Forefoot and midfoot pain in the active child or skeletally immature adolescent: Overview of causes

INTRODUCTION — An overview of the causes of forefoot and midfoot pain in active children and skeletally immature adolescents will be reviewed here.

An overview of causes of heel and ankle pain and evaluation of foot pain and injury in children are discussed separately. (See "Heel pain in the active child or skeletally immature adolescent: Overview of causes" and "Ankle pain in the active child or skeletally immature adolescent: Overview of causes" and "Foot and ankle pain in the active child or skeletally immature adolescent: Evaluation".)

ANATOMY — The foot can be divided into three functional parts: the hindfoot, midfoot, and forefoot as follows (figure 1) [1]:

●Hindfoot – The hindfoot, which consists of the talus and the calcaneus, connects to the midfoot at the midtarsal (Chopart) joint.

●Midfoot – The midfoot contains the navicular, the cuboid, and the three cuneiform bones; it connects to the forefoot at the Lisfranc joint.

●Forefoot – The forefoot includes everything distal to the Lisfranc joint, including the metatarsals, sesamoids, and phalanges.

The anatomy of the foot and the role of each functional part in the gait cycle are discussed in detail separately. (See "Foot and ankle pain in the active child or skeletally immature adolescent: Evaluation", section on 'Anatomy' and "Foot and ankle pain in the active child or skeletally immature adolescent: Evaluation", section on 'Biomechanics'.)

EVALUATION — Foot pain in the young athlete can originate in the bones (fractures), ligaments (sprains), tendons, fascia, or soft tissues. Careful history, physical examination, including evaluation of the footwear, and localization of tenderness can help to narrow the differential diagnosis (figure 2). (See "Foot and ankle pain in the active child or skeletally immature adolescent: Evaluation".)

ACUTE INJURIES — Common acute injuries in children and adolescents consist of friction blisters, wounds to the sole of the foot, stubbed toes with subungual hematoma or phalangeal fractures, and metatarsal fractures. Forced hyperextension of the first toe may cause a metatarsophalangeal joint sprain. Lisfranc complex injuries are less commonly seen but warrant prompt referral to an orthopedic surgeon with pediatric expertise.

Friction blister — Friction blisters are intraepidermal blisters that result from trauma-induced separation within the epidermis. They most frequently occur on the heels and soles of the feet due to friction from shoes and socks during walking or running. They may also occur on the toes, especially with improper fitting footwear [2]. For example, narrow shoes cause blisters on the outside portions of the great and little toes; shoes that are too big may cause blisters on the tips of the toes from the foot sliding within the shoe. Blisters can be prevented by ensuring that shoes fit properly and that socks stay dry. Socks that wick moisture away from the skin (eg, acrylic, polyester, or wool socks worn over polyester socks) also decrease the likelihood of a blister. (See "Heel pain in the active child or skeletally immature adolescent: Overview of causes", section on 'Friction blister'.)

Blisters on the ball of the foot and toes should be managed similar to blisters of the heel and depend upon the size and degree of impairment (see "Heel pain in the active child or skeletally immature adolescent: Overview of causes", section on 'Friction blister'):

●Small blisters – Small blisters that are minimally painful can be cleaned and taped as follows:

•The foot should be clean and dry at the time of tape application.

•Adhesive (eg, benzoin or adhesive spray) applied to the skin enhances tape grip.

•The tape should be applied so that wrinkles are avoided.

•The tape should be left in place as long as possible.

•When treating blisters the provider should use paper tape or similar material with a smooth outer coating so that adjacent toes do not develop skin break down or blisters [2].

●Large or painful blisters – Large or painful blisters should undergo fluid drainage while maintaining the roof of the blister as a biologic bandage as follows:

•Clean the intact blister with isopropyl alcohol or other suitable antiseptic solution.

•With a sterile needle (eg, 22 gauge), puncture the blister distally and away from the midline. Use multiple holes rather than one big hole, as needed, to fully drain the fluid but decrease the risk of unroofing the blister.

•Gently express the blister fluid until the blister is flat.

•Dry the skin over the blister and apply paper tape so that it overlaps the edge of the blister according to the blister site as follows:

-Toes: Apply one piece of paper tape longitudinally and then wrap a second piece of tape circumferentially without too much overlap. The edge of the tape should end on the dorsum of the toe to prevent irritation of neighboring toes.

-Ball of foot: Dry the skin over the blister and apply paper tape so that it overlaps the edge of the blister. Apply benzoin adhesive to the paper tape and cover it with elastic tape. Make the edges smooth.

●Unroofed (open) blisters – Open blisters should be managed as follows:

•Trim off the roof of the blister.

•Cover the base of the blister with a blister pad designed for open blisters (eg, Spenco 2^nd Skin or Band-Aid Advanced Healing Blister).

•Cover the blister pad with paper and elastic tape as described for large blisters above.

With proper treatment of blisters, children and adolescents should be able to participate in activities without restriction. Dressing should be soaked off and the blisters inspected daily until healing has occurred followed by reapplication. The caregivers should be advised to watch for signs of infection, including redness, increased pain, swelling, and pus drainage and to seek prompt medical attention if they occur.

Plantar puncture wound — Plantar puncture wounds involving the sole of the foot are a common injury. Typical objects causing these injuries include nails, pins, other metal objects, wood, stones, and glass. These wounds have a significant risk for infection. When evaluating plantar puncture wounds in children and adolescents the clinician should determine when the injury occurred, whether the patient was barefoot or wearing shoes, and what object caused the wound, if known. The wound should be examined with the patient prone and, for actively bleeding wounds, a tourniquet or blood pressure cuff applied so that the field is bloodless. (See "Infectious complications of puncture wounds", section on 'Epidemiology' and "Infectious complications of puncture wounds", section on 'Diagnosis'.)

Imaging is warranted when there is a clinical suspicion of a retained foreign body. Plain radiographs can detect many radiopaque foreign bodies (eg, glass, stones, or metallic objects). Wood, plastic, and other radiolucent objects can be located with ultrasound. Computed tomography and magnetic resonance imaging are also helpful methods of localizing a retained foreign body when plain radiographs or ultrasound fail. Magnetic resonance imaging (MRI) cannot be used when metallic objects are present. (See "Infectious complications of puncture wounds", section on 'Diagnosis'.)

The management of plantar puncture wounds depends upon the presence of infection and is discussed separately. (See "Infectious complications of puncture wounds", section on 'Management'.)

