A low temperature splinting material
Originally prepared by:
Judith Wasserman, O.T.R.
With acknowledgements to:
Diane Shapiro, M.S., O.T.R.; Anita Simmons, O.T.R.; Irene Hollis, O.T.R.; Paula Collodi, O.T.R.; Kathy Hata, O.T.R.; Felix Rincon, C.O.; and the entire staff of Occupational Therapy and Orthotics Services at Goldwater Memorial Hospital
September 1976, revised March 1977, January 1978 and January 2000
RevealsÔ is a low temperature thermoplastic used for fabrication of splints, braces and adaptive equipment. This manual presents an introduction to the basic principles and techniques of splinting and a guide to the use of Reveals as a highly effective splinting medium.
The techniques of design and fabrication of splinting materials are used to achieve as close to normal function as possible. A knowledge of the structure and function of the body and the effects and remediation of various disease processes is closely combined with technical knowledge of equipment and materials.
Knowledge of motor capabilities and limitations as evidenced in the specific needs of each client enables skilled splint makers to provide "custom-made" devices to best meet these needs.
Purposes of Splinting
Splints serve the following purposes:
Position extremity for improved function
CLASSIFICATION OF SPLINTS
Static splints have no moving parts and hold affected portion of the limb immobilized, approximating the position of function.
Dynamic splints have moving parts such as joints, hinges or springs. Elastic tension using outriggers and finger cuffs apply forces to substitute for or counteract the effect of absent muscle power.
Positioning splits are designed to correct or prevent deformity/contracture.
Functional splints are designed to improve function and/or substitute for limited movement.
Functional and positioning splints may be either static or dynamic.
An opponens splint, which positions the thumb to improve prehension patterns, is an example of a static functional splint.
A dorsal hand splint with an outrigger designed to assist extension at the MP joints is an example of a dynamic functional splint.
A full hand positioning splint to correct or prevent flexion contractures of the wrist and fingers in an example of a static positioning splint.
A hand splint with an outrigger and finger sling exerting minimal traction on a contracted PIP joint is an example of a dynamic splint designed to correct position.
After assessment of the patient's function/dysfunction, therapists and orthotists determine the most effective splint design. They give careful consideration to the following:
An effective method of determining the above factors is as follows:
Use your own hands to simulate the support, position and forces to be exerted by the splint. While asking the patient to perform desired movements, place extremity in varying positions and provide varying areas of support.
If a particular splint may meet some needs and not others, consider providing more than one splint for differing purposes, intermittent use of splints and construction of a splint with removable parts such as a dorsal wrist support with a removable finger extension assist.
SELECTION OF MATERIALS
A wide range of materials with varying properties, advantages and disadvantages are available today for splint making. Familiarity with these materials and their properties allows the therapist or orthotist to select a material that most effectively meets the specific stability and/or mobility requirements of the patient.
The following factors are considered in the selection of materials:
CHARACTERISTICS OF REVEALS THERMOPLASTICS
Like other low temperature thermoplastics, Reveals may be molded directly against the skin. Other advantages are durability, strength and good appearance. Reveals has the following characteristics of particular interest to hand splinting:
Moldability: Reveals is a soft stretchy material, which can be easily molded to construct splints that are highly definitive and fit intimately to the fine contours of the body. Reveals Quick Bond clings to the patient's skin as it hardens, following the natural drape of the skin without displacing soft tissue. It conforms to concavities and ridges rather than bridging over them.
Transparency: When soft, Reveals is transparent, enabling the splint maker to see areas of pressure during fabrication of the splint.
Elasticity: The "stretchiness" of Reveals enables the material to be used in many creative ways, and allows latitude in pattern design.
Elastic Memory: Reveals returns to its original shape when reheated. This allows for correction of errors and reshaping.
Four thicknesses, 3/16", 1/8", 3/32" and 1/16", provide adequate support with minimum bulk, may be reinforced if necessary, provide flexible support if desired. Small or delicate hand and finger splints for children and infants may be made with 1/16" Reveals, which cuts easily without heating using ordinary scissors.
