Alternative And Complementary Therapies Casts, Splints, and Orthoses - Lower Extremity

Keeping Current © Rachel Teplicky, Dianne Russell, Mary Law, 2003

Support for the research to conduct this review comes from a grant from The EconoEconomical Insurancemical Insurance Group

Review of effectiveness literature for children with neurological disorders

This Keeping Current is one of a series of reports that discuss the effectiveness of rehabilitation interventions for children and youth with brain injury.

When reading the Keeping Currents in this series, you will notice that they include research studies that involve children and youth with a variety of conditions. These studies were included because of the limited amount of research on rehabilitation interventions for children and youth with brain injury.

We encourage you to be critical when deciding what information relates to your situation. The most relevant information will come from studies that address the specific condition in question. However, be aware that research findings from studies involving children with different conditions may be relevant when the causes of the conditions are similar ( for example, brain injury and cerebral palsy are both caused by injury to the brain) or when the children's functional difficulties are the same.

Introduction

Children who have a neurological condition, such as cerebral palsy or brain injury, often have difficulty moving their body. Muscle spasticity is one of the most common reasons for this difficulty.

Spasticity is present when a muscle is stretched and it responds by contracting abruptly (that is, the muscle moves quickly in the opposite direction of the stretch). When a child with spasticity tries to move or when someone tries to move the child, the motion is limited and often a tremor occurs. In the long term, this limited movement can cause children's muscles to grow at a slower rate than the bones to which they are connected. This can lead to muscle contractures and reduced range of movement.

There are many techniques used to help children overcome the difficulties caused by spasticity, including therapy, drugs, and occasionally surgery. In addition to these techniques, casts, splints, and orthoses are often recommended. This research summary will explore the use of casts, splints, and orthoses for the lower extremity for children who have spasticity. A review for the upper extremity is also available from CanChild.

What are Casts, Splints, and Orthoses?

Casts, splints, and orthoses are all devices that are designed to keep the body in a certain position. These devices are used to prevent or correct deformities and/or to help children overcome activity limitations, such as difficulties with standing and walking. The International Organization for Standardization (1998) has recommended that the term "orthoses" be used for all of these devices. This organization defines orthoses as, "externally applied devices used to modify the structural and functional characteristics of the neuro-muscular and skeletal systems by applying forces to the body". However, in clinical practice, the terms casts, splints, and orthoses are still commonly used. The following paragraphs describe the differences between the three devices.

Casts are made of plaster or fiberglass, the same materials used to cast broken bones. They may be solid or removable (that is, cut in half down the length of the cast to allow removal for periods of time). Casts are usually applied for periods between 2 and 6 weeks. Sometimes they are removed and reapplied to increase the stretching effect on the muscles when improvement has been observed. This is referred to as serial casting.

Splints are commonly made out of plastics that can be heated and moulded directly onto the body. They can be produced quickly; however, the plastic is often not very strong. As such, splints are usually recommended only when the device is needed for a short time, or when there is not much force placed on the material.

Orthoses for children with neurological conditions are usually custom-made. Very high temperatures are needed to mould the material used to make orthoses and as a result, orthoses are usually based on plaster models of the child's body. Although orthoses take longer to make than splints, they are more durable and can be used for longer periods of time.

How do Casts, Splints, and Orthoses Work?

Casts, splints, and orthoses work by applying forces to the body. By encompassing parts of the body and preventing movement, muscles and joints can be stretched. Many muscles cross two joints (for example, the calf muscles cross both the ankle and knee). To exert a stretching effect, either both joints must be held by the device or activities that stretch the joint that is not in the device should be encouraged. Casts, splints, and orthoses can also provide stability to help some children stand and walk. This is the biomechanical explanation for why these devices work.

The forces that casts, splints, and orthoses apply on the body are usually reactive (that is, they prevent movement by resisting the forces that the body generates). However, muscles lengthen more efficiently in response to active forces. New developments in orthotic design are using compressed gas pistons or coiled springs to generate active forces. These techniques still need to be evaluated, but may be more effective at correcting established joint contractures.