Laceration — Lacerations of the sole of the foot warrant assessment, debridement, and treatment according to the general principles of wound management. Typically, nonabsorbable sutures are used for wound closure and are kept in place for approximately 10 days. (See "Minor wound evaluation and preparation for closure" and "Skin laceration repair with sutures".)

Lacerations to the sole of the foot frequently involve cuts caused by sharp objects that the patient steps on while barefoot and foreign bodies are an important consideration. Imaging is warranted when there is a clinical suspicion of a retained foreign body. Plain radiographs can detect many radiopaque foreign bodies (eg, glass, stones, or metallic objects). Wood, plastic, and other radiolucent objects can be located with ultrasound. Computed tomography and magnetic resonance imaging are also helpful methods of localizing a retained foreign body when plain radiographs or ultrasound fail. MRI cannot be used when metallic objects are present. (See "Infectious complications of puncture wounds", section on 'Diagnosis'.)

Relative to wounds on other parts of the body, lacerations on the sole of the foot are more painful to anesthetize by local injection. A posterior tibial nerve block provides an alternative approach that may provide better pain control during the procedure. (See "Lower extremity nerve blocks: Techniques", section on 'Ankle block'.)

Lower extremity wounds are more prone to infection than lacerations with better perfusion (eg, face or scalp lacerations). Thus, patients should have a wound check within a few days of wound closure and should be given careful instructions regarding proper wound care, including no swimming, no immersion while bathing, and how to monitor for infection. (See "Skin laceration repair with sutures", section on 'Aftercare'.)

Subungual hematoma — Trauma, to the nail or nail bed (eg, blunt trauma or repetitive injury during long distance running) can result in a subungual hematoma; blood pooled beneath the nail, that can be very painful and require nail trephination. The management of acute subungual hematomas is discussed separately. (See "Subungual hematoma".)

First metatarsophalangeal joint sprain ("turf toe") — A sprain of the first metatarsophalangeal (MTP) joint (sometimes called "turf toe") typically occurs following forced hyperextension of the great toe by the ground such as an axial load to the heel of foot when it is up on its toes. Depending upon the severity of injury, there is some degree of swelling, discoloration, and tenderness around the first MTP joint. Passive extension of the great toe may be limited in the acute setting and is most painful, but severe injuries with complete disruption may have increased motion related to the lack of structural integrity. Radiographs may demonstrate a bone avulsion of the proximal phalanx/sesamoid, and if there is more than 3 mm of retraction of the sesamoid on the anteroposterior (AP) view compared with the contralateral foot, a significant plantar plate injury is likely [3]. Passive gliding of the first MTP joint in a plantar direction along the plane of the joint can be performed to assess the stability of the plantar ligament complex.

The sprain is graded as follows:

●Grade I – Sprain of the plantar capsular ligament complex that is painful but not disabling

●Grade II – Partial rupture of the plantar capsular ligament complex

●Grade III – Sprain with severe swelling and ecchymosis, weakness of great toe flexion, and instability of the first MTP joint

The management of first metatarsophalangeal joint sprain is discussed separately. (See "Evaluation, diagnosis, and select management of common causes of forefoot pain in adults", section on 'First metatarsophalangeal joint sprain ("turf toe")'.)

Lisfranc joint complex injuries — The Lisfranc joints separate the distal portion of the cuneiforms and cuboid (midfoot) and the proximal base of the metatarsals (forefoot) (figure 1). The Lisfranc ligament complex attaches the lateral aspect of the medial cuneiform to the medial aspect of the proximal second metatarsal. They may be injured when the foot is plantar-flexed and excessive weight or axial force is applied to the joint (eg, player falling onto the heel of an opponent's plantar-flexed foot) or if the forefoot is pinned and the body is pulled backwards (eg, falling backwards off a windsurfing board or horse while the foot remains in the foot strap or stirrup). (See "Tarsometatarsal (Lisfranc) joint complex injuries" and "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'Clinical anatomy' and "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'Mechanism of injury'.)

Patients typically present with swelling and pain over the proximal second metatarsal and midfoot. Palpation localizes tenderness to the tarsometatarsal region. Pain is increased with passive pronation or supination of the forefoot with the heel held stationary. While often absent in isolated tarsometatarsal (TMT) sprains, plantar ecchymosis is essentially pathognomonic for Lisfranc injuries. When a Lisfranc injury is suspected, the clinician should carefully assess the dorsalis pedis pulse and for the presence of a compartment syndrome. (See "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'History and examination findings'.)

Patients with suspected Lisfranc injuries should undergo plain radiographs, including weight-bearing anteroposterior, lateral, and oblique views. Non-weightbearing radiographs may not demonstrate the clinically important instability findings. Findings of a Lisfranc injury include the following (see "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'Diagnostic imaging' and "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'Classification of injury'):

●Avulsion fractures at the insertion of the Lisfranc ligament complex at the lateral base of the second metatarsal (also called the "fleck sign")

●Widening >2 mm between the first and second metatarsal bases (comparison view may be necessary to appreciate)

●Loss of alignment between the medial borders of the second metatarsal and the second cuneiform bones

●Loss of dorsal cortical alignment between the first metatarsal and the medial cuneiform bones

●Loss of alignment between the medial borders of the fourth metatarsal and cuboid bones

For patients with clinical findings suggesting Lisfranc injuries and normal plain radiographs or who cannot tolerate weightbearing, computed tomography (CT) or MRI of the foot is warranted.

Lisfranc injuries warrant referral to an orthopedic surgeon with pediatric expertise. The management of Lisfranc injuries is discussed in more detail separately. (See "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'Management'.)

Fracture — Most fracture of the fore- or midfoot involve the metatarsal bones. Toe fractures also occur commonly while fractures of midfoot bones are rare. However, midfoot fractures have the greatest potential for causing permanent deformity or disability. (See "Metatarsal and toe fractures in children" and "Foot fractures (other than metatarsal or phalangeal) in children".)

Children typically present for evaluation because of pain and difficulty walking. Ecchymosis and swelling are usually present and occur within the first few hours after injury. Palpation along the foot or digit frequently reveals point tenderness at the fracture site. However, the dorsum of the foot or toe may be diffusely swollen and tender, making it difficult to pinpoint the fracture location by examination alone. Of note, tenderness at the base of the fifth metatarsal after an inversion injury is highly suggestive of a fracture and may not be accompanied by significant swelling soon after the injury. With displaced fractures and dislocations, deformity is usually apparent. (See "Metatarsal and toe fractures in children", section on 'Clinical presentation and examination' and "Foot fractures (other than metatarsal or phalangeal) in children", section on 'Clinical presentation and examination'.)

