Background
Ankle Instability
Quick Screening of Ankle Function
Gait Clues
Draw Sign
Talar Slide Test
Lateral-Medial (Eversion-Inversion) Stability
Tests
Postural Distortions of the Ankle and Foot
Effects of Chronic Ankle Pronation
Commentary
Ankle Trauma
Contusions
Peroneoextensor Spasm
Disorders of the Deep Peroneal Nerve
Achilles Tendon Injuries
Ankle Strains
Special Concerns with Runners
Trigger Point Syndromes of the Ankle Area
Ankle Sprains
Subtalar Arthritis
Kohler's Disease
Talar Osteochondritis Dissecans
Tarsal Tunnel Syndrome
Posttraumatic Spurs and Related Disorders
Bowler's Spurs
Football/Soccer Ankle
Postural Distortions
In-Toeing
Out-Toeing
Miscellaneous Circulatory Disturbances
Circulatory Insufficiency Screening Tests
Edema
Volkmann's Ischemic Contracture of the Foot
Erythromelalgia
Black Heel
Tennis Toe
Articular Therapy
Clinical Features
Management
Foot Trauma
Heel Injuries
Bursitis
Foot Bruises and Wounds
Plantar Strains
Foot Sprains
Toe Sprains
Exostoses
Heel Spur
Metatarsalgia
Plantar Neuroma
Selected Disorders of Toes
Flat Foot (Pes Planus)
Ankle Fixations
Ankle Subluxations
Foot Fixations
Foot Subluxations
Toe Fixations and Subluxations
The lower leg, ankle, and foot work as a functional unit. Total body weight above is transmitted to the leg, ankle hinge, and foot in the upright position, and this force is greatly multiplied during locomotion. Thus, the ankle and foot are uniquely affected by trauma and static deformities infrequently seen in other areas of the body.
Fracture of the talus and cuboid are next in frequency to those of the calcaneus. Bilateral films are helpful to rule out a trigonum, the posterior extension of the talus occasionally occurring as a separate bone. Another anatomical variation that sometimes leads to interpretative error is a separate ossification center at the base of the fifth metatarsal (usually bilateral).
Fractures also commonly occur in the posterior or midportion of the talus. These areas may be the sites of avascular necrosis, viewed as a lucent crescent under the articular margin of the talus. In advanced cases, the superior portion of the talus may show collapse of its articular margins. This is best seen on an A-P view because overlapping malleoli cloud the picture in lateral films.
An examiner should not confuse a sharp or rough-edged fracture fragment at the posterior talus with a rounded-edged accessory ossicle (os trigonum). Fractures secondary to impact of the talus are oblique and frequently comminuted, while those secondary to ligamentous avulsion are typically horizontal. The obliquity of the fracture line is determined by the direction of force. As little as 1 mm of lateral displacement reduces the area of tibial-talar contact by 42%.
Classification of Ankle Fractures
The patterns of ankle injuries can be classified according to direction of primary and secondary forces such as external rotation, abduction, adduction, and vertical compression.
External Rotation Injuries. The common mechanism involved in ankle injury is traumatic external rotation plus abduction. The classic fracture here is an oblique fibular line directed from the anterior-inferior to the posterior-superior aspect that is frequently comminuted along the posterior cortex. Excessive foot pronation is the usual mechanism, associated with a deltoid tear. The interosseous ligaments are usually spared if the foot is in supination rather than pronation. An oblique transverse fracture of the medial malleolus at or beneath the tibial articular surface may occur, with fragments displaced inferiorly by the pull of the deltoid ligament and tearing of the anterior tibiofibular ligament. A small posterior malleolar fracture may result from the rotating fibula.
Abduction Injuries. An abduction fibula fracture is typically oblique and short. Comminution of the lateral cortex is usually related. As with external rotation injuries, abduction injuries produce transverse malleolar fractures or deltoid tears. This fibula fracture usually occurs below or within the syndesmosis but may occur above the syndesmosis if it ruptures. When external rotation is a secondary force added to abduction, the fracture is usually higher on the fibula and/or more oblique. In abduction injuries, the lateral fibular cortex may be comminuted, small dorsal tibial and fibular avulsions may be noted, and diastasis is more common because the syndesmosis is ruptured. A horizontal fracture of the medial malleolus, a torn deltoid, a high fibula fracture, and a complete rupture of the syndesmosis (called a Dupuytren fracture-dislocation) are unstable injuries resulting from forceful abduction and lateral rotation.
