Plantar Lateral

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).

There are variations in the thickness of the epidermis and dermis within species in different regions of the body (Table 35.1). Skin is the thickest over the dorsal and lateral surfaces of limbs, and thinner on the ventral and medial surfaces of limbs. The back (thoracolumbar lumbar junction) is usually thicker than the abdomen. In areas possessing high hair density, the epidermis is thin whereas in glabrous areas such as mucocutaneous junctions, the epidermis is thicker. The palmar and plantar surfaces consist of extremely thick stratum corneum because it is an area where abrasive action occurs. 

A 55-year-old man developed confusion, behavioral change, aggression, poor attention, disorientation in time, and impaired short-term memory. He had full ocular movements with no nystagmus, brisk deep tendon reflexes, and bilateral extensor plantar responses. He became progressively drowsy with myoclonic jerks and died 2 weeks later. 

A 36-year-old man with a history of substance abuse became unresponsive, with his eyes in mid-position gaze, with pinpoint pupils, brisk deep tendon reflexes, and bilateral extensor plantar responses. On day 9 he spontaneously opened his eyes. However, he died 1 month later with persistent pyrexia from methicillin resistant Staphylococcus aureus. 

Skin is usually thickest over the dorsal surface of the body and on the lateral surfaces of the limbs. It is thin on the ventral side of the body and medial surfaces of the limbs. In regions with a protective coat of hair, the epidermis is thin in nonhairy skin, such as that of the mucocutaneous junctions, the epidermis is thicker. On the palmar and plantar surfaces, where considerable abrasive action occurs, the stratum corneum is usually the thickest. The epidermis may be smooth in some areas but has ridges or folds in other regions that reflect the contour of the underlying superficial dermal layer (Monteiro-Riviere, 1998). 

A woman stopped taking iproniazid 50 mg twice daily and about a day and a half later became restless and incoherent almost immediately after being given pethidine 100 mg for chest pain. She was comatose within 20 minutes. An hour after receiving the injection she was flushed, sweating and showed Cheyne-Stokes respiration. Her pupils were dilated and unreactive. Deep reflexes could not be initiated and plantar reflexes were extensor. Her pulse rate was 82 bpm and blood pressure 156/110 mmHg. She was reusable within 10 minutes of receiving an intravenous injection of prednisolone hemisuccinate 25 mg. A very similar reaction was described in another patient. ... 

These fractures are typically subdivided into three types depending on their location. Zone 1 is the cancellous tuberosity, which includes the insertion of the peroneus brevis and abductor digiti minimi tendons and the lateral cord of the plantar fascia. Zone 2 is the distal aspect of the tuberosity and includes dorsal and plantar ligamentous attachments to the fourth metatarsal. Zone 3 comprises the zone distal to the ligamentous attachments to the mid-diaphyseal area. 

There are typically two sesamoids located on the plantar aspect of the head of the first metatarsal. The medial sesamoid is usually larger than the lateral. On occasion it can he bipartite and should not be mistaken for fracture. 

A 74-year-old man with chronic myeloid leukemia took imatinib mesylate 400 mg bd. His other medications were perindopril and ator-vastatin. After 2 months he developed angio-edema, probably related to perindopril, which was withdrawn and replaced by amlodipine 10 mg/day. After 2 weeks he developed typical symptoms of imatinib toxicity nausea, marked periorbital, and ankle edema. Diuretics improved the edema, but after 10 days he complained of numbness of the chin and bilateral pain and numbness in the soles of the feet. Light touch and vibration sense were reduced, but power and reflexes were intact. Imatinib was reduced to 400 mg/day and amlodipine was withdrawn. The edema, numbness and neuropathic pain resolved. Despite residual plantar numbness he was able to increase the dose of imatinib to 600 mg/day without worsening symptoms. About 1 month later he took two doses of amlodipine in error and developed nausea and palpitation, which resolved when the amlodipine was withdrawn. Nerve conduction testing 1 month later showed a mild sensorimotor axonal neuropathy. After 9 months the neuropathy had resolved despite continuing imatinib therapy. 

In rats, the skin injuries are the most prominent. They start with a scaly dermatitis involving first the dorsal and later the plantar aspects of the hind legs. The dermatitis later spreads to the forelimb, the nose, the ear, and other areas. The skin lesions are characterized histologically by the development of hyperkeratosis and acanthosis of the epithelial layers, with vasodilatation and edema of the corium. 

Dorsiflexion and plantar flexion of the ankle automatically create motion in both tibiofibular joints. Dorsiflexion causes the lateral malleolus to move laterally, to move vertically in a cephalad direction, and to rotate medially. This causes the superior tibiofibular joint to move in an upward posterior direction while rotating medially. The reverse occurs in plantar flexion. 

Examination There was bilateral ptosis, rmld bifacial weakness (can t whistle a snarl-type of horizontal smile), diplopia, especially on lateral gaze to each side (attribntable to bilateral sixth-nerve weakness) and, as part of the clinical exam, definite difficulty swallowing water. He was short of breath and vital capacity was very low at 1.2 L. There was also moderate proximal weakness in the upper limbs, and hip flexors these worsened with briefly repetitive maximal effort. Sensory examination was normal. Tendon reflexes were slightly brisk throughout (as is usual in MG), and both plantar responses were flexor. 

Examination She is moderately obese, 90 kg, and has osteoarthritis affecting the wrists. There is decreased sensitivity to pinprick and touch in the median nerve distribution of both hands, i.e., the lateral half of the palm and the ventral thumb, and index and middle fingers. TineTs and Phalen s are positive. There is moderate weakness of the oppo-nens and flexor muscles of the both thumbs. There was no weakness proximal to the wrists or in the lower Umbs. Tendon reflexes were normal, plantar reflexes were flexor. 

One channel Ankle plantar-flexion Lateral/ Medial gastrocnemius... 

Fig.l6.6a,b. Peroneal tendons, a Photograph of the lateral aspect of the ankle in a girl with her foot plantar flexed and inverted showing the main surface features (arrows) of the peroneals at the distal calf and around the lateral malleolus (LM). b Lateral view of a gross dissection of the ankle illustrates the relationship of the peroneus longus tendon (pi) with the lateral malleolus (LM). Note that the peroneus brevis is not apparent because it is covered by the peroneus longus. A fibrocartilaginous lip (arrowheads) can be appreciated at the site of attachment of the superior peroneal retinaculum onto the lateral malleolus... 

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... 

Clinical features include limited plantar flexion of the foot compared with that of the nonaffected side and posterior ankle pain exacerbated hy plantar and dorsal flexion of the foot, anterior to and not involving the Achilles tendon. Bony abnormalities in this area, and especially at the level of the posterior talus, may predispose to this syndrome. From the anatomic point of view, the posterior aspect of the talus has two tubercles, the medial and the lateral tubercle, between which the osteofibrous tunnel of the flexor hallucis longus tendon lies. In the ossification process of the... 

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... 

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