In all cases, capillary refill should be assessed and the skin of the digit carefully inspected, seeking lacerations and devitalized skin. Any wound should be carefully examined to exclude communication with the fracture site (ie, an open fracture). Devitalized skin may slough and convert a closed fracture into an open one. Injury to surrounding soft tissue including the nail and nail bed can occur, particularly with crush injuries. Subungual hematoma is often a marker of an underlying distal phalanx fracture. (See "Subungual hematoma".)

Plain radiographs, with anteroposterior (AP), lateral, and oblique views of the foot, remain the most appropriate initial imaging modality and suffice to diagnose most low-energy foot fractures in children. However, patients with Salter Harris I fractures and stress fractures may initially have normal images. In rare instances, comparison views with the uninjured foot may be helpful in identifying subtle fractures. Special views may be necessary to evaluate specific midfoot fractures. (See "Metatarsal and toe fractures in children", section on 'Radiographic findings' and "Foot fractures (other than metatarsal or phalangeal) in children", section on 'Radiographic diagnosis'.)

Patients with a suspected Tarsometatarsal (Lisfranc) fracture typically warrant specialized imaging guided by an orthopedic surgeon. (See "Tarsometatarsal (Lisfranc) joint complex injuries", section on 'Diagnosis'.)

The management of fractures of the fore- and midfoot are discussed separately. (See "Metatarsal and toe fractures in children", section on 'Initial management' and "Foot fractures (other than metatarsal or phalangeal) in children", section on 'Initial management'.)

OVERUSE INJURIES — Overuse injuries include flexor hallucis longus tendinitis and tibialis posterior tendinitis. Less commonly, children and adolescents can develop plantar fasciitis and flexor digitorum longus tendinitis.

Flexor hallucis longus tendinitis/insufficiency — Flexor hallucis longus (FHL) tendinitis, sometimes called "dancer's tendinitis" is common among classical ballet dancers because the FHL is a prime stabilizer when they are on their "tip toes" (in demi-pointe). Also, runners, soccer players, and other athletes will stress this tendon when in a similar position during toe off. Patients complain of pain and tenderness at the posteromedial ankle (figure 2). The pain may also radiate distally along the medial arch and is exacerbated by weightbearing or athletic activity. FHL tendinitis is discussed in greater detail separately. (See "Non-Achilles ankle tendinopathy", section on 'Medial ankle tendinopathy' and "Ankle pain in the active child or skeletally immature adolescent: Overview of causes", section on 'Flexor hallucis longus injuries'.)

Tibialis posterior tendinitis — The tibialis posterior muscle inverts and plantar flexes the foot and supports the medial longitudinal arch during walking (picture 1 and figure 3). Stress on the posterior tibialis will increase in patients with inadequate hip strength that causes increased knee valgus and internal rotation. Patients with posterior tibialis tendinitis typically complain of pain around the posteromedial ankle. A small prominence medial to the navicular will be present in patients with a type I os tibiale externum, where the accessory ossicle is located in the posterior tibialis tendon. Swelling may be present along the course of the tendon, particularly several centimeters proximal to its insertion on the navicular. However, as the condition progresses, partial tearing of the tendon or avulsion from its insertion on the navicular can occur, and the longitudinal arch may drop resulting in a "flat foot" (pes planus). This collapse causes midfoot rotation and impingement of lateral structures. The patient may then complain of lateral ankle pain and a gradual "turning out" of the foot.

The clinical manifestations, diagnosis, and treatment of tibialis posterior tendinitis are discussed separately. (See "Non-Achilles ankle tendinopathy", section on 'Medial ankle tendinopathy'.)

Plantar fasciitis — Plantar fasciitis occurs less commonly in children and adolescents than in adults but may be seen in distance runners, dancers, and sedentary, obese children. (See "Plantar fasciitis".)

Many patients with plantar fasciitis have the "first step in the morning" symptom, in which the pain occurs for the first few minutes after getting out of bed and then resolves. This first step may be easily confused with morning stiffness associated with spondyloarthropathies. As the course of plantar fasciitis progresses, pain may return at the end of the day. The patient may report that it feels as if there is a rock in his or her shoe. The pain is lessened if the patient walks on the outside of the foot. (See "Plantar fasciitis", section on 'Common clinical features'.)

The area of maximal tenderness typically is over the medial calcaneal tubercle and, less commonly, into the arch (usually in patients with pes cavus) (figure 2). Pain is best appreciated when the great toe is passively dorsiflexed, causing the plantar fascia to become taut and easy to palpate (picture 2). Examination should also include evaluation for tight gastrocnemius and pes planus because the treatment plan may vary if these conditions are present. (See "Plantar fasciitis", section on 'Common clinical features' and 'Arch abnormalities' below.)

The diagnosis, differential diagnosis, and treatment of plantar fasciitis are discussed in greater detail separately. (See "Plantar fasciitis".)

Flexor digitorum longus tendinitis — Injuries of the flexor digitorum longus (FDL) tendon are uncommon events and can be difficult to differentiate from plantar fasciitis. The FDL tendon may become inflamed at the medial plantar aspect secondary to excessive pronation or the increased effort of plantarflexing the toes during propulsion. Dancers and other athletes involved in jumping sports are most commonly affected. FDL tendinitis is diagnosed by history and examination showing pain with resisted toe flexion (which differentiates it from plantar fasciitis). (See "Heel pain in the active child or skeletally immature adolescent: Overview of causes", section on 'Plantar fasciitis'.)

Treatment of acute FDL tendinitis consists of the following:

●Rest, cold packs, and short courses of nonsteroidal antiinflammatory drugs (eg, ibuprofen) are used during the acute phase for pain.

●Strengthening the flexor tendons of the foot and correction of other biomechanical abnormalities through physical therapy prevents injury recurrence.

●Taping to decrease toe flexion of the second through the fifth toes for up to six weeks after acute tendinitis develops.

●Toe crest pads to decrease overuse of the long flexors of the foot during toe-off. Toe crest pads are single longitudinal pads that are placed in the sulcus of the second through fifth toes distal to the metatarsal heads (figure 4); they create an upward force on the toes to decrease the degree of toe flexion and alleviate the symptoms of FDL tendinitis.

