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فیزیوتراپی تخصصي ستون فقرات - خلاصه ?Flatfoot in Children: How to Approach
خلاصه ?Flatfoot in Children: How to Approach شنبه بیست و چهارم آذر 1386 22:37

Among them, the development of flatfoot is the most common. As the parents observe their

child standing they can’t help but worry about the abnormal appearance, with the arch fallen,

the feet pressed flat to the floor and the heels that seem to rotate out to the sides. They wonder how the child can possibly get around on those things, and worry about the possibility of future difficulties or discomfort.

For the pediatrician evaluating flatfoot, it is important to differentiate between flexible and nonflexible (rigid) flatfoot, and to classify the condition as painful or painless.

 

 

Normal development of foot in children

Despite its small size, the newborn foot is complex, consisting of 26 to 28 bones. The foot can be divided into three anatomic regions (Figure 1): the hindfoot or rearfoot (talus and calcaneus); the midfoot (navicular bone, cuboid bone, and three cuneiform bones); and the forefoot (metatarsals and phalanges)[3].

All children are born with flat feet. Almost every child's foot initially has a large fat pad on the inside arch which slowly decreases as they grow. The longitudinal arch of the foot is not present at birth and slowly develops during childhood, usually by about age five or six. It is a process that occurs throughout growth and is not affected by the presence or absence of external arch support.

 

Flexible flatfoot is considered to be a manifestation of a constitutional laxity affecting all ligaments and joints, and if the foot arch appears abnormal, it is usually the result of weight-bearing stresses.

 

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Pathophysiology

 

 dynamic factors:

Function and structure of the medial longitudinal arch are affected by numerous anatomic structures, all offering potential contributions to the pathophysiology. The posterior tibial muscle and corresponding tendon are crucial to hindfoot position and foot flexibility during the gait cycle. Originating  from the posterior aspect of the tibia, interosseous membrane, and fibula, the

posterior tibial muscle and subsequent tendon passes posteromedially behind the medial malleolus and then inserts via multiple bands into the navicular, cuneiforms, metatarsal bases, and the sustentaculum tali.

Ankle plantarflexion and forefoot adduction-supination with resultant subtalar inversion are key functions of the posterior tibialis tendon because of its posteromedial position. During the gait cycle, the foot must transition from a flexible construct at heel strike to accommodate irregular surfaces to a rigid construct at push off to maintain a rigid lever for ambulation[9].

 

The natural antagonist of the posterior tibial muscle is the peroneus brevis, which is responsible for forefoot abduction and subtalar joint eversion. When PTT insufficiency occurs, several deforming forces are produced. Peroneal musculature overpull may cause forefoot valgus combined with long-term heel valgus, which produces Achilles tendon contracture and transforms the gastrosoleus  muscles into heel everters (rather than inverters).

 

Static factors:

Other structures vital to the medial longitudinal arch are considered static. Individual shape and size of the bony architecture of the medial arch offer significant stability. Recently, the spring ligament complex has received much attention as an important stabilizer of the medial arch[11]. The complex ligamentous support system surrounding the talonaviculocalcaneal joint is comprised of several parts, including the superomedial calcaneonavicular ligament, inferior calcaneonavicular ligament, and a portion of the superficial deltoid. The degree of stability contributed by the spring ligament complex and deltoid ligament remains unclear. The relationship of the central component of  the plantar fascia to medial arch support has long been attributed to the windlass effect.

 

Inherited factors:

The tendency to develop flexible flatfoot is inherited. The etiology of this condition is most likely excess laxity of the joint capsules and ligaments that allow the tarsal arch to collapse when weight is applied. Baby fat and ligamentous laxity at this age predispose to flattening, and rapid growth can make it even more apparent. Several studies have shown that the critical age for the development of the longitudinal arch is before six years.

 

Rigid flatfoot:

Is a congenital deformity that caused by failure of the tarsal bones to separate, leaving a bony, cartilaginous or fibrous bridge between two or more of the tarsal bones. The coalition limits normal subtalar and midfoot motion, leading to inflammation of the involved joints. The peroneal tendon crosses over the subtalar joint and often goes into spasm secondary to subtalar inflammation, hence the term "peroneal spastic" flatfoot. Tarsal coalition is present in approximately 1 percent of the population and is bilateral in 50 to 60 percent of patients[14].

 

Clinical Manifestation

Flexible flatfoot in a child almost never causes any problems. Children with flexible flatfoot, in general, are asymptomatic. If it persists into adolescence, some may experience mild aching along the bottom of the foot. Flexible flatfoot may become symptomatic in adolescents. Symptoms begin to develop as the contracted Achilles tendon limits full ankle dorsiflexion, thus transferring forces to the midfoot. Over time, these forces result in the breakdown of the tarsal joints. Patients complain of vague pain in the medial arch and ankle.