Adduction Injuries. Adduction ankle injuries usually result in distal fibular horizontal fractures at or below the articular surface. Frequently associated is a vertical fracture of the medial malleolus projecting above the articular surface that is often related to a fracture of the lateral aspect of the talar dome. Diastasis is not typically associated with adduction injuries, but posttraumatic arthritis may result from comminution of the articular surface. Fractures to the posterior margin are not common.
Vertical Compression Injuries. Vertical compression injuries are subdivided by Dalinka into posterior marginal fractures, anterior marginal fractures, and supramalleolar fractures.
-- Anterior marginal fractures. This type of fracture, frequently isolated, may be comminuted. It usually occurs in the dorsiflexed foot.
-- Posterior marginal fractures. These types of fractures may occur (1) with significant vertical compression of the articular margin or (2) without vertical compression. External rotation injuries, with or without an abduction factor, may produce small posterior marginal fractures. Vertical compression with external rotation force is more likely to produce large fragments. When the posterior articular fragment is large, the incidence of posttraumatic arthritis and chronic instability is high. Posterior marginal fractures seldom occur as isolated injuries; thus the proximal fibula must also receive careful evaluation. Rips of the anterior tibiofibular ligament are frequently associated.
-- Supramalleolar fractures. This type of fracture, invariably associated with fracture of the fibula, is of the distal 4 cm of the tibia above the ankle line (Malgaine fracture). It is commonly open, severely comminuted, and related to high-impact forces in the direction of axial compression.
Fatigue Fractures of the Foot
March fractures are characterized by point tenderness and sometimes, if old, a palpable callus. The onset of symptoms may be rapid or gradual. Diagnosis is made early by exclusion and late by roentgenographic findings. The condition is not common to athletes but is occasionally found in unconditioned joggers who run on hard surfaces. The second metatarsal is the site of the most common fatigue fractures found in the foot. Various congenital or acquired factors such as Morton's toe, warts, and bunion may be the underlying factor in symptomatic runners. Management is similar to that for metatarsalgia: rest and support.
Stress Cysts of the Foot
Bowerman points out that chronic stress of the talus may produce marginal degenerative cysts, similar to those seen in other weight-bearing joints (eg, knee, hip). Usually, but not always, the joint space near the cyst will be narrowed.
Normal ankle and foot movements use a combination of (1) ankle dorsiflexion (20° ) and plantar flexion (50° ), (2) subtalar inversion (5° ) and eversion (5° ), (3) midtarsal forefoot adduction (20° ) and abduction (10° ), and (4) toe flexion (45° ) and extension (80° ). When the ankle is stabilized, the major joint motions of the foot are pronation, supination, toe dorsiflexion, and toe plantar flexion. Muscles controlling the ankle, foot, and toes are shown in Table 1.
Table 1. Muscles of the Ankle, Foot, and Toes
Muscle
Major Functions
Spinal Segment
THE ANKLE AND FOOT
Extensor digiti longus
Dorsiflexion
L4-S1
Extensor hallucis longus
Dorsiflexion
L5-S1
Flexor digiti longus
Plantar flexion, foot inversion
L5-S1
Flexor hallucis longus
Plantar flexion
L5-S2
Gastrocnemius
Plantar flexion
S1-S2
Peroneus brevis, longus
Plantar flexion, foot eversion
L5-S1
Peroneus tertius
Dorsiflexion, foot eversion
L4-S1
Plantaris
Plantar flexion
L5-S1
Soleus
Plantar flexion
S1-S2
Tibialis anterior
Dorsiflexion, weak foot inverter
L4-L5
Tibialis posterior
Plantar flexion, foot inversion
L5-S1
THE TOES
Abductor digiti quinti
Small toe abduction
S1-S2
Adductor hallucis
Hallux adduction-flexion of great toe
L5-S2
Dorsal interossei
Abduction-flexion of toes 2-4
S1-S2
Extensor digiti brevis
Toe extension
L5-S1
Extensor digiti longus
Toe extension of lateral four toes
L4-S1
Extensor hallucis longus
Hallux extension
L5-S1
Flexor digiti
Flexion of lateral toes
L5-S2
Flexor hallucis brevis
1st metatarsophalangeal flexion
L5-S1
Flexor hallucis longus
Hallux flexion
L5-S2
Interossei
1st metatarsophalangeal flexion
S1-S2
Lumbricales
Flexion of toes
L5-S2
Plantar interossei
Abduction-flexion of lateral three toes
S1-S2
Quadratus plantae
Assist flexion of lateral four toes
S1-S2
Note: Spinal innervation varies somewhat in different people. The spinal nerves listed here are averages and may differ in a particular patient; thus, an allowance of a segment above and below those shown should be considered.