Two surfaces, sticky and non-stick. Reveals Quick Bond readily bonds to itself, and will hold in place on the patient's skin while hardening. Reveals which is coated to reduce stickiness will not accidentally bond or stick to work surfaces, clothing or hair. Temporary bonds form when two surfaces are pressed together while soft. More permanent bonds require abrading the surface with sandpaper or selectively removing the surface coating with splint solvent or nail polish remover.
Ample working time: Reveals stays soft and workable long enough to allow molding without need to reheat the material. Setting time can be hastened with ice.
Cost effective: Stretch and remoldability of Reveals provide economy in usage. Ease of splint fabrication increases the splint maker's productivity.
PROPERTIES OF REVEALS
Reveals is available in 3/16", 1/8", 3/32" and 1/16" thicknesses, smooth and perforated for ventilation. The smooth versions are available in several degrees of pliability or memory when soft. Reveals has a non-stick surface coating. Reveals Quick Bond is uncoated for instant bonds to itself when softened. Reveals Quick Bond will hold in place on the patient's skin while hardening, but will not bond permanently to skin, or to any cold, wet or lubricated surface.
Reveals 1/16" thick remains moldable for one to two minutes. Reveals 3/32" remains moldable for two to four minutes. Reveals 1/8" remains moldable for three to five minutes, depending on room temperature, airflow, and to a certain extent water bath temperature. Reveals will hold its shape in eight to ten minutes but will not reach full rigidity for 15 to 20 minutes. Reveals 3/16" or double thicknesses of 1/8" material such as spines and overlaps require up to an hour to harden completely at room temperature, but may be quenched in ice water for about a minute to speed hardening. Edge finishing is best accomplished by trimming the splint with a sharp pair of scissors during the final cool-down phase.
Reveals splints may be quick set with cold water, an ice pack, aerosol coolant or a fan.
Reveals splints may be repeatedly reheated and reshaped to adjust for changes in client needs, edema or weight loss.
Reveals splints are lightweight, strong and durable, pleasing in appearance and easy to keep clean.
With unlimited shelf life, Reveals splints may be expected to last for a minimum of one year in normal use.
Keeping in mind factors listed under Splint Design (Page 4), select a published pattern or design a custom pattern for the patient.
To adopt a published pattern design:
To custom design a pattern:
Transfer pattern onto Reveals
How to cut Reveals
How to soften Reveals
Molding Reveals Splints
Finish Splint Edges
Try these techniques to find which works best for you.
Determine points of attachment. Manually simulate strap supports with your hands, then place strap (Velcro or webbing) in various positions to determine most effective placement of straps to secure splint.
Angle the straps unless the extremity is cylindrical at the point of strap attachment. Straps are placed at an angle so they contour to the irregular shape of the limb.
Wide straps distribute pressure more evenly than narrow straps. Wide straps (2 or 4 inches wide or even wider) may be used over large fleshy areas or across long bones, such as upper forearm, thighs or upper leg. Narrower straps may be used in smaller areas such as the hand or wrist. Select straps as wide as is practical for the application.
Application of self-adhesive hook Velcro
Hook Velcro faces away from the skin. Usually hook Velcro is applied at the two points of strap attachment on the outside of the splint, and Velcro loop, Velfoam or Beta Pile strap is used as a removable strap across the two attachment points. This simplifies laundering or replacement of the straps when soiled.
Webbing is sometimes used to save cost, or for unreliable clients who might loose their detachable straps. Webbing straps can be anchored at one end with a metal or plastic rivet, or be embedded into the splint by covering one end with a strip of softened Reveals, after spot heating the point of attachment with a heat gun. A hole cut in the webbing acts to further anchor the strap.
