- See:
Innerv. Musc. Lower Limb:
- Anatomy:
- tibial nerve is derived from
L4,
L5,
S1,
S2,
S3;
- the anterior component, supplies muscles of posterior thigh (except short head of biceps whch is supplied by
peroneal nerve);
- in popliteal space it gives off branches that supply
popliteus muscle, two heads of
gastrocnemius ,
soleus , &
plantaris muscles.
- nerve passes into
posterior compartment of leg to lie deep to the transverse crural septum;
- here, it supplies
tibialis posterior,
FHL , &
FDB;
- nerve passes behind medial malleolus to plantar side of foot and divides into medial and lateral plantar nerves:
-
Medial branch: counterpart of
median nerve in hand;
- innervates the first
lumbricals,
abductor hallucis,
FDB, and
flexor hallucis brevis;
-
Lateral branch: counterpart of the
ulnar nerve in the hand;
-
plantar muscles of the foot: are arranged in four layers w/ the
FDB lying most superficially, just under
plantar fascia;
- medial and lateral branches of
tibial nerve pass superficial to
abductor hallucis and
quadratus plantae (w/ exception of 1st branch of lateral plantar nerve);
- at the quadratus plantae, these nerve branches changes direction from verticle to horizontal;
-
First Branch of Lateral Plantar Nerve: (Baxter's Nerve)
- is the only branch to course deep to the
abductor hallucis and
FDB (but superficial to
quadratus plantae) as it courses
medially hugging the
medial aspect of of the calcaneus, adjacent to the heel spur, on its way to supply the quadratus, FDB, and
ADM;
- sensory component: calcaneal periosteum, the long plantar ligament and the lateral plantar skin;
- impingement of this nerve typically produces a Tinel's sign along the nerve branch deep to the abductor hallucis muscle;
- nerve passes lower border of the abductor hallucis, then courses laterally, passing 5-6 mm anterior to the medial calcaneal tuberosity (or spur)
and then courses between the quadratus and the underlying flexor brevis, and then passes to the abductor digiti minimi;
- references:
-
Treatment of chronic heel pain by surgical release of the first branch of the lateral plantar nerve. Clin Orthop Relat Res 1992;279:229-236.
-
Nerve entrapment in painful heel syndrome
- Posterior Nerve Block:
-
posterior tibial artery is palpated as a landmark;
- needle is passed adjacent to the achilles tendon toward the
posterior tibial artery behind the medial malleolus;
- after aspiration, 5 ml of anesthetic is required;
- to block posterior
tibial nerve, infiltrate just medial to achilles;
- insert the needle thru the deep fascia until it impinges on the bone behind the medial malleolus;
- Tibial Nerve Palsy:
- w/ tibial nerve palsy foot develops:
- cavus deformity due to plantar fascia contracture;
- lengthening of Achilles tendon rotating calcaneus into dorsiflexion;
- only
tibialis anterior is strong enough to produce active plantar flexion in presence of paralyzed triceps surae;
- Distal Tibial Tarsal Tunnel Syndrome:
Magnetic resonance imaging for ineffectual tarsal tunnel surgical treatment.