Descriptors of foot motion have yet to be standardized. Most authorities, however, use the following terminology: Plantar flexion and dorsiflexion are motions about a horizontal axis (through the ankle) that lies in the frontal plane. Eversion occurs about an axis running in the A-P direction of the foot. Adduction occurs around a vertical axis. Pronation refers to combined dorsiflexion, eversion, and abduction of the foot; and supination is the result of combined plantar flexion, inversion, and adduction of the foot.
Dorsiflexion and Plantar Flexion. To passively test ankle dorsiflexion and plantar flexion, firmly stabilize the heel and hindfoot with one hand and grip the forefoot with the other hand. Then push the foot into dorsiflexion and plantar flexion with the active hand. Ligament shortening, pain, or swelling commonly restricts passive manipulation of the ankle.
Subtalar Inversion and Eversion. In testing passive subtalar inversion and eversion, stabilize the distal end of the tibia with one hand and firmly grip the heel with the active hand. Alternately invert and evert the heel. Again, pain during this maneuver suggests subtalar arthritis.
Forefoot Pronation and Supination. To passively test forefoot inversion and eversion, stabilize the heel and ankle with one hand and grip the forefoot firmly in the active hand. Manipulate the forefoot medially and laterally to test passive range of motion of forefoot adduction (supination) and abduction (pronation).
Flexion and Extension of the Toes. When evaluating toe flexion and extension, first gently test the great toe. To test motion of the 1st metatarsophalangeal joint, stabilize the foot with one hand while the active hand flexes and extends a particular joint. Fixation in this joint frequently produces a protective gait restricting push-off. Flexion is the only motion of the great toe's proximal interphalangeal joint. In the lesser toes, flexion and extension occur at the proximal and distal interphalangeal joints and the metatarsophalangeal joints.
Restricted extension of the proximal and distal interphalangeal joints and restricted flexion of the metatarsophalangeal joints are features of claw toes. Restricted flexion of the distal interphalangeal joint and metatarsophalangeal joint with restricted extension of the proximal interphalangeal joint are features of a hammer toe.
KINESIOLOGY OF THE ANKLE AND FOOT
Slight intermittent muscle action is involved to control normal body sway. This minimal action is necessary because body weight does not fall through the center of the joint but slightly anterior to the center.
Dorsiflexion
Dorsiflexion is provided by the tibialis anterior (L4--L5), extensor hallucis longus (L5--S1), peroneus tertius (L4--S1), and extensor digitorum longus (L4--S1). All are supplied by the deep peroneal nerve. Test tibialis anterior strength by applying increasing resistance when the patient attempts to dorsiflex and invert his foot. It is helpful to palpate the tibialis anterior muscle with the stabilizing hand. Test strength of the extensor hallucis longus by resisting active dorsiflexion of the great toe with increasing pressure on the nail.
Ankle Dorsiflexion Test for Contractures. Limitation of the gastrocnemius or soleus muscle restricting ankle dorsiflexion can be differentiated by the ankle dorsiflexion test. Have the patient sit on the examining table with his knees flexed and relaxed. Grasp the foot and flex the knee to slacken the gastrocnemius, then dorsiflex the ankle. If this can be achieved, the gastrocnemius is the cause of the restriction. If the soleus is at fault, it will not be affected by knee flexion; ie, it will be the same in either knee flexion or extension.