Patients who persist with pain and disability despite these measures warrant referral to sports medicine physician with pediatric expertise. Advanced diagnostic imaging, such as MRI, may be helpful in identifying less common etiologies of the problem such as an accessory flexor digitorum longus or focal pathology at the sustentaculum tali.

ARCH ABNORMALITIES — Among arch abnormalities, flexible pes planus (flat feet) is most common and typically describes functional flat feet that are physiologic and asymptomatic. Patients with painful flexible pes planus warrant evaluation for associated ligamentous laxity, tight heel cords, and tibialis posterior tendon dysfunction. Rigid pes planus (flat feet) and pes cavus (fixed high arch) warrant specialty referral to evaluate underlying abnormalities such as tarsal coalition (pes planus), neuromuscular disease (pes cavus), or talipes equinovarus (residual club foot causing pes cavus).

Rigid pes planus (flat feet) — Pes planus and flat feet are the terms used to describe feet with moderate or complete loss of the longitudinal arch. Pes planus can be classified radiographically according to the degree of depression of the lateral talometatarsal angle. However, a clinical classification can also be used for evaluation and treatment of this common condition. The clinical classification divides pes planus into two general categories: rigid and flexible. This distinction depends upon the mobility of the tarsal and subtalar joints [4].

Rigid pes planus is diagnosed when:

●Range of motion at the tarsal and subtalar joints is decreased AND

●The arch does not increase with toe raising.

These findings also may occur in tibialis posterior tendon dysfunction, tarsal coalition and peroneal spasticity. Radiographs of the foot including Harris views can demonstrate the abnormal osseous connections that occur between the calcaneus and the talus or navicular. Other measurements on standing lateral foot view can be helpful in assessing the arch issues and the degree of abnormality. Meary's angle is the angle made from the long axis bisectors of the talus and first metatarsal [5]:

●Normal: 0 degrees (<4 degrees up [cavus] or down [planus])

●Mildly abnormal: 4 to 15 degrees

●Moderately abnormal: 16 to 30 degrees

●Severe: >30 degrees

Longitudinal arch angle is normally 150 to 170 degrees (<150 planus, >170 cavus) and is measured from the calcaneal inclination axis (line from the inferior calcaneal tuberosity to the inferior prominence of the distal calcaneus) and the inferior edge of the fifth metatarsal.

Computed tomography (CT) scan is the gold standard to determine whether tarsal coalition is present in patients with rigid pes planus (see 'Tarsal coalition' below). All patients with rigid pes planus warrant referral to a pediatric orthopedic surgeon [6].

Flexible pes planus (flat feet) — Flexible pes planus may be physiologic or pathologic depending upon other associated conditions such as ligamentous laxity, motor weakness in the muscles of the foot, bony abnormalities, or a generalized syndrome [7].

Flexible pes planus has three types:

●Type I – Functional flat foot (calcaneovalgus)

●Type II – Hypermobile flat foot with associated ligamentous laxity and "tight heel cords"

●Type III – Clinical pes planus associated with tibialis posterior tendon dysfunction

Type I — Functional flat foot is the most common type of flat foot in children. It is physiologic and is simply a depression of the longitudinal arch that is associated with varying amounts of heel eversion (ie, calcaneovalgus heel) [7].

Functional flat foot is not usually painful. Low arches in these individuals are considered to be a sign of a strong, stable foot rather than of weakness in the muscles that move the foot. Radiographs are not necessary [4,7].

The best treatment is an adequately supported heel counter (the firm part of the shoe that surrounds the heel) and a well-constructed, cushioned shoe. Rigid orthotics usually are contraindicated because imposing an arch may cause pain and additional symptoms and there is no evidence that they alter or improve musculoskeletal outcomes as the child grows [7,8]. Working with a physical therapist to improve core strength and hip abductors can decrease external rotation of the hip during walking and running may help to decrease the amount of functional pronation.

Type II — In patients who have hypermobile flat foot with associated ligamentous laxity and "tight heel cords," the ligamentous laxity may be familial or part of a generalized syndrome such as Ehlers-Danlos, Marfan, Down, or osteogenesis imperfecta. The condition can be aggravated by contracture of the triceps surae (gastrocnemius-soleus complex) and peroneal muscles (figure 5) [9].

Routine radiography of type II flexible flat feet is not indicated. Radiographs are obtained if the feet are painful and have restricted motion or if the deformity is so severe that orthosis or surgery is being considered [10,11]. Painful causes of flexible flat feet include tarsal coalition, vertical talus, or an accessory navicular bone. (See 'Tarsal coalition' below.)

Treatment is directed at the tight Achilles tendon [12]. Passive stretching exercises may be effective for mild cases. Moderate and severe contractures may require treatment with serial stretching and cast application. Semirigid or even rigid orthoses may be also be incorporated [7]. Surgery is reserved for patients not responding to conservative treatment. Patients with collagen vascular or neuromuscular conditions contributing to painful flat feet warrant early referral to a pediatric orthopedic surgeon.

Type III — Clinical pes planus associated with tibialis posterior tendon dysfunction can often be confused with type II flexible pes planus but it is a distinct clinical entity. Type III flexible pes planus is uncommon in patients who are younger than 20 years. It may be seen in dancers, ice skaters, and athletes who participate in running sports that require rapid changes in direction (eg, basketball, tennis, soccer, ice hockey) because this change places increased stress across the tibialis posterior tendon. (See "Non-Achilles ankle tendinopathy", section on 'Clinical presentation and physical examination'.)

Patients with posterior tibialis tendinopathy typically complain of pain around the posteromedial ankle. Swelling may be present along the course of the tendon, particularly several centimeters proximal to its insertion on the navicular. However, as the condition progresses, partial tearing of the tendon or avulsion from its insertion on the navicular can occur, and the longitudinal arch may drop resulting in a "flat foot" (pes planus). This collapse causes midfoot rotation and impingement of lateral structures. The patient may then complain of lateral ankle pain and a gradual "turning out" of the foot. The diagnosis of posterior tibialis or flexor hallucis longus (FHL) tendinopathy can usually be made on the basis of the history and examination without advanced imaging. (See "Non-Achilles ankle tendinopathy", section on 'Clinical presentation and physical examination'.)

