Bracing

Braces are devices which hold the extremities in a stable position. The goals of bracing are to increase function, prevent deformity, keep the joint in the functional position, stabilize the trunk and extremities, facilitate selective motor control, decrease spasticity and protect the extremity from injury in the postoperative phase. Their design and use requires an understanding of human biomechanics. Indications differ according to the age, selective motor control level, type of deformity and functional prognosis of the child. The physician writes the prescription and the orthotist manufactures the brace. A close communication is necessary between them. Braces are custom-made from a plaster model of the child’s extremity and fabricated with plastic materials. Evaluate the child for the first time together if possible. When the brace is ready, teach the child and the family how to put it on, take it off and how to look after it together with the therapist and the orthotist. Consider any modifications for better fit during this period. Evaluate the child once again after he begins to use the brace. The brace should be simple, light but strong. It should be easy to use. Most importantly it should provide and increase functional independence. The child will easily accept and use a brace which carries the above characteristics. Children will resist braces if the brace interferes with function. Do not insist if the child does not want to use the brace. The child quickly outgrows the brace in the growth spurt period. Indications change as the child’s functional status changes. Evaluate the child at 3-6 month intervals and renew all braces regularly as the child grows.

Lower extremity bracing
Orthotics are usually named according to the body parts they cover.

Braces in CP

Ankle foot orthoses: AFOs
Knee-ankle foot orthoses: Plastic KAFOs and knee immobilizers
Hip abduction orthoses
Thoracolumbosacral orthoses: TLSOs
Supramalleolar orthoses: SMOs
Foot orthoses: FOs
Hand splints

Various kinds of ankle foot orthoses called AFOs are the most common braces used in CP. Static braces immobilize the joint while flexible or hinged ones use bodyweight to stretch the muscles of the leg and ankle. AFOs provide appropriate contact with the ground during stance and foot clearance during swing. Knee immobilizing splints and hip abduction splints are prescribed both for nonambulatory and ambulatory children. Compliance with night splints to prevent deformity is low. KAFOs work in children who use them. AFOs are not very useful as night splints because they do not prevent knee flexion.

Ankle foot orthoses (AFO)

The AFO is the basic orthosis in CP and is a crucial piece of equipment for many children with spastic diplegia. The main function of the AFO is to maintain the foot in a plantigrade position. This provides a stable base of support that facilitates function and also reduces tone in the stance phase of gait. The AFO supports the foot and prevents drop foot during swing phase. When worn at night, a rigid AFO may prevent contracture. AFOs provide a more energy efficient gait but do not prevent foot deformities such as pes valgus, equinus or varus. It is better to use the AFOs part time in most children. They may cause sensory deprivation and muscle atrophy if used continuously. Adolescents generally outgrow their braces and adults do not comply with them.

There are various types of the AFO.

Types of AFO

• Solid AFO
• Posterior leafspring AFO (PLSO)
• Ground Reaction AFO (GRAFO)
• Antirecurvatum AFO
• Hinged AFO
• Hinged GRAFO
• Hinged antirecurvatum AFO

Solid AFO: The solid or rigid AFO [B, C] allows no ankle motion, covers the back of the leg completely and extends from just below the fibular head to metatarsal heads. Raise the sides for better varus-valgus control. The solid AFO enables heel strike in the stance phase and toe clearance in the swing phase. It can improve knee stability in ambulatory children. It also provides control of varus/valgus deformity. Advise solid AFOs to prevent contractures and to provide ankle stability in the standing frame in nonambulatory children. Because they are more comfortable compared to a short leg cast, consider using them in the early postoperative period for protection of the operated extremity.

Posterior leaf spring AFO: A PLSO is a rigid AFO trimmed aggressively posterolaterally and posteromedially at the supramalleolar area [D]. This provides flexibility at the ankle [E] and allows passive ankle dorsiflexion during the stance phase. A PLSO provides smoother knee-ankle motion during walking while preventing excessive ankle dorsiflexion, particularly in larger children who have the strength to deform the material. However it also increases knee flexion in stance. Varus-valgus control is also poor because it is repeatedly deformed during weight bearing. The brace breaks when it is repeatedly deformed. These AFOs are frequently renewed because of material failure. A PLSO is an ideal choice in mild spastic equinus. Do not use in patients who have crouch gait and pes valgus.

GRAFO or FRO (Ground reaction or floor reaction AFO): This AFO is made with a solid ankle at neutral [F]. The upper portion wraps around the anterior part of the tibia proximally with a solid front over the tibia. The posterior opening extends to the malleoli level. The rigid front starts just below the tuberositas tibia with a band at the back to create a three point pressure distribution and provide strong ground reaction support for patients with weak triceps surae [G]. The foot plate extends to the toes. The ankle may be set in slight plantar flexion of 2-3o if more corrective force at the knee is necessary. Use the GRAFO in patients with quadriceps weakness or crouch gait. It is an excellent brace for patients with weak triceps surae following hamstring lengthening. Use an anterior strap in children below 15 kg. Above that, use a rigid GRAFO if the foot alignment is poor and a hinged GRAFO if it is satisfactory. The benefit depends also on the work quality of the orthotist. Children with static or dynamic knee flexion contractures do not tolerate the GRAFO. Surgically release the knee flexion contracture before prescribing the GRAFO.

GRAFO as seen from posterior, lateral and anterior. The characteristic
of a GRAFO is the tibia restraint in front. This restraint prevents the tibia from moving forward as the person starts to put his weight on his extremity in stance (the second rocker phase of stance) It prevents excessive ankle dorsiflexion and crouch gait.