Finally, there has been a lot of interest in additional design features for casts, splints, and orthoses that are proposed to affect spasticity or change muscle tone. These concepts have been termed tone-reducing, inhibitive, neurophysiological or dynamic casts, splints or orthoses. Although they are promoted by some clinicians and have been widely adopted in centres around the world, there is not yet any evidence to support any additional benefit over the biomechanical design into which they are incorporated.

What do We Know About the Use of Casts, Splints, and Orthoses for Children with Spasticity?

Review Methodology

A literature review was completed to find information about casts, splints, and orthoses. Electronic databases (Medline, CINAHL, and EMBASE) were searched using the following keywords: cerebral palsy, brain injury, splint, splinting, cast, casting, and orthoses. This literature review was completed in September, 2001.

Published journal articles were considered for inclusion in this review if they reported on the use of casts, splints, or orthoses for the lower extremity for children with brain injury or cerebral palsy. Studies with the highest quality designs (based on guidelines from the field of clinical epidemiology) were included.

After our review was completed, another author published a review of lower-limb orthoses for children with cerebral palsy (see Morris, 2002). In his review, Morris accessed a wide range of databases and included published abstracts in addition to journal articles. This comprehensive review is recommended for people who are interested in learning more about the use of orthoses for children with cerebral palsy.

Effectiveness of Casting

A number of studies have shown that serial casts (Brouwer et al., 1998; Cameron & Drummond, 1998) and inhibitive or tone reducing casts (Otis et al., 1985; Tardieu et al., 1982; Watt et al., 1986) can improve ankle movement (specifically ankle dorsiflexion - foot movement toward the shin) in children with cerebral palsy. The long-term effects of casting on ankle movement are less clear. One study followed children with cerebral palsy for an average of three years after casting. It was found that some of the children maintained the improvements and others did not (Cottalorda et al., 2000). The authors reported, however, that casting was effective in delaying the need for the children to undergo surgery to lengthen their muscles.

The impact of casting on children's walking patterns has also been studied. Serial casting (Cameron & Drummond, 1998) and inhibitive casting (Bertoti, 1986; Hinderer et al., 1988) have been shown to increase the length of steps taken by children with cerebral palsy. Serial casting has also been shown to decrease toe-walking in children with cerebral palsy (Brouwer et al., 2000). Brouwer at al. found that following casting, all of the children with cerebral palsy who had been toe-walkers were able to make contact with their heel on the ground when walking - at the six week follow-up, these results were maintained in six of the eight children.

Two studies have compared the effects of casting with those of Botulinum Toxin (BTA) - refer to the CanChild Keeping Current on BTA (KC #02-1) for more information on this intervention. Both of the studies found that casting and BTA had similar effects on decreasing muscle tone and ankle movements (Corry et al., 1998; Fleet et al., 1999). However, BTA was reported to have longer lasting effects and to be preferred by the parents in the study.

Effectiveness of Orthoses and Splints

In the last five years, a number of studies have been published in this area. The main focus of the research has been to compare the effect of different orthoses on ankle movements and walking patterns of children with cerebral palsy. The most common type of orthosis studied is the ankle-foot orthosis (AFO).

AFOs are typically designed to limit unwanted ankle movements, specifically ankle plantar flexion (foot pointed toward the ground). AFOs can be fixed (to block ankle movement) or articulating (to allow for some movement at the ankle).

Preventing plantar flexion through the use of AFOs has been found to improve walking efficiency in children with spastic diplegic cerebral palsy (Carlson et al., 1997; Crenshaw et al., 2000; Radtka et al., 1997; Rethlefsen et al., 1999) and in children with hemiplegic cerebral palsy (Buckon et al., 2001). Supramalleolar orthoses (SMO), which do not cross the ankle joint, do not prevent toe-walking (Carlson et al., 1997; Crenshaw et al., 2000)

When AFO use is compared to barefoot walking, the children's walking patterns are better when wearing AFOs (Buckon et al., 2001; Radtka et al., 1997). Ankle movement and walking patterns have been shown to deteriorate when children who typically wear AFOs did not wear them for a two-week period (Hainsworth et al., 1997).