The approach to imaging and treatment are discussed separately. (See "Non-Achilles ankle tendinopathy", section on 'Imaging studies' and "Non-Achilles ankle tendinopathy", section on 'Posterior tibialis tendinopathy'.)

Pes cavus (high arch) — Pes cavus, or high-arched foot, is a condition in which the longitudinal arch is abnormally elevated due to a fixed equinus deformity of the forefoot on the hindfoot [13]. Equinus, which means "horse-like," describes the deformity of plantarflexion at the ankle or within the foot. Equinus deformity often is part of a cavus foot. The cavus foot usually is stable, often has a limited range of motion, and frequently absorbs shock poorly.

Causes of pes cavus include neuromuscular disease, talipes equinovarus (residual clubfoot, either treated or untreated), and traumatic and idiopathic events [14]. The clinician should always investigate for neuromuscular disease in patients with pes cavus. This problem is usually best managed by an orthopedic specialist because of the progressive nature of the deformity.

●Clinical features — There are two forms of the cavus foot deformity. One has an inverted calcaneus with a tight heel cord (the cavovarus foot) [13]. The second has a high arch with a normal heel alignment, usually from weak calf muscles and increased dorsiflexion of the heel with increased plantarflexion of the forefoot. This form is called calcaneocavus.

The symptoms of the cavus foot can be static or progressive [13,14]. The course is typically static in idiopathic cavus foot and progressive if the deformity is caused by a neurologic disease. Patients with idiopathic cavus foot prefer to wear shoes or boots with elevated heels to relieve the stress on the tight heel cords and the plantar fascia.

On examination, the deformity is present with and without weightbearing. The toes may be clawed. Asymmetry of the muscle bulk of the calves should be evaluated with the patient standing [13]. Gait should be evaluated for the presence of foot drop. The heel cords should be tested for tightness by determining the extent of dorsiflexion of the foot. Patients with tight heel cords are unable to dorsiflex the foot beyond the neutral position. The lower spine should be evaluated for neurocutaneous markings (suggestive of spinal dysraphism). Muscle strength and sensation of the foot should be tested.

For the purpose of evaluation and treatment of the young athlete with a cavus foot, categorizing the deformity according to function (eg, flexible, semiflexible, and rigid) is helpful.

These categories can be defined by determining the mobility of the hindfoot on the forefoot using the Coleman standing lateral block test and the Carroll test (figure 6) [9].

•In the Coleman standing lateral block test, the patient stands on a 1- to 1.5-inch thick wooden block, bearing weight on the heel with the lateral border of the foot on the block [9]. The first through third metatarsals hang freely off the medial border of the block into plantarflexion and pronation. The examiner observes the position of the hindfoot. If the foot drops (calcaneovalgus), the subtalar joint is flexible; if the foot goes to neutral, the subtalar joint is semiflexible and forefoot problems may be present (eg, rigid plantarflexed first ray); if the foot remains in varus, the subtalar joint is rigid.

•The Carroll test uses a similar technique to assess the cavus foot [9]. The patient stands on a block, bearing his or her weight on the heel; the forefoot is off the block. If the patient has poor midfoot mobility causing pes cavus with normal subtalar mobility, the rearfoot will fall into neutral because the midfoot no longer blocks that normal movement. If the patient has poor subtalar mobility, they will continue in the rearfoot varus.

●Imaging — The radiologic evaluation of patients with pes cavus should include weightbearing radiographs of the foot and ankle [13,14]. Radiographs of the spine should also be obtained to evaluate for spinal dysraphism. If present, magnetic resonance imaging of the spine is warranted. (See "Closed spinal dysraphism: Clinical manifestations, diagnosis, and management", section on 'Evaluation and diagnosis'.)

●Additional testing — Electromyography, muscle biopsy, and nerve conduction studies may be necessary to determine the specific neurologic problem (eg, myopathy versus neuropathy). (See "Approach to the metabolic myopathies" and "Congenital myopathies" and "Overview of acquired peripheral neuropathies in children" and "Charcot-Marie-Tooth disease: Genetics, clinical features, and diagnosis" and "Overview of hereditary neuropathies".)

●Treatment — The treatment of pes cavus depends upon the etiology. Pes cavus that is caused by neuromuscular abnormalities usually is best managed by orthopedic and neurologic specialists because of the progressive nature of the deformity [13]. Management may include bracing, ankle foot orthotics, or surgery in addition to treatment of the underlying neurologic problem. (See "Myelomeningocele (spina bifida): Orthopedic issues", section on 'Cavovarus' and "Charcot-Marie-Tooth disease: Genetics, clinical features, and diagnosis", section on 'Management'.)

Idiopathic pes cavus may be managed by referral for custom foot orthotics to support the arch, provide shock absorption, and keep the foot and first ray (the first metatarsal and the two phalanges of the great toe) in neutral [15]. Stretching of the plantar fascia and the heel cords may also be beneficial.

BONE CONDITIONS — Bony abnormalities that may occur in children and adolescents include Köhler disease (navicular osteochondrosis, primarily seen in children younger than 10 years of age), Freiberg disease or Freiberg infraction (metatarsal avascular necrosis), Iselin disease (fifth metatarsal traction apophysitis), bunions, bunionettes, and sesamoiditis (sesamoid stress fracture). Tarsal coalition, a fibrous bony connection between two or more of the tarsal bones (image 1 and figure 1), is a condition that is present at birth but becomes symptomatic only during the second decade as the coalition(s) ossify. Patients with tarsal coalition often present with rigid flat feet. (See 'Rigid pes planus (flat feet)' above.)

Köhler disease (navicular osteochondrosis) — Köhler disease refers to idiopathic avascular necrosis of the navicular bone (figure 1), which is most common in children younger than 10 years of age [16]. Patients typically present with progressive midfoot pain that is worse with weight bearing although acute history of midfoot pain after trauma is sometimes obtained. Physical examination is notable for tenderness and swelling over the proximal midfoot [17]. Affected patients typically walk on the lateral portion of the foot.

The clinical diagnosis of Köhler disease is supported by plain radiographs that show flattening, sclerosis, and fragmentation of the navicular bone (image 2) which may be best appreciated by comparison with the unaffected side [16,17]. However, these abnormalities of the navicular are bilateral in approximately 25 percent of patients and may be seen in asymptomatic children as well.

