Variations in Plastic Orthoses for the Developing Child



Plastic lower-limb orthoses offer many advantages to handicapped children, but their high cost and fixed dimensions limit applicability. We modified several plastic orthoses to permit circumferential and longitudinal adjustment of the devices, thus maintaining a more prolonged limb-orthosis congruence in developing children. Three cases are illustrated to introduce the concept of orthotic modification for children. We are continuing our research, focusing on knee and above-knee orthoses.


The development of thermomalleable plastics and their application to the field of lower-limb orthotics have permitted the fabrication of orthoses that provide superiority in cosmesis, comfort, alignment, function, and strength-weight ratios 1-8 . The concept of plastic orthoses relevant to the child offers many advantages, particularly where deformity prevention and correction enhance the results of surgical reconstruction, or in many cases obviate the need for surgery. However, the currently available fabrication techniques that include plaster casting will require modification to allow "growth" of the orthosis to match the normal development of the child.

In a two-year period we prescribed and fabricated 89 plastic lower-limb orthoses for children with musculoskeletal disabilities. In the majority of cases, we utilized the basic plastic designs. In others, we modified the plastic orthoses to maintain continuous congruency between the developing child and the orthosis.

Our article describes the orthotic variations, utilizing three examples.

Case Presentations

Case 1. R.R., a four-year-old boy with severe physiological bilateral genu valgum, initially was provided with bilateral conventional "long-leg braces." Poor cosmesis, excessive weight, discomfort, and variable correction (depending on how tightly the straps were adjusted) led to discarding of the braces, with worsening of the knee deformities. Figure 1 illustrates the patient's new bilateral modified above-knee orthoses, with single metal uprights attached to the shoes by limited-motion ankle joints. The precisely contoured knee sections provided comfort, while the three plastic straps allowed the parent to adjust the orthoses' circumferences as the child grew and gained weight. The highly congruent thigh and leg sections served as points of counterforce to the primary correcting force, and the wide areas of the orthoses permitted a high degree of comfort since considerable force was used to correct the frontal alignment of the limbs. Figure 2 demonstrates the metal upright attachment to the orthosis and shoe. As the child grew, a longer upright was added, thus achieving continuing fit. Figure 3 illustrates the precise application of orthoses to limbs, with a very acceptable correction of the knee deformities. The longevity of the original plastic orthoses was 17 months, with two subsequent replacements over 39 months. The orthoses finally were discontinued, and the correction was maintained without surgical intervention.

Case 2. L.J., a three-year-old girl with diplegic cerebral palsy, was admitted to our service with bilateral equinus, knee instability and deformity, weakness of knee and ankle musculature, and spastic hamstrings producing knee-flexion contractures. A well contoured, modified supracondylar knee-ankle orthosis was applied to the right lower limb, with resultant knee support, correction of knee-flexion contracture, and improvement of gait ( Figure 4 ). A standard "short-leg brace" was applied to the left lower limb, with less than optimal improvement. Figure 5 illustrates a short extensible upright, riveted to the plastic orthosis, that allows "longitudinal growth" of the appliance. A removable liner accommodates transverse growth.

Case 3. B.D., a seven-year-old girl, was evaluated in our Orthotic Clinic and was noted to have a "flail" right leg and a painful left ankle following failure of a reconstructive procedure. A posterior solid-ankle orthosis was fabricated for the left ankle, with telescoping capability of the vertical section. Pelite lining of varying thickness was used to compensate for circumferential growth ( Figure 6 and Figure 7 ). A spiral below-knee orthosis for the right leg was modified by attaching the spiral more posteriorly on the proximal band. As the child grew, the attachment was moved more anteriorly, thus lengthening the spiral to match tibial growth ( Figure 8 and Figure 9 ). The child wore both devices for 17 months before replacement was needed.


A major advantage of plastic orthoses is clearly their cosmetic value to the handicapped. Understandably, the disabled perceive themselves as "less crippled" whenever needed devices are not too evident, particularly for children who must compete with their critical peers.

We believe that children should have access to all available plastic orthoses, recognizing that modifications are necessary to prolong the usefulness of each device. The above cases demonstrate an attempt to attain device longevity.

In the next phase of our continuing investigative project we will apply the concept of orthotic circumferential and longitudinal "growth" to knee and above-knee designs, utilizing Pelite linings and telescoping plastic uprights.

It is our hope that our brief article will encourage other investigators to contribute their expertise to this project.

1. Corcoran, P. J., Evaluation of a plastic short leg brace. A thesis for Degree of Master of Science, University of Washington, May 1968.

2. Demopoulos, J. T., and A. Cassvan, Experience with plastic orthoses in children: preliminary observations. Bull. Hosp. Joint Dis., 32:148-167, October 1971.

3. Demopoulos, J. T., A. Cassvan, and J. M. Swonden, Experience with plastic lower extremity orthoses. Bull. Hosp. Joint Dis., 33:22-46, April 1972.

4. Demopoulos, J. T., and J. E. Eschen, Modification of plastic orthoses for children. Bull. Hosp. Joint Dis., 34:156-160, October 1973.

5. Jebsen, R. H., B. C. Simons, and P. J. Corcoran, Experimental plastic short leg braces. Arch. Phys. Med. Rehabil., 49:2:108-109, February 1968.

6. Kay, H. W., Clinical applications of the Veterans Administration Prosthetics Center patellar-tendon-bearing brace. Artif. Limbs, 15:1:46-67, Spring 1971.

7. Lehneis, H. R., New concepts in lower extremity orthotics. Med. Clin. N. Am., 53:3:585-592, May 1969.

8. Sarno, J. E., and H. R. Lehneis, Prescription considerations for plastic below-knee orthoses. Arch. Phys. Med. Rehabil., 52:11:503-510, November 1967.