Apply lining if desired, for clients with fragile skin or under perforated splints to wick perspiration, or when splinting over bony prominences. In most cases the lining should be easily removable and replaceable. Be sure to make the splint large enough to accommodate the extra material. Either spread the splint after completion or mold the splint over padding or dressings on the limb. Moleskin patches may be applied to bony prominences prior to molding the splint, then reversed and applied inside the splint when the splint is completed.
If a splint is causing pressure, padding the pressure area will make the pressure worse. Spot heat and remold the problem area of the splint to relieve pressure.
Perforated Reveals may be used for ventilated, lightweight splints, but the edges are harder to finish. A leather punch can be used to create some ventilation in a solid splint.
To self adhere Reveals after your splint is molded, such as for attachment of an outrigger, spot heat both surfaces with a heat gun until one surface is soft to conform to the other surface, and the other surface is tacky but not soft. Two tacky surfaces will stick to each other. Splint solvent or lacquer thinner may be used as solvent adhesives, but are usually not necessary.
When re-softening part of a splint in a deep water bath such as a Hydrocollator, move the splint up and down 1-2" as it softens to prevent unevenness when remolding.
Reveals shrinks 2% as it cools, equivalent to 1/4" per foot, which is usually accommodated by the soft tissue. However, you should allow for shrinkage when splinting over bony prominences or around interphalangeal joints. Run your finger under the splint as it cools to dome out over bony prominences, and around the edges of the splint to prevent the edges from pressing in. Stretch finger loops so they will be loose enough to slip over IP joints when the splint hardens.
HAND/WRIST POSITIONING SPLINT
Us 1/8" Less Stretch Reveals for this splint
The designs that follow may be made with 3/32" or 1/16" Reveals to minimize bulk and allow better function.
A rectangular strip of Reveals, approximately 1 1/2" x 8", is wrapped around the web space, thenar eminence and either dorsum or palm.
WRIST POSITIONING SPLINTS
In general, 1/8" Reveals is used but 3/32" or 1/16" is suitable where flexibility is desired. The splint is designed to stabilize, support or
position the wrist for improved hand function and position.
Lumbrical bars on splints serve to stabilize the Metacarpal Phalanges joints, prevent MP hyperextension, and allow Proximal Interphalanges joints to extend fully, either actively or with PIP extension assists.
Outriggers are used to provide a point of attachment for finger slings. Outriggers may be made from Contour Tubes, brass welding rods, or strips of Reveals folded over a wire form. Position the outrigger so the point of finger sling attachment is perpendicular to the desired direction of pull.
Tension is applied to the finger sling by a rubber band, elastic thread or spring. When using rubber bands, choose an appropriate length and width so that the tension is applied over the mid-range of the rubber band when the joint moves through its maximum range of motion. The same principal applies to springs and elastic thread.
Long opponens splint with lumbrical bar (MP stop) and PIP extension assist. Outrigger is shaped of brass welding rod and embedded in Reveals Pellets.
HINGED WRIST EXTENSION ASSIST FABRICATION PROCEDURE
Dynamic hinged wrist extension assist with
opponens and thumb MP extension support.
Mold forearm piece, fold back wrist edge and sidepieces to double thickness. Leave tabs to attach opponens splint.
Soften tab. Heat surface of opponens at adhering points. Check that the sidebars are centered and level. Attach opponens.
Determine the axis of wrist joint by putting the splint on and moving patient's hand hand up and down at wrist between flexed and neutral positions. The point that stays centered on the sidebar is the axis point. The radial side of the wrist joint will have a slightly different axis point than the ulnar side. Determine the axis points one side at a time and mark the axis point on both sides of each sidebar.
Remove the splint from the patient's hand. Spot heat with a heat gun at the axis points. Pinch one axis point with needle nosed pliers while pointing the pliers at the opposite axis point. Pinch the opposite axis point while pointing the pliers at the first axis point. Fold the hinges formed back and forth sharply several times, making sure the two hinges on either side of the wrist move smoothly.