These patients warrant referral to a sports medicine specialist or orthopedic surgeon with pediatric expertise. Initial management usually involves immobilization in a short-leg walking cast for four to six weeks [17]. After that, most patients achieve a normal gait although mild pain may persist for several months. Almost all patients ultimately become asymptomatic. Patients with continued symptoms associated with abnormal healing of the navicular bone warrant referral to a pediatric orthopedic surgeon.

Freiberg disease (metatarsal avascular necrosis) — Freiberg disease or Freiberg infraction describes ischemic injury to the epiphysis of the head of the second, third, or fourth metatarsal at the metatarsophalangeal joint (figure 1) [16,17]. It is most common in adolescent females and may be associated with repetitive trauma or anatomic variants (eg, short or hypermobile first metatarsal) [16].

The clinical presentation of Freiberg disease consists of a gradual onset of dull, aching plantar pain in the region of the affected metatarsal head which is sometimes described as a sensation of walking on a pebble [16]. Pain may be exacerbated by walking barefoot. Physical examination demonstrates pain over the affected metatarsal head which may be associated with swelling or elevation of the corresponding toe and crepitus on passive range of motion of the metatarsophalangeal joint. The diagnosis is made by plain radiographs that show widening at the metatarsophalangeal joint, flattening of the metatarsal head, central joint depression, or subchondral sclerosis (image 3) [16].

Patients with early changes of Freiberg disease will usually respond well to rest, a limited course of nonsteroidal antiinflammatory drugs (eg, ibuprofen), and a metatarsal orthotic designed to reduce the pressure on the metatarsals during weightbearing [16,17]. Patients with advanced disease or continued pain despite nonoperative management warrant referral to an orthopedic surgeon.

Iselin disease (fifth metatarsal traction apophysitis) — Iselin disease typically arises during a period of rapid growth in skeletally immature adolescents and reflects avulsion of the apophysis at the base of the fifth metatarsal [16,17]. It may develop in an active patient during activities that produce ankle inversion and stress such as running, jumping, or cutting (soccer, basketball, gymnastics, or dance). On physical examination, the patient has pain over the base of the fifth metatarsal. The metatarsal may also appear enlarged compared with the other side. Pain is also produced by resisted plantar flexion and eversion.

Plain radiographs are indicated to differentiate Iselin disease from acute fractures (eg, avulsion or stress fractures of the fifth metatarsal) or an os vesalianum (variant sesamoid that is next to the peroneus brevis tendon insertion) [16-18]. Comparative views may show an increase in size of the apophysis with abnormal ossification or slight separation from the metatarsal in patients with Iselin disease (image 4).

Initial management consists of decreasing activities, pain control with cold application a short course of nonsteroidal antiinflammatory drugs (eg, ibuprofen), and stretching and strengthening of the peroneal muscles [17]. Patients with persistent pain may benefit from immobilization with a short-leg walking cast or walking boot. The typical course is for Iselin disease to become markedly better in a few weeks. However, it continues to cause milder symptoms until ossification is complete [19].

Bunion — Valgus malformation of the great toe, commonly known as a bunion, is a common and potentially painful and debilitating condition of unclear etiology (figure 7 and figure 8 and image 5). Bunions are the most common problem affecting the forefoot. They can occur in children and young adolescents but increase in frequency with age. Clinical diagnosis of bunions is primarily based upon a history of great toe pain and increasing valgus deformity. Visual examination of the foot confirms the diagnosis (picture 3 and picture 4). Patients with bunions have altered foot pressure patterns that can lead to the development of other abnormalities, including a depressed foot arch and greater foot pronation. Radiology studies offer limited value to the primary care clinician but may be useful for surgeons to determine the best approach to surgical correction. Bunions are discussed in greater detail separately. (See "Hallux valgus deformity (bunion) in adults".)

Bunionette — Bunionettes are painful bony prominences that occur over the lateral aspect of the fifth (little toe) metatarsophalangeal (MTP) joint (picture 5). In most cases, there is a prominence of the metatarsal head and a varus angle or subluxation of the fifth MTP joint. A widened fourth to fifth intermetatarsal angle suggests either genetic or structural alteration. Injury to the fourth to fifth intermetatarsal ligament from altered gait involving either excessive compensatory supination during toe-off or a supinated foot strike may cause increased separation between the fourth and fifth rays and result in breakdown of the MTP joint capsule (picture 6). (See "Evaluation, diagnosis, and select management of common causes of forefoot pain in adults", section on 'Bunionette (tailor's bunion)'.)

Most bunionettes are readily detected by visual inspection of the foot and rarely cause significant symptoms. When symptoms do occur they typically include pain directly over the fifth MTP joint or over the lateral aspect of the fifth MTP with pressure from the shoe. Examination may reveal abnormal callusing (picture 7) and sometimes mild MTP joint swelling. Wearing shoes with a wider toe box will usually improve painful symptoms. Radiographs have no routine role except in those patients considering surgery.  

Sesamoiditis (sesamoid stress fracture) — The two largest sesamoids in the foot reside inferior to the first metatarsophalangeal (MTP) joint (figure 1) and are susceptible to fracture. Sesamoid injuries occur most commonly in long-distance running and in sports that require rapid acceleration/deceleration and rotating on toes, such as tennis, racquetball, football, soccer, volleyball, and dance. Patients with a sesamoid stress fracture usually complain of poorly localized pain around the first MTP joint for several weeks. Swelling is not generally seen until the injury has progressed. Erythema is typically absent. Often, the patient is unable to localize the pain until the examiner directly palpates the injured sesamoid, most commonly the medial (tibial) sesamoid. Passive dorsiflexion of the first MTP joint can elicit pain in sesamoid fractures. If this movement does not produce pain and a fracture is suspected, some suggest holding the MTP in maximal dorsiflexion and deeply palpating the suspected area, while the patient tries to plantar flex the great toe. (See "Sesamoid fractures of the foot".)

Standard anteroposterior (AP), oblique, and lateral views of the foot are generally sufficient to demonstrate sesamoid fractures (image 6A-B). Special sesamoid views or magnetic resonance imaging may be obtained if initial plain radiographs are normal but suspicion for injury remains high. (See "Sesamoid fractures of the foot", section on 'Diagnostic imaging'.)

Bipartite sesamoids, a normal variant, may be confused with fractured sesamoids. Fracture lines of sesamoids usually have irregular edges (image 6A-B), in contrast to the smooth borders of a partite sesamoid (image 7). In addition, partite sesamoids usually demonstrate even cortication around their entire circumference (image 8), whereas the fracture line of a sesamoid will lack cortication (image 6A-B). (See "Sesamoid fractures of the foot", section on 'Partite sesamoids'.)

