa, tibial nerve passes deep to the tendinous arch of soleus to enter the back of the leg. In the leg, it runs downwards and medially to reach the posteromedial side of the ankle, midway between the
medial malleolus
A malleolus is the bony prominence on each side of the human ankle.
Each leg is supported by two bones, the tibia on the inner side (medial) of the leg and the fibula on the outer side (lateral) of the leg. The medial malleolus is the promin ...
and medial tubercle of the calcaneum. It terminates deep to the
flexor retinaculum at the origin of the abductor hallucis by dividing into medial and lateral plantar nerves to supply the foot. The tibial nerve gives off several branches to supply the back of the leg:
* Muscular branches - Supplies tibialis posterior,
flexor digitorum longus,
flexor hallucis longus
The flexor hallucis longus muscle (FHL) attaches to the plantar surface of phalanx of the great toe and is responsible for flexing that toe. The FHL is one of the three deep muscles of the posterior compartment of the leg, the others being the ...
, and deep part of soleus.
* Cutaneus branches - The medial calcaneal nerve pierces the flexor retinaculum to supply the skin of the back and lower surface of the heel.
* Articular branches - Supplies the ankle joint
Foot
In the foot, the nerve terminates by dividing into medial and lateral plantar branches.
*
Medial plantar nerve - It is the larger terminal branch of the tibial nerve. It passes between the
abductor hallucis and
flexor digitorum brevis to divide further into branches. Its distribution resembles to that of the distribution of
median nerve
The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus.
The median nerve originates from the lateral and medial cords of the brachial plexus, and has cont ...
in the hand. Its muscular branches supply the
abductor hallucis, the
flexor digitorum brevis, the
flexor hallucis brevis and the first
lumbrical. Cutaneous distribution of the medial plantar nerve supplies the medial sole and medial three and one half toes through four digital branches. Each digital branch give off a dorsal branch to supply the nail beds on the dorsum. This nerve also gives off articular branches to supply the bones of the
tarsus and metatarsus.
*
Lateral plantar nerve - It is the smaller terminal branch of the tibial nerve. It courses laterally and forward until the base of fifth metatarsal bone, where it divides into superficial and deep branches. Its distribution resembles to the distribution of
ulnar nerve
The ulnar nerve is a nerve that runs near the ulna, one of the two long bones in the forearm. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or ...
in the hand. The main trunk of the nerve supplies two muscles: flexor digitorum accessorius and
abductor digiti minimi. This nerve also supplies the skin of the sole.
The ''superficial branch'' is divided into medial and lateral branches. The lateral branch supplies three muscles:
flexor digiti minimi, 3rd and 4th
interossei, and the skin over the lateral side of the toe. The medial branch communicates with the medial plantar nerve and supplies the skin over the fourth interdigital cleft.
The ''deep branch'' supplies the 2nd, 3rd, and 4th
lumbricals, first and second plantar interossei and
adductor hallucis.
Clinical significance
Damage to the tibial nerve is rare, and is often a result of direct trauma, entrapment through narrow space or
compression for long period of time. Damage results in loss of plantar flexion, loss of flexion of toes and weakened inversion (The tibialis anterior can still invert the foot).
See also
*
Sciatic nerve
The sciatic nerve, also called the ischiadic nerve, is a large nerve in humans and other vertebrate animals. It is the largest branch of the sacral plexus and runs alongside the hip joint and down the right lower limb. It is the longest and widest ...
*
Tarsal tunnel
The tarsal tunnel is a passage found along the inner leg underneath the Malleolus, medial malleolus of the ankle.
Structure
The roof of the tarsal tunnel is formed by the Flexor retinaculum of foot, flexor retinaculum of the foot. The floor of th ...
*
Tarsal tunnel syndrome
*
Sural nerve
The sural nerve ''(L4-S1)'' is generally considered a pure cutaneous nerve of the posterolateral leg to the lateral ankle. The sural nerve originates from a combination of either the sural communicating branch and medial sural cutaneous nerve, ...
*
Plantar nerve
*
Medial calcaneal branches of the tibial nerve
Additional images
File:Tibial nerve.jpg, Tibial nerve
File:Gray440_color.png, Cross-section through middle of left calf
File:Gray826and831.svg, Cutaneous nerves of the right lower extremity. Front and posterior views
File:Gray834.svg, Diagram of the segmental distribution of the cutaneous nerves of the sole of the foot
File:Sacral plexus schematic.svg, A schematic of the sacral plexus with the origin of the tibial nerve shown (labeled at the bottom left)
File:Tibial and fibular nerve.jpg, Tibial nerve
File:Slide5i.JPG, Tibial nerve
File:Slide6j.JPG, Tibial nerve
References
External links
*
{{Authority control
Nerves of the lower limb and lower torso