Apply the hook on the center of the dorsal surface of the opponens and the look at the proximal end of the forearm piece. Connect rubber bands between the hook and loop. Adjust tension by adding or shortening the rubber bands, and by choosing heavier or lighter rubber bands until you find the right tension to raise the patient's wrist into full extension, yet do not limit active flexion. Be sure the rubber bands are working near their mid-range, not near their elastic limit.
WRIST HINGE SPLINT #2
This splint may be made with metal or plastic screw rivets through holes punched in flat strips of Reveals.
Cut two side bars 7/8" wide to extend 2/3 of the forearm. Cut three cross strips as illustrated. Form the palmar opponens piece with wrist tabs using the pattern on the back cover.
Palmar opponens piece with wrist tabs
Place a softened strip of Reveals across the dorsum of the wrist and adhere to the opponens piece.
Hinge tabs should be flat and parallel to each other so the hinge moves freely. Rivet hole should be large enough to insert the rivet loosely. Allign inner surfaces of side supports with sufficient clearance to permit free movement.
HINGED ULNAR DEVIATION SPLINT
Ulnar deviation splint with hinge formed by rivets. Two-part screw rivets (aluminum or plastic) are recommended. Thread strap through loops on finger dividers.
A splint to limit extension of the PIP joint.
Cut a 1"x1 1/2" rectangle from 1/16" Reveals. Punch two holes with a leather punch using the largest hole diameter punch available. The centers of the holes should be as far apart as the width of the patient's PIP joint. Trim the corners and soften in hot water.
Lubricate the patient's finger with hand lotion or water. Stretch the splint over the finger with one hole at the proximal phalanx level and the other hole over the middle phalanx.
Mold the sides down while holding the joint in about 10 degrees of flexion. Spread B and C as far apart as possible for maximum leverage on the joint and for ease of removal, particularly if the PIP joint is enlarged.
This splint may also be made from 3/16" diameter Contour Tube. Soften a piece of Contour Tube about 1 1/2 times the length of the finger. Press the softened ends together, forming a loop. Twist the loop 180 degrees forming a figure 8, with the joined ends in the middle of the 8. Pinch the middle of the 8 where the center of the Contour Tube overlaps the joined ends.
Thread the finger through the figure 8, so that one loop of the 8 is over the proximal phalanx and the other loop over the middle phalanx, with the center of the 8 under the PIP joint. Spread the loops as far apart as possible over the proximal and middle phalanges, while keeping the overlap centered under the PIP joint. Hold the joint in about 10 degrees of flexion while the splint hardens. Hardening may be accelerated with a fan or cold spray.
Transparency of Reveals when soft is advantageous when making splints for burn patients to assure close skin contact with no voids beneath the splint. Be careful to avoid adhesion of softened Reveals to new grafts, fragile scar tissue or bandages. KY Jelly or vaseline on the patient's skin or on the splint's patient side eliminates the slight surface stickiness of softened Reveals. If the patient has recent sutures, place wet or Vaseline gauze 4x4's over the site before splinting.
Extra Stretch Reveals is very limp and pliable when soft and conforms well for a close fit to neck, axilla and facial contours.
Moderate Stretch Reveals conforms well for trunk and extremity burn splints. Less Stretch Reveals should be used when attempting to reduce seasoned hypertropic scarring. It is quite firm when soft and effectively flattens scar tissue.
For correction or prevention of foot drop.
Foot splint may also be made from one piece of Reveals.
For ambulatory patients a "leaf spring" below knee orthosis (BKO) may be made by stretching around the heel without forming darts and trimming the foot to allow some dorsiflexion as the patient walks. This splint may be worn inside of a sneeker or sandle.
An effective method of strapping foot splints is a figure 8 of 1 1/2" webbing around the ankle and attached to Velcro at the instep and top of Achilles tendon. Use a 2" strap around the top of the splint as illustrated.
Reveals sheets, pellets and tubes readily bond to themselves and other materials, and resist soiling, making them ideal for custom made adaptive equipment. Perforated Reveals is well suited for light weight non-slip built-up handles.