The management of sesamoid fractures of the foot is discussed separately. (See "Sesamoid fractures of the foot", section on 'Initial treatment'.)

Tarsal coalition — Tarsal coalition is an abnormal connection (fibrous, cartilaginous, or osseous) between two or more bones in the mid/rear foot (figure 1). The overall incidence in the population is approximately 1 percent [20-22] and has an equal sex distribution. Most coalitions are congenital from a presumed lack of differentiation of mesenchymal tissue in the affected area. Ninety percent of coalitions are calcaneonavicular or talocalcaneal and will present between ages 8 to 12 years and 12 to 15 years, respectively (typically the time of ossification of the coalition) [20]. While many are asymptomatic, the lack of mid/rear foot motion often manifests with generalized mid or rear foot pain that is worsened with activity, especially on uneven ground. Patients may also present with recurrent ankle sprains. Physical examination findings include rigid flat foot, hindfoot valgus, loss of subtalar motion, and limited painful passive ankle inversion.

The diagnosis of tarsal coalition requires appropriate imaging. Foot radiographs are the first line imaging of choice:

●Calcaneonavicular coalitions are best seen on 45 degrees oblique foot radiographs (bridging between the lateral border of the navicular in the anterior facet of the calcaneus). On the lateral radiograph, the "anteater nose" sign shows the elongation of the anterior process of the calcaneus [23].

●Talocalcaneal coalitions are more difficult to appreciate and require special Harris views of the subtalar joint in which the patient stands on the cassette and the x-ray beam is angled between 35 and 45 degrees. The lateral radiograph may show beaking of the head of the talus and the "C" sign, a C-shaped line on lateral radiographs created by the medial dome of the talus and the inferior portion of the sustentaculum tali [24-26].

Both coalitions may demonstrate short neck of the talus or beaking on the dorsal talus [27].

In patients with symptomatic tarsal coalition further imaging should be directed by a pediatric radiologist, orthopedist, or sports medicine specialist. Computed tomography of the foot is the gold standard for diagnosis of osseous coalitions while magnetic resonance imaging may be more useful for further defining non-osseous coalitions [28].

Treatment of asymptomatic coalitions is not indicated because there are no definitive studies demonstrating better outcomes than the natural history of this condition. Patients with symptomatic tarsal coalitions warrant referral to a pediatric sports medicine specialist or orthopedist. Mainstays of nonoperative management include relative rest, a short course of nonsteroidal antiinflammatory medications, and immobilization in a walking boot/short leg cast in hind foot neutral position for four to six weeks. However, up to 30 percent of patients may remain symptomatic despite initial nonoperative therapy and require referral to an orthopedic surgeon with expertise managing tarsal coalitions for further care which may ultimately require surgical correction [29].

INFECTIOUS AND NEUROLOGIC CONDITIONS — Cutaneous infections (cellulitis or abscess) involving the sole of the foot frequently follow disruption of the skin (eg, blister, puncture wound, or insect bite) or may arise from a retained foreign body such as a splinter, rock, or piece of glass. Extension of infection may cause an osteomyelitis. Plantar warts commonly occur on pressure points in the ball of the foot and the heel. Tarsal tunnel syndrome and Morton neuroma are neuropathies caused by compression or inflammation of the tibial nerve or interdigital nerve, respectively.

Cellulitis and abscess — Cutaneous or deeper infections involving the sole of the foot frequently follow disruption of the skin (eg, blister, puncture wound, or insect bite) or may arise from a retained foreign body such as a splinter, rock, or piece of glass. Cellulitis involves infection of the epidermis, dermis, and subcutaneous fat and presents with redness, swelling, tenderness, and induration. Abscesses with pus collecting in the dermis and deeper layers may accompany cellulitis, especially when the infection is caused by methicillin-resistant Staphylococcus aureus or when there is a retained foreign body. (See "Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis", section on 'Skin abscess' and "Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis", section on 'Cellulitis and erysipelas'.)

The diagnosis of a cellulitis or abscess is clinical. Further evaluation should include a radiograph to evaluate for an associated osteomyelitis, radiopaque foreign body, or gas gangrene. If a radiolucent foreign body is suspected, ultrasound may be useful. Ultrasound may help differentiate between cellulitis and abscess in some patients and guide drainage procedures. Cultures of blood or pus are typically not helpful in patients with mild infections but may be warranted in patients with systemic toxicity, extensive skin involvement, underlying comorbidities (lymphedema, malignancy, neutropenia, immunodeficiency, splenectomy, diabetes), special exposures (animal bite, water-associated injury), or recurrent or persistent cellulitis. Cultures of swabs from intact skin are not helpful and should not be performed. (See "Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis", section on 'Cellulitis and erysipelas' and "Techniques for skin abscess drainage", section on 'Bedside ultrasonography'.)

The treatment of cellulitis and abscess is discussed separately. (See "Techniques for skin abscess drainage" and "Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis".)

Osteomyelitis — Osteomyelitis in the foot may arise in association with a retained foreign body or puncture wound (eg, nail driven through a sneaker). Although the clinical presentation of osteomyelitis can be nonspecific, signs of infection (ie, fever, localized erythema, induration, swelling, and warmth and/or elevated erythrocyte sedimentation rate and C-reactive protein levels) may be present. (See "Hematogenous osteomyelitis in children: Clinical features and complications".)

The diagnosis of osteomyelitis is supported by a combination of (see "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Diagnostic approach'):

●Clinical features suggestive of bone infection (constitutional symptoms, focal symptoms and signs of bone inflammation, limitation of function, elevated erythrocyte sedimentation rate, and/or C-reactive protein) (see "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Clinical suspicion' and "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Blood tests')

●An imaging study with abnormalities characteristic of osteomyelitis (table 1) (see "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Radiographs' and "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Advanced imaging')

●A positive microbiologic or histopathologic specimen (see "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Microbiology' and "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Histopathology')

●A response to empiric antimicrobial therapy (see "Hematogenous osteomyelitis in children: Evaluation and diagnosis", section on 'Response to empiric therapy')

Consultation with a pediatric orthopedic surgeon and radiologist is warranted when osteomyelitis is suspected to guide the diagnostic approach and treatment. The evaluation and treatment of osteomyelitis is discussed in detail separately. (See "Hematogenous osteomyelitis in children: Evaluation and diagnosis" and "Hematogenous osteomyelitis in children: Management".)