For children with cerebral palsy who tend to walk on their toes, AFOs have been shown to improve their ability to move from sit to stand (Wilson et al., 1997). However, children with cerebral palsy who are able to stand on a flat foot did not benefit from AFOs for moving from sit to stand as the AFOs tended to slow them down.

AFOs have also been shown to affect how much energy children with cerebral palsy use to walk. Maltais et al. (2000) found that children with spastic diplegic cerebral palsy had lower oxygen needs during walking when they wore hinged AFOs. They did not find a change in heart rate, however, a small change in heart rate was found in a study by Mossberg et al. (1990). Buckon et al. (2001) found that certain AFO designs allowed children with hemiplegia to walk faster without increased energy cost.

The Gross Motor Function Measure (GMFM) has been used to evaluate the effect of AFO use on gross motor skills. Evans et al. (1994) evaluated two groups of children with cerebral palsy - one group received physiotherapy and AFOs, the other group only received physiotherapy. Both groups had similar improvements in gross motor skills, suggesting that the AFOs did not affect gross motor development. In two other studies, no effects on gross motor skills were found in children with spastic diplegic cerebral palsy (Maltais et al., 2000; Buckon et al., 2001). However, use of AFOs did improve coordination and weight shift as assessed by the Gross Motor Performance Measure (Buckon et al., 2001).

One study was identified that investigated the use of splints with children who have had a brain injury. Mills (1984) found that the splints or casts significantly improved the resting position of the ankle, wrist and/or elbow in individuals aged 7-22 years. There was no significant difference in muscle tone whether the splint was on or off, suggesting that casts and splints can be used to improve joint position without the fear of increasing muscle tone. The use of this information is limited, however, as the author did not indicate the subjects' stage of recovery.

Summary

This literature review has outlined research on the use of lower extremity casts, splints, and orthoses. For children with brain injury, there has been very little exploration of the effectiveness of casts, orthoses and splints. The one study reported in this review did suggest that splints and casts are beneficial, however, not enough information was provided to judge who would likely benefit.

For children with cerebral palsy, casting has been shown to improve ankle range of movement, with effects that are similar to those found with Botulinum Toxin treatment. Ankle foot orthoses (AFOs), which cover the ankle and extend to the knee, have been shown to be effective in limiting ankle plantar flexion during walking and in increasing the child's walking efficiency. Researchers have begun to explore the effect of AFOs on a number of other areas including, energy needs and gross motor skills.

However, the research that has been conducted in this field is not without limitations. One limitation is that the majority of studies have only explored the short term use of casts and orthoses. The long-term effects of these interventions are not yet known. Another limitation is that children and youth with brain injury or cerebral palsy often receive a variety of interventions, which makes it difficult to determine the exact effect of the intervention being studied.

The above limitations suggest issues that should be considered in future research studies on the use of casts, splints, and orthoses. In addition, researchers should also continue to focus on how these interventions affect important aspects of children's lives, such as their ability to take part in everyday activities. Such information will help families and service providers make choices about the use of casts, splints, and orthoses.

Update written by:

Rachel Teplicky, OT Reg. (Ont.), BHSc (OT), Project Coordinator, CanChild

Dianne Russell, MSc, Associate Professor, School of Rehabilitation Science, McMaster University and Research Coordinator, CanChild

Mary Law, Ph.D., OT Reg. (Ont.), Professor and Associate Dean (Health Sciences) Rehabilitation Science, McMaster University, Co-director, CanChild

Want to know more? Contact:

Mary Law
CanChild Centre for Childhood Disability Research
Institute for Applied Health Sciences, Room 408
1400 Main St. W., Hamilton, ON L8S 1C7
Tel: 905-525-9140 x 27850 Fax: 905-522-6095