Plantar Flexion
Plantar flexion is provided by the peroneus longus and brevis (L5--S1), gastrocnemius (S1--S2), soleus (S1--S2), flexor hallucis longus (L5--S2), flexor digitorum longus (L5--S2), plantaris (L5--S1), and tibialis posterior (L5--S1). The peroneus longus and brevis are innervated by the superficial peroneal nerve, all the rest by the tibial nerve. To test the peronei, oppose plantar flexion and eversion of the foot. Palpate with the stabilizing hand the first two tendons posterior to the lateral malleolus.
Toe Flexion and Extension. Flexion of the toes is controlled by the dorsal interossei, flexor digiti, interossei, plantar interossei, lumbricals, quadratus plantae, adductor hallucis, and flexor hallucis brevis and longus. Extension of the toes is governed by the extensor digiti brevis and longus, and the extensor hallucis longus.
Strength of the Great Toe. Test the strength of the flexor hallucis longus by opposing flexion of the great toe; that of the flexor digitorum longus by offering resistance to curling toes in flexion. Resistance to plantar flexion and inversion tests the strength of the tibialis posterior muscle.
Palpate the dome of the calcaneus from above plantarward. Examine the area of the medial tubercle lying on the medial plantar surface of the calcaneus, and check for spurs in adults or signs of epiphysitis in children. Heel bruises are seen affecting the plantar surface of the os calcis. This is especially common in track where the shoes are often heelless, flexible, and ultrathin (eg, long-distance runners, jumpers, hurdlers). Prolonged stress from heavy heel landings displaces the fat pad and ruptures the fibrous septa under the calcaneus. The area will be tender and often feel thick and boggy.
Heel cups are helpful in prevention and during healing. Chronic cases, often leading to spurs, may require surgical excision of new bone, necrotic fibers, and granulation tissue.
Runner Fascitis. A common cause of heel pain in runners is plantar fascitis. This is an inflammatory reaction caused by prolonged dynamic traction of the plantar aponeurosis, especially at fiber insertions into the calcaneus. This usually long-term stretch of the fascia can result in pain and chronic inflammatory reactions leading to heel spurs. A pronated ankle is often involved.
Bursitis
Palpate the area of the retrocalcaneal bursa located between the anterior surface of the Achilles tendon and the top of the heel. Lift the skin away from the tendon with one hand while palpating anterior to the tendon. Then check the calcaneal bursa situated between the insertion of Achilles tendon and the skin. Both of these bursae are subject to inflammation from pressure or friction from poorly fitting shoes (especially football shoes with their heavy counters). Special care must be taken not to confuse heel bursitis with avulsion of the Achilles insertion.
Management. Treat as any bursitis. During nonactivity, heelless sandals or slippers are recommended. During activity, low-cut shoes and heel padding throughout the counter area are recommended to avoid recurrent swelling.
Foot Bruises and Wounds
Initial treatment must be quick to minimize bleeding and swelling through cold, compression, elevation, and rest. Padding, often specially designed, should be worn as long as tenderness persists. During recovery, mobilization, local heat, ultrasound, and deep vibromassage may be applied to relieve related soreness.
Contusions and Abrasions. Most foot contusions can be traced to a dropped object, foot stubs, or cleat wounds. A blow to the lateral ankle occasionally dislocates the peronei tendons anteriorly from their normal position behind the malleolus.
Bone Bruises. A bone bruise affecting the 2nd or 3rd metatarsal head, and sometimes the transverse arch, is called a "stone bruise" in athletics. It is common in track and the result of running with full weight onto some small, hard object without adequate protection.
Puncture Wounds. A puncture wound of the sole of the foot presents a special problem. In spite of proper care, some may develop cellulitis, osteomyelitis, tetanus, or acute arthritis of the foot. With early suspicions, referral should be made for debridement and/or antibiotics.
Plantar Strains
The strong bands of plantar fascia have their origin at the medial tubercle of the calcaneus, spray across the sole, and insert near the metatarsal heads. Tight plantar fascia raises the longitudinal arch. During palpation, the plantar aponeurosis should feel smooth and without areas of tenderness.
True plantar fascitis is rare, but when it occurs, it is often confused with sprain of the spring ligaments in the arch. It is usually the result of chronic pronation, fascial tears from dorsiflexion overstress, or associated with calcaneal fatigue fractures.
