Casts, Splints, and Orthoses - Upper Extremity Review of effectiveness literature for children with neurological disorders

Keeping Current © Teplicky, R., Russell, D. & Law, M., 2003 

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

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 upper extremity for children who have spasticity. A review for the lower extremity is also available from CanChild.

What are Casts, Splints, and Orthoses?

Casts, splints, and orthoses are all devices that are designed to maintain 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 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 diagnoses are usually custom-made. Very high temperatures are needed to mold 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, Orthoses and Splints 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 usually apply are reactive (that is, they prevent movement by resisting the forces generated by the body). 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, Orthoses and Splints for the Upper Extremity?

Review Methodology

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

Published journal articles were considered for inclusion in this review if they reported the use of casts, orthoses or splints for the upper 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.

Effectiveness of Casting for the Upper Extremity

A few studies have explored changes in upper extremity range of movement following a period of casting. For children with cerebral palsy (Copley et al., 1996; Law et al., 1991) and children with traumatic brain injury (Hill, 1994) range of movement was increased at the joint that was held in the cast (either the wrist or the elbow). Two of these studies also found that casting decreased muscle tone (Copley et al., 1996; Hill, 1994).

Conflicting results have been found in studies measuring the quality of upper extremity movement after casting. Quality of movement was improved in one study (Law et al., 1991), but not in another (Law et al., 1997). Law et al. (1997) suggest that different results were found because of the age of the children involved in the two studies - quality of movement appears to be more sensitive to change in children older than four years.

The effect of casting on children's ability to use their hands has also been studied. Hill (1994) found that there was no difference in individuals' ability to do functional activities after casting. Law et al. (1997) found that occupational therapy that focussed on functional activities was as effective as intensive neurodevelopmental therapy and casting combined. Copley et al. (1996) reported changes in functional goals after casting, however, few of these goals actually addressed functional hand use (the majority of the goals were related to impairments such as movement or pain).

Table 1 provides further details about studies discussed in the last three paragraphs.

Effectiveness of Splints and Orthoses for the Upper Extremity and Trunk

The few studies that have been completed in this area have focussed on how the splint or orthosis affects grasp and hand use. Two studies have shown that various hand splints can improve the grasp of children with hemiplegic cerebral palsy (Exner & Bonder, 1983; Flegle & Leibowitz, 1988). Reid and Sochaniwskyj (1992) found that a specially designed hand splint did not significantly change the children's ability to reach or to do a pencil and paper task (which was designed to evaluate visual-motor function).

The use of a specific soft elbow splint was found to significantly increase elbow range of movement for one child who was in a coma following a traumatic brain injury (Mackay & Wallen, 1996). Although this study evaluated only one child, it is a replication of a previous study by the authors (Wallen & MacKay, 1995), which adds to the strength of the findings.

Therapists also use neoprene, a thick stretchy material, for upper extremity splinting. Only one study was found that evaluated the use of neoprene splints. Blair et al. (1995) found that wearing a neoprene body suit - the UPsuit - improved the postural stability and upper extremity movements of some children with cerebral palsy. However, it is unclear from the study design how many children would benefit from an Upsuit.

Table 2 provides more details about the studies discussed in the above paragraphs.

Summary

There is very little research reported in the literature on the use of upper extremity casts, splints, and orthoses for children with cerebral palsy or brain injury.

From the research that has involved children with cerebral palsy, it appears that hand splints can improve grasp, and that casts can increase range of motion and decrease muscle tone. Studies have not demonstrated, however, that casts or splints are able to improve children's ability to use their hands. This information is useful for parents and service providers because it suggests that there are goals for which casts, splints, or orthoses are more effective.

Less is known about the use of casts, splints, and orthoses for children with brain injury. However, there is preliminary evidence that soft elbow splints can increase range of motion when applied soon after the injury and that casting may be effective in increasing range of motion.

As can be seen from this review, the research in this area is very limited. As some therapists currently recommend the use of casts and splints, it is important that further research be conducted in this area to allow therapists and families to make informed decisions about whether or not to try casting or splinting.

Prepared 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

Table 1: Effectiveness of Casting for the Upper Extremity

Table 2: Effectiveness of Splints and Orthoses for the Upper Extremity