Plantar warts — Plantar warts commonly occur on pressure points in the ball of the foot and the heel. Overlying callus may cause pain. On inspection, plantar warts appear as hyperkeratotic papules that interrupt normal skin lines. They may also have tiny red or black dots within the lesion that represent thrombosed capillaries (picture 8). The management of plantar warts is discussed separately. (See "Cutaneous warts (common, plantar, and flat warts)", section on 'Common warts and plantar warts'.)

Tarsal tunnel syndrome — The tarsal tunnel is a bony canal that runs below the medial malleolus and through which travel the posterior tibialis, flexor hallucis and flexor digitorum tendons, posterior tibial artery and vein, and tibial nerve (figure 9). Tarsal tunnel syndrome is caused by increased pressure in the canal resulting in tibial nerve pain that typically radiates to the plantar surface of the forefoot. Pressure can come from scar tissue from prior foot injury to the medial ankle or a markedly pronated gait that causes the roof of the tunnel to collapse. Runners with inadequate hip stability may repetitively strike the contralateral tarsal tunnel with the medial heel in the swing phase of gait resulting in tibial nerve pain patterns. Over time, compression of the tarsal tunnel can also result in injury of the posterior tibialis or flexor hallucis tendons. (See "Overview of lower extremity peripheral nerve syndromes", section on 'Tarsal tunnel syndrome'.)

Patients with tarsal tunnel syndrome typically present with aching, burning, numbness, and tingling involving the sole of the foot, the distal foot, the toes, and occasionally, the heel. The pain may radiate up to the calf or higher. The discomfort is often most irritating at night, may be worse after standing, and sometimes leads to the desire to remove the shoes. The physical examination may be normal in patients with tarsal tunnel syndrome of relatively recent onset. When present, key findings include swelling below and posterior to the medial malleolus. Examination may demonstrate a prominent Tinel's sign (paresthesia when tapping over the nerve posterior to the medial malleolus) with sensory loss over the plantar surface of the foot, not extending onto the dorsal foot. Diagnosis may require nerve conduction studies in patients with equivocal clinical findings. (See "Overview of lower extremity peripheral nerve syndromes", section on 'Tarsal tunnel syndrome'.)

The treatment of tarsal tunnel syndrome is discussed separately. (See "Overview of lower extremity peripheral nerve syndromes", section on 'Tarsal tunnel syndrome'.)

Morton neuroma — Although uncommon in children and adolescents, interdigital neuromas (often referred to as Morton neuroma) are thought to be due to swelling and scar tissue formation on the small interdigital nerves. They most commonly involve the third interdigital space but may also develop in the second and fourth. An intermetatarsal bursitis can cause a similar pain.

The runner with a neuroma may complain of numbness of the involved toes or pain that increases with activity and is usually felt on the plantar surface between the third and fourth toes (figure 10). Examination may reveal a clicking sensation (Mulder sign) when palpating this interspace while simultaneously squeezing the metatarsal joints. Overpronation and tight shoes are often associated with the condition.

Ultrasound offers an inexpensive option for identifying Morton neuroma with accuracy comparable to magnetic resonance imaging (MRI), and can help to distinguish a neuroma from intra-metatarsal bursal swelling or synovitis in adjacent joints.

Morton neuroma is discussed in greater detail separately. (See "Evaluation, diagnosis, and select management of common causes of forefoot pain in adults", section on 'Interdigital (Morton) neuroma'.)

SUMMARY

●Evaluation – Foot pain in the young athlete can originate in the bones (fractures), ligaments (sprains), muscles and tendons, or fascia. Careful localization of the pain can help to narrow the differential diagnosis (figure 2 and figure 1). (See 'Evaluation' above.)

●Acute injuries – Common acute injuries of the mid- and forefoot in children and adolescents consist of friction blisters, wounds to the sole of the foot, stubbed toes with subungual hematoma or phalangeal fractures, and metatarsal fractures. Forced hyperextension of the first toe may cause a metatarsophalangeal joint sprain. Lisfranc complex injuries are less commonly seen but warrant prompt referral to an orthopedic surgeon with pediatric expertise. (See 'Acute injuries' above.)

●Overuse injuries – Overuse injuries of the mid- and forefoot include flexor hallucis longus tendinitis and tibialis posterior tendinitis. Less commonly, children and adolescents can develop plantar fasciitis and flexor digitorum longus tendinitis. (See 'Overuse injuries' above.)

●Arch abnormalities – Among arch abnormalities, flexible pes planus (flat feet) is most common and typically describes functional flat feet that are physiologic and asymptomatic. Patients with painful flexible pes planus warrant evaluation for associated ligamentous laxity, tight heel cords, and tibialis posterior tendon dysfunction. Rigid pes planus (flat feet) and pes cavus (fixed high arch) warrant specialty referral to evaluate underlying abnormalities such as tarsal coalition (pes planus), neuromuscular disease (pes cavus), or talipes equinovarus (residual club foot causing pes cavus). (See 'Arch abnormalities' above.)

●Bone conditions – Bony abnormalities that may occur in children and adolescents include Köhler disease (navicular osteochondrosis, primarily seen in children younger than 10 years of age) (image 2), Freiberg disease or Freiberg infraction (metatarsal avascular necrosis), Iselin disease (fifth metatarsal traction apophysitis) (image 3), bunions, bunionettes, and sesamoiditis (sesamoid stress fracture). Tarsal coalition, a fibrous bony connection between two or more of the tarsal bones (image 1 and figure 1), is a condition that is present at birth but becomes symptomatic only during the second decade as the coalition(s) ossify. Patients with tarsal coalition often present with rigid flat feet. (See 'Bone conditions' above.)

●Infectious and neurologic conditions – Cutaneous or deeper infections (cellulitis or abscess) involving the sole of the foot frequently follow disruption of the skin (eg, blister, puncture wound, or insect bite) or may arise from a retained foreign body such as a splinter, rock, or piece of glass. Extension of infection may cause an osteomyelitis. Plantar warts commonly occur on pressure points in the ball of the foot and the heel (picture 8). Tarsal tunnel syndrome and Morton neuroma are neuropathies caused by compression or inflammation of the tibial nerve or interdigital nerve, respectively. (See 'Infectious and neurologic conditions' above.)