Clinical Features. The typical clinical picture of plantar strain primarily exhibits pain during running due to plantar-fascial stretch. Tenderness is found just distal to the calcaneal tubercles. Palpable stiff cords or nodules within the fascia suggest consequences of chronic plantar fascia spasm, Dupuytren's contractures tender under deep pressure, or plantar warts tender to pinching. Some degree of swelling may be felt. Callosities, like contractures, are tender to pressure but not to pinching. In acute cases, a slight degree of ecchymosis and severe tenderness may be at attachments, especially on the heel. Early roentgenographs are negative, but calcification may appear on later films.
Management. Check thoroughly for possible cuboid or navicular subluxation. Adjunctive care consists of cold packs during elevation and compression, which are later followed by vibromassage, trigger point therapy, contrast baths, and ultrasound. A temporary longitudinal arch support (or taping) and crutches are helpful during initial healing. Chronic low arches do not seem to be a precipitating factor.
Foot Sprains
Calcaneocuboid Sprain. Calcaneocuboid sprain is usually produced by forceful internal rotation of the foot on the talonavicular joint when the foot is inverted. There is immediate severe pain, swelling over the calcaneocuboid area, and great disability. This can be a chronic strain that can set up a subtle pathobiomechanical complex, extending for many years, with distal neurologic effects.
Rearfoot Sprain. Rearfoot sprains are usually chronic in nature, featuring progressive pain with minimal swelling in the rear half of the foot during and following activity. Talar subluxations and restrictions are often related. The cause in some cases can be traced to a low-grade tarsal synovitis from poor foot support on hard ground during strenuous activity.
Spring Ligament Sprain. Overstress of the plantar calcaneonavicular ligament is often associated with navicular subluxation. Symptoms of medial aching pain and tenderness deep within the plantar arch commonly arise after prolonged running when soft shoes are worn. Differentiation must be made from plantar fascitis, which is found farther posterior and usually more acute.
Forefoot Sprain. An ache and tenderness under the 2nd and 3rd metatarsal heads are often the result of postural stress. As a consequence of severe eversion or inversion strain, avulsion of the insertion of the tibialis posterior features acute styloid tenderness.
Management. Correct any fixation-subluxations isolated and apply general sprain management with emphasis on rest, contrast baths, and ultrasound in water. During rehabilitation, arch strapping, passive mobilization of the entire foot, intrinsic exercises, and orthotics improving foot support are helpful.
Toe Sprains
The most common toe sprain is that of the great toe, especially at the metatarsophalangeal joint as the result of forced plantar flexion or dorsiflexion. Sideward sprains rarely occur. Pain and swelling may be severe, but bone tenderness or crepitus is absent. Disability is severe because weight-bearing is predominantly on the hallus. Sprains of the other toes are managed similar to finger sprains.
Exostoses
Bony overgrowths infrequently form at the head of a metatarsal, especially the 1st metatarsal. Treatment is usually by surgery (exostectomy). However, what may appear to be a bony overgrowth during palpation (a knuckle-like prominence) is actually a metatarsocuneiform subluxation that can be demonstrated by roentgenography.
Heel Spur
A heel spur typically forms at the inferomedial aspect of the calcaneus. The cause is attributed to chronic traction of the plantar fascia on calcaneal periosteum. The clinical picture includes a distinct limp, constant pain only during weight bearing, tenderness increased in dorsiflexion, and mild swelling along the medial aspect of the os calcis or plantar fascia attachments at the calcaneal tuberosity.
Management. Minor conditions can be aided by heel pads and any taping procedure that supports the arches of the foot. Surgery is reported to be the treatment of choice, but trauma from the surgery may set the stage for further periosteal reactions and other surgical complications.
Metatarsalgia
Morton's syndrome (metatarsalgia) produces pain near the proximal end of one or more of the three outer toes. It is especially debilitating in track and almost always associated with compression of the foot by tight shoes pinching the external plantar nerves between the metatarsal bones.