 

 

physical examination:

 On physical examination, the foot has a flat or rocker bottom, and the calcaneus valgus is apparent when standing. When the patient is standing on tiptoe, the calcaneus inverts slightly but not fully. Ankle dorsiflexion is limited to less than 5 degrees secondary to a contracted Achilles tendon. The normal subtalar and transverse tarsal motion is decreased by approximately 50 percent[18].

 

Patients with tarsal coalition have insidious and occasionally acute onset of arch, ankle or midfoot pain. Patients are predisposed to frequent ankle sprains secondary to the limited  subtalar motion. On physical examination, the patient will have a slightly flattened or flat arch. A standing calcaneal valgus is present, which will fail to invert when standing on tiptoe. Little to no motion is present in the subtalar and transverse tarsal joints, and stress on these joints frequently causes pain.

 

Physical examination of the foot

 In neonate, simultaneous observation of both feet can reveal many deformities. The skin should be examined for unusual creases or folds that can be formed by various foot deviations. Certain areas of the skin might be abnormally taut, indicating extra tension on the skin, while the skin on the opposite side of the foot might reveal loose, excessive skin folds. During the next part of the examination, various foot and ankle joints are moved through their respective ranges of motion. The joints should be assessed for flexibility or rigidity, unusual positions, lack of motion, and asymmetry. Finally, the vascular examination consists of assessment of capillary refill and skin color, because pulses are difficult to palpate.

Flexible: While standing they display a dropped medial longitudinal arch, foot eversion and calcaneus valgus. With the child seated and legs dangling, the normal arch contour returns and is accentuated with passive dorsiflexion of the great toe.

 A nonflexible or rigid flatfoot: will remain without a detectable arch in both instances. When the child stands on tiptoe, a flexible flatfoot will demonstrate an arch, with the heel pointing slightly in towards the midline which indicates that calcaneus invert from its valgus position (Fig. 2). Then ask the child to stand on his heels, as ability to do this shows good flexibility of the heel cord or Achilles tendon. Standing on the outer and then inner borders of the foot could demonstrate good mobility of some important joints in the foot. Subtalar and transverse tarsal motion is normal in patients with flexible flatfoot. To determine subtalar motion; the examiner stabilizes the ankle with one hand and grasps the calcaneus with the other. The calcaneus is then passively everted and inverted. The normal total range of motion is between 20 and 60 degrees, with the inversion component twice that of the eversion component. Transverse tarsal motion is determined by grasping the calcaneus with one hand and the forefoot with the other. The forefoot can normally be adducted 30 degrees and abducted 15 degrees.

 

Treatment:

In general, painless flatfoot requires no special treatment. Flexible flatfoot in a child almost never causes any problems and asymptomatic flexible flatfoot requires no treatment, and no evidence indicates that early treatment will prevent the development of symptomatic flexible flatfoot as an adult. In one prospective study[22] 98 children with flexible flatfoot were treated with corrective orthopedic shoes, Helfet heel cup, a custom-molded plastic heel cup, or received no treatment.

All of the groups demonstrated a significant improvement on radiographs, with no difference apparent among the groups after three years

Proper footwear is important for the developing foot; but, whenever safety and comfort allow, going barefoot stimulates proprioceptors and encourages muscular coordination and strength. The  reduced incidence of flatfoot seen in barefoot populations suggests that muscle strength and mobility may be important factors in the normal development of the arches, and that a child is more likely to develop a flexible, yet strong arch when going barefoot [14,25].

There is also evidence that using arch supports or even wearing shoes regularly before age 6 may worsen flat foot by interfering with the normal development of foot muscles. In addition, arch supports and special shoes are uncomfortable for children. So we need to encourage parents to let their children go barefoot whenever it is safe, and to select shoes based on function, not merely on style or cost.

Strengthening of the child's lower leg muscles with home exercises, especially tibialis posterior, and internal/external rotation exercises may have a role. Also, having the child perform the towel-gathering exercise ('scrunching' a towel lying on the floor with the toes) for 15 minutes daily may be helpful.

If the child is 10 or older, the flexible flatfoot can be considered permanent, and long-term use of orthotics will be required to prevent future problems in the feet, lower extremities, and spine. This is especially true for overweight or athletically active youngs who are symptomatic. They may experience mild aching along the bottom of the foot. Depending on the nature of the pain, treatment

might begin with heel cord stretching exercises. If it persists, shoe inserts might be needed. Surgical treatment for persistent pain is rarely needed.

There are a group of patients in whom flexibility of the foot is decreased by age. This group is called as semi-rigid flatfoot. Treatment consists of a longitudinal arch support with a firm heel counter, such as the UCBL (University of California Biomechanics Lab) orthosis. Patients should be fitted for a heel lift, and aggressive heel cord stretching is recommended if an equinus deformity is present[27].

A child with a symptomatic tarsal coalition should be treated initially with a short leg walking cast for four to six weeks to allow the inflamed joints to rest. An ankle-foot orthosis  or posted foot orthosis can then be prescribed to minimize the subtalar and transverse tarsal motion. Patients who fail to respond to conservative treatment or who are involved in competitive athletics should be referred to an orthopedic surgeon[19,28].

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