Polio Place

Irwin M. Siegel, MD

Patients with post-polio weakness can often benefit by using an appropriate brace.

Braces can 1) provide support, 2) correct a flexible deformity, or 3) relieve pain. Usually it is best to correct a fixed deformity through stretching or surgery before applying the brace. Post-polio patients require special consideration when it comes to bracing. They usually present with both weakness and deformity. They often have post-polio muscular atrophy (so-called "post-polio syndrome") often accompanied by the arthritic changes of advancing age accelerated by joint deformity secondary to their poliomyelitis. Bracing can sometimes avoid the need for surgery. Patients often have worn braces during earlier rehabilitation and they sometimes present in braces. These are often heavy leather and stainless steel calipers. Though cumbersome, patients get used to their weight as they feel "supported." It is sometimes difficult convincing the patient to accept a modern plastic brace which is thinner and lighter, though equally supportive.

Let us now consider some of the special problems in bracing for the post-polio patient.

Lower extremities:
The legs are more frequently in need of bracing than the arms. Where quadriceps (thigh) weakness is modest, a neoprene wrap-around knee sleeve can offer sufficient support, especially if augmented by the use of a cane. With severe weakness and an almost flail limb, support is provided with a thin plastic knee-ankle-foot orthosis (KAFO) with Velcro closures and an eccentrically-placed knee hinge which permits knee flexion during the swing phase of gait, locking in extension on heel strike. Where indicated, an ischial weight-bearing socket can provide hip support. Sometimes elastic strapping can effectively substitute for weak hip extensors.

Knee position can be adjusted in a short-leg brace (ankle-foot orthosis) by adjusting the position of the ankle on stance. Modest quadriceps weakness can be addressed in this way. For instance, an ankle-foot orthosis (AFO) can incorporate slight equinus (plantar flexion) for toe-touch, forcing the knee into extension on toe weight-bearing. Where hyperextension (back knee) is a problem, lowering the heel of the brace can cause the knee to flex (bend) on heel strike.

For the average post-polio patient with calf and thigh weakness, the most satisfactory below-knee brace is hinged and allows free plantar flexion of 15-20° while permitting only 5-10° of ankle dorsiflexion. This provides adequate stability yet permits enough ankle mobility to facilitate stair walking.

Orthotics (arch supports) and shoe modifications can balance the foot. Heel grip arch inserts or supramalleolar orthoses (SMOs) can help position and support the ankle.

The judicious use of a cane or forearm or axillary crutches can stabilize gait. Every five pounds of force transmitted through such an appliance relieves the hips of 25 pounds of pressure. However, a patient requires strong upper extremities to use crutches or a cane, as the arms now become weight-bearing extremities.

Upper extremities:
A variety of neoprene sleeves, with or without stays, can be used for elbow support. Off-the-shelf wrist splints as well as custom dynamic finger splints are available to assist weakened hands. The neoprene or elastic thumb spica will stabilize the thumb, reduce pain and assist pinch.

Spine:
The torso and spine can be supported by a variety of custom braces. Some are total contact, others use three-point pressure (sternum, pubis, spine) to maintain upright spinal posture.

A weak neck can be supported by a soft myocervical collar. Where a more substantial brace is indicated, a plastic (C-breeze or Aspen type) collar can be prescribed. Lightness, as well as support, is offered by the Oxford cervical brace.

Summary
The special needs of the post-polio patient provide a unique challenge to his physician and orthotist. However, with careful consideration of the faulty biomechanics involved in each case an appropriate brace can be fabricated that will assist the patient to live as functionally as possible for as long as is feasible.

Dr. Siegel is an orthopaedic surgeon at Rush University Medical Center, Chicago, Illinois. He specializes in the orthopaedic and physiatric rehabilitation of patients with neuromuscular disorders including post-polio syndrome.