Signs and Symptoms. An osseous triad consists of (1) a 1st metatarsal bone that is shorter than the 2nd, (2) hypermobility at the naviculocuneiform and medial-and inter-cuneiform articulations, and (3) posteriorly displaced sesamoids. In addition, there are toe pain, foot fatigue, and pronation complaints that are often associated with plantar callous patterns, bunion, corns, and intermetatarsal neuroma. There also is hypertrophy of the 2nd metatarsal joint, the foot is pronated and the arch flattened, and there is abnormal weight balance and distribution. Differentiation must be made from postural strains, neuroma, march fractures, subluxations, exostoses, and tendon avulsions.
Morton's Test. In metatarsalgia, transverse pressure across the heads of the metatarsals induces sharp pain, especially between the 2nd and 3rd metatarsals.
Strunsky's Test. This test is designed essentially for the recognition of lesions of the metatarsal arch. Under normal conditions when the toes are grasped and quickly flexed, the procedure is painless. Pain results if there is an inflammatory lesion in the metatarsal arch.
Management. Use a shin splint taping procedure in acute cases. After mobilizing all fixated joints from the foot to the hip, adjunctive care includes ultrasound in water, deep vibromassage (many trigger points will be found), padding beneath the tongue of the shoe, and transverse arch support. A metatarsal crescent can be applied to the sole of the shoe or a felt pad placed just behind the plantar metatarsal heads involved. In either case, the object is to slightly lift the stressed joints during weight bearing. The patient should be advised to lace the foreshoe loosely. Graduated tiptoe walking and walking on the lateral edge of the foot are helpful during rehabilitation. Poorly responding cases may require referral for specialized attention.
Plantar Neuroma
A rare cause of metatarsalgia is Morton's neuroma --painful round "beads" found between the heads of the 1st through 4th metatarsals, especially between the 3rd and 4th. They are thought to be the effect of excessive foot rolling where the plantar nerve is chronically impinged on taut fascia or bone. Hypertrophy of the nerve sheath develops, and there is an accompanying digital artery disorder. Shooting distal pains and sometimes periods of numbness are severe but quickly relieved when the shoeless foot is rested. Roentgenographs are negative. The disorder is rare in athletics but must be differentiated from postural strains and tendon avulsions producing forefoot pain and plantar tenderness.
Selected Disorders of Toes
Bunion. A bunion is a progressive effect of prolonged hallux valgus where the great toe displaces laterally with rotation about the long axis so that the nail faces medially. The sesamoid enlarges, and the soft tissues on the lateral aspect of the great toe enlarge. An adventitious bursa forms that often becomes tender and inflamed.
Whenever a bunion is found, check the ankle for hyperpronation. Bunions are especially common in hyperpronated runners and women who habitually wear sharp-pointed shoes. Increased pronation causes a lax peroneus longus tendon, which attaches to the first metatarsal and typically exerts a lateral pull. This laxity from hyperpronation allows the metatarsal to adduct. Shoe irritation and concomitant bursal inflammation produce the painful bunion.
Claw Toes. Claw toes, usually associated with pes cavus, feature flexed proximal and distal interphalangeal joints and hyperextended metatarsophalangeal joints. An early sign is the formation of callosities over the dorsal surface of the toes, on the tips of the toes, and on the plantar surface under the metatarsal heads.
Check for short shoes. Shoe salesmen often measure foot length in nonweight-bearing, which is ridiculous.
Hammer Toe. A hammer toe presents fixed flexion of the proximal interphalangeal joint with hyperextension of the metatarsophalangeal and distal interphalangeal joints. It is usually singular and associated with a callosity on top of the proximal interphalangeal joint. Predisposing factors include forceful plantar flexion of the metatarsal joint, pes cavus, a short metatarsal, forefoot valgus, trauma, or pronation imbalance.
Mallet Toe. A mallet toe is a distal interphalangeal joint flexion contracture that usually occurs in the smaller toes. It is less common than a hammer toe.
Sesamoiditis. Deep palpation within the flexor hallucis brevis tendon may locate the two sesamoids where signs of sesamoiditis develop. Sesamoid necrosis under the head of the 1st metatarsal in the flexor hallucis longus tendon may show roentgenographic signs. Passive mobilization of fixated joints, adjustment of subluxations, strapping, rest, ultrasound in water, sole padding, and improved footwear are beneficial. Progressive exercises may be started immediately after the acute stage has subsided.