Plantar Nerve

The nerve fibers most vulnerable to -hexane exposure in rats were the branches of the tibial nerve serving the calf muscles of the hind limbs, followed in order by the plantar nerve branches supplying the flexor digitorum brevis muscle, and then sensory plantar nerve branches innervating the digits. As... 

Fig. 20.10. The muscles of the lower hind limb in cross-section. In this image, anterior is down and medial is left. Abbreviations are as follows MG, medial gastrocnemius LG, lateral gastrocnemius Plant, plantaris PN, plantar nerve Sol, soleus Fib, fibula EDL, extensor digitorum longii TA, tibialis anterior Tib, tibia. The mouse muscles are predominantly fast muscle fibers, but the soleus is valuable for its high percentage of slow fibers. Note, the darker mass on the posterior portion of the leg is a lymph node that provides a convenient landmark when sectioning to establish that reproducible sections are examined in the proximal/distal axis. Also, the peripheral muscles in the section are the hamstrings, which insert along the tibia in the lower leg in the mouse. (Color figure is available online).

In thiamin-deficient rats, electron microscopy of the sciatic and plantar nerves shows distally pronounced axonal degeneration, with an increase in the number of mitochondria and proliferation of vesicular elements of the endoplasmic reticulum. This is followed by disintegration of neurotubules and neurofilaments, and finally axonal shrinkage and myelin disruption (Pawlik etal., 1977). 

Massicotie, C., Barber, D. S., Jortner, B. S., and Ehrich, M. (2001). Nerve conduction and ATP concentrations in sciaiic-tibial and medial plantar nerves of hens given phenyl saligenin phosphate. NeumToxicology 22, 91-98. 

Morton s neuroma is a plantar digital neuroma of the third branch of the median plantar nerve on the foot resulting in a burning pain of the foot. The injection relieves the burning and pain, but it does cause edema and pain at the injection site. Elevating the foot and applying ice will address the acute discomfort associated vrith the injection. 

At the medial ankle, the tibial nerve, a continuation of the medial trunk of the sciatic nerve, passes deep to the flexor retinaculum in the space between the medial malleolus and the medial wall of the calcaneus (Fig. 16.10a). The retinaculum consists of a thin fascia and forms the roof of the tarsal tunnel (Fig. 16.10). In addition to the nerve, the tarsal tunnel encloses the tibialis posterior, flexor digitorum longus and flexor hallucis longus tendons, the posterior tibial artery and two veins (Fig. 16.10a,b). Posteroinferior to the medial malleolus, the tibial nerve divides into the medial and lateral plantar nerves and the calcaneal nerve, which is responsible for the sensitive supply of the heel (Fig. 16.11). The plantar nerves supply the intrinsic foot muscles, except for the extensor digitorum brevis, which is innervated by the deep peroneal nerve. The posterior tibial artery accompanies the nerve deep to the flexor retinaculum and, inferior to the medial malleolus, it divides into medial and lateral plantar arteries (Fig. 16.11). 

Fig.16.11. Normal tibial nerve at the tarsal tunneL Gross dissection of the tarsal tunnel gives a closer look to the tibial nerve (arrows) and its divisional branches, the medial (1) and lateral (2) plantar nerves, and the calcaneal branches (arrowheads), a, posterior tibial artery. The insert on the left of the figure indicates the site of the anatomic specimen illustrated...

Fig. 16.30 a,b. Normal tarsal tunnel, a Transverse 12-5 MHz US image obtained posterior to the medial malleolus (MM) demonstrates the tibial nerve (arrow) located close to the posterior tibial artery (a) and veins (v) and posterior to the tibialis posterior (tp) and flexor digitorum longus (fdl) tendons. All these structures lies in the tarsal tunnel and are covered by the flexor retinaculum (arrowheads), b Oblique transverse 12-5 MHz US scan at the medial heel shows the medial and lateral plantar nerves (arrows) as a result of division of the main trunk of the tibial nerve. The photographs at the upper left of the figures indicate probe positioning... 

Tarsal tunnel syndrome refers to the entrapment of the main trunk of the tihial nerve and/or of its divisional branches (medial plantar nerve, lateral plantar nerve, calcaneal nerve) at the medial aspect of the ankle. This syndrome has an insidious clinical onset with numbness or pain in the foot and ankle and paresthesias in the sole of the foot, often with the heel being spared. However, clinical and electromyographic diagnosis of tarsal tunnel syndrome is often not straightforward, especially when a soft-tissue swelling on the medial ankle is absent. Depending on the site of compression, tarsal tunnel syndrome produces different clinical syndromes that can be classified as proximal or distal. The proximal syndrome consists of entrapment of the main trunk of the tibial nerve in the... 

Lateral Plantar Nerve, Tibial Nerve, Sciatic Nerve, Ventral Division Sacral Plexus, SI, S2. 

Figure 109. Course and distribution of the sciatic, tibial, posterior tibicJ, and plantar nerves. (From Haymaker, W., and Woodhall, B. Peripheral Nerve Injuries, 2nd ed. W. B. Saunders Co., 1953.)...

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