A Comprehensive Review Of Pediatric Orthoses

By Russell G. Volpe, DPM

Shells made of more rigid materials and/or of increased thickness are the best choices for treating children who have generalized ligamentous laxity. Other modifications such as a deep heel seat, increased calcaneal pitch to lock the oblique midtarsal joint axis and medial and lateral flanges to reduce transverse plane compensations of the midfoot will aid in control of the foot with notable laxity.
Due to the significant medial and lateral instability of children with ligamentous laxity, employing an orthotic device capable of supramalleolar control in the frontal and transverse plane is often necessary to exert adequate control over the closed-chain foot and leg complex. An ideal device with the necessary medial and lateral support is the supramalleolar orthosis (SMO), which extends above the malleoli allowing for control of the tibio-fibular segment. The relatively low height of this device often makes it more cosmetically and functionally appealing than the higher ankle-foot orthosis.
In cases in which you find the SMO is not sufficient to manage superstructural compensations of the ankle and leg, an ankle foot orthosis is the device of choice. One example is the Dynamic Control Orthosis, which consists of a custom functional foot orthosis, a hinged ankle joint and custom molded medial and lateral leg uprights to control superstructural movements. This orthosis also includes a posterior bridge connecting the medial and lateral uprights, which enhancing the proximal control of the leg. This modification is an improvement over other hinged ankle braces that are currently available.
Using thicker shells and more rigid materials are also necessary in managing the pronated foot in the obese child. Longitudinal arch fillers will help reduce the increased compression of the arch area of the shell you’ll typically see in overweight patients. Soft tissue supplementation at the foot/orthosis interface may help reduce the hard feel of such devices and increase shock absorption necessary for sports.

How To Handle Rotational And Angular Disorders
Rotational and angular disorders that produce both in-toeing and out-toeing, bowing and knock-knees may contribute to a compensatory pes valgus. The presence of femoral anteversion, internal tibial torsion, genu varum or valgum will place an abnormal force on the developing foot and will either precipitate abnormal pronation or aggravate any existing abnormal pronation. An internal femoral torsion or position and internal or low tibial torsion will generally lead to an adduction or medial deviation of the talus in the closed kinetic chain. This precipitates the onset of pronation of the subtalar joint or aggravates an already pronated or everted attitude.

Similarly, an external femoral torsion/position or an external tibial torsion also contributes to excessive pronation in the child. A medial displacement of the center of gravity results from the externally positioned leg, facilitating compensation of the subtalar joint.
Genu valgum or varum outside of physiologic ranges is detrimental to the pronated foot. Abnormal frontal plane forces placed on the rearfoot lead to compensatory pronation of the subtalar joint. For example, in the case of genu valgum, the center of gravity passing through the leg is displaced medially over the foot relative to the axis of the subtalar joint. This maintains the foot in the pronated position.
Orthoses for rotational disorders benefit from flanges and extensions such as gait plates. Orthoses for angular disorders benefit from high posting and out-flared or wide posts to stabilize the post plate in the frontal plane.

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