Anti-recurvatum AFO: This special AFO is molded in slight dorsiflexion or has the heel built up slightly to push the tibia forward to prevent hyperextension during stance phase. Consider prescribing this AFO for the treatment of genu recurvatum in hemiplegic or diplegic children. Anti-recurvatum AFOs may be solid or hinged depending on the child’s tolerance.

The mechanism of antirecurvatum AFOs: The AFO is built in 5o dorsiflexion. Therefore initial contact occurs with the ankle in dorsiflexion. Equinus is prevented. The back of the AFO pushes the tibia forward and the ground reaction force vector slides behind the knee joint creating a flexion moment at the knee.

Hinged AFO
Hinged AFOs have a mechanical ankle joint preventing plantar flexion, but allowing relatively full dorsiflexion during the stance phase of gait [B,C]. They provide a more normal gait because they permit dorsiflexion in stance, thus making it easier to walk on uneven surfaces and stairs. This is the best AFO for most ambulatory patients. Adjust the plantar flexion stop in 3-7o dorsiflexion [D] to control knee hyperextension in stance in children with genu recurvatum. The hinged AFO is contraindicated in children who do not
have passive dorsiflexion of the ankle because it may force the midfoot joints into dorsiflexion and cause midfoot break deformity. Knee flexion contractures and triceps weakness are other contraindications where a hinged AFO may increase crouch gait [E].

Knee orthoses
Knee orthoses are used as resting splints in the early postoperative period and during therapeutic ambulation. There are two types of knee orthoses, the knee immobiliser and the plastic knee-anklefoot-orthosis (KAFO). The use of such splints protects the knee joint, prevents recurrence after multilevel lengthening and enables a safer start to weight bearing and ambulation after surgery.

Knee immobilisers: Knee immobilisers are made of soft elastic material and holds only the knee joint in extension, leaving the ankle joint free. Consider using them in the early postoperative period after hamstring surgery and rectus transfers.

Plastic KAFOs: Plastic resting KAFOs extend from below the hips to the toes and stabilize the ankle joint as well as the knee. They are more rigid and provide better support to the ankle and the knee in the early postoperative phase. Knee-ankle-foot orthoses with metal uprights and hinged joints (KAFOs) were developed and used extensively in the 1950s and 60s for children with poliomyelitis. Though KAFOs are still used for ambulation in poliomyelitis and myelomeningocele where there is a need to lock the knee joint, they are not useful for the child with CP because they disturb the gait pattern by locking the knee in extension in the swing phase. Donning the KAFOs on and off takes a lot of time and they are difficult to wear. For these reasons, KAFOs for functional ambulation have disappeared from use in children with CP. Use anti recurvatum AFOs or GRAFOs for knee problems in ambulatory children.

Foot orthoses (FO)
Foot orthotics do not prevent deformity. They provide a better contact of the sole of the foot with the ground.

Supramalleoler orthosis (SMO): Extends to just above the malleoli and to the toes [A,B]. Consider in mild dynamic equinus, varus and valgus instability.

University of California Biomechanics Laboratory Orthosis (UCBL): Medial side is higher than the lateral, holds the calcaneus more firmly, supports the longitudinal arch [C]. Prescribe in hind and midfoot instability.

Heel cup Holds the calcaneus and the surrounding soft tissue, ends laterally underneath (trim lines are below) the malleoli and proximally ends at the metatarsals. Use in cases of mild subtalar instability causing varus or valgus deformity.

Hip abduction orthoses. Consider using hip abduction orthoses in children with hip adductor tightness to protect hip range of motion and prevent the development of subluxation. It is easier and cheaper to use a simple abduction pillow. Use mainly at night or during periods of rest. There is no scientific evidence to support the belief that they prevent subluxation. One clear indication for hip abduction orthoses is the early period after adductor lengthtening.

Spinal orthoses
There are various types of braces used for spinal deformity [D]. None of them alter the natural history of scoliosis in children with CP. Do not aim to stop the progression of scoliosis by prescribing a brace. Contrary to idiopathic scoliosis, the deformity continues to progress even after skeletal maturity in CP. Therefore, most children with scoliosis need spinal surgery to establish and maintain sitting balance in the long run. Prescribe a brace for the time period until surgery to enable the child to grow as much as possible. An important indication for using a brace in a spinal deformity is to provide better sitting balance [E]. A thoracolumbosacral brace helps the child sit better during the growth spurt period when spinal deformity becomes apparent, progresses fast and the child outgrows custom molded seating devices quickly. Children who are not candidates for surgery for different reasons may use spinal braces instead of seating devices for better sitting. Patients with mild and early scoliosis tolerate brace without difficulty. The brace should not be too difficult for the child to put on and take off should not compress the chest too tight and should be properly ventilated for comfortable use.

Upper extremity bracing
The indications of bracing in the shoulder and elbow are very limited. An example of a resting splint is a thermoplasticresting elbow, wrist and hand splint which keeps the wrist in 10o extension, the metacarpophalangeal joints in 60o flexion and the interphalangeal joints in extension. This type of splint is used at night and during periods of inactivity with the hope of preventing deformity. An example of a functional splint is an opponens splint [B] to bring the thumb out of the palm of the hand, allowing for better grasp. This type of splint is used in every day activities. Hand orthoses may inhibit the active use of the extremity. They also effect sensation of the hand in a negative way. Use them only in the therapy setting or at school and take off during other times in the day.