The SplintER Series is back with its second installment! In the first post, Splint 101, we discussed the indications and relative contraindications to splinting. In this post, we focus on the materials used in splinting and some key steps in splint application.

Learning Objectives

  1. List the materials that are required to place a splint.
  2. Be able to discuss some basic principles about the application of a splint.

The Bottom Line

A splint consists of 3 layers:1

  1. Deep layer = padding
  2. Middle layer = splint material
  3. Outer layer = compressive dressing

There are 2 types of traditional splinting material – plaster and fiberglass. Plaster allows for more malleability, whereas fiberglass is more lightweight and easier to apply. There are also prefabricated splints such as Ortho-Glass®.

To apply a splint:

  1. Place your stockinette (optional) and padding loosely.
  2. Submerge your material in water to generate an exothermic reaction that will harden your splint.
  3. Use your palm to conform the material to the extremity.
  4. Wrap the elastic bandage from distal to proximal and form the desired shape of your splint.

Although it is important that a splint fits to the extremity, it is equally important that it is not so tight that it obstructs venous outflow. Recall that a splinted limb is at risk for compartment syndrome. Be sure to perform a neurovascular exam before and after placing a splint.

For a concise instructional summary, the EMRA Splint Guide is extremely useful.

More Detailed, Step-Wise Instruction on Splint Application

  • Splint material: plaster or fiberglass
  • Stockinette and/or splint padding
  • Bucket of water
    • If plaster: Tepid water
    • If fiberglass: Cool water
  • Elastic bandage, such as ACE or Kerlix wrap
  • Trauma shears
  • Tape

First published in 1852 by a military surgeon named Antonius Mathijsen [2], plaster (of-Paris) has been used for over a century in order to immobilize fractures. It was the only true rigid splinting material available until the advent of fiberglass in 1987. More recently, prefabricated splints such as Ortho-Glass are available. This post focuses on the traditional method to forming a splint from plaster or fiberglass.

Given the layering and formed paste, plaster can be more difficult to apply. However, it is more malleable. Fiberglass, while less flexible, hardens quickly, is easier to apply, and is lightweight [3]. The newer prefabricated splints such as Ortho-Glass contain fiberglass and are pre-padded. Unlike traditional plaster and fiberglass, these pre-padded fiberglass splints require only a minimal amount of cool water to activate. The selection of splint material will depend on provider preference and institutional availability.

Ortho-Glass® splint material (Photo Credit: William Denq)

The use of a stockinette can be useful in protecting the skin from the sharp edges of splinting material. It prevents chafing and helps to maintain the shape of the splint. However, if the stockinette is too loose or the wrong size, the material can collect together and create pressure points, which increase the risk of skin ulceration. If the stockinette gets wet, it can cause skin maceration. Typically, a stockinette is not required for a simple splint – padding is enough to protect the skin.

Stockinette (Photo Credit: William Denq)

Padding is required for both plaster and fiberglass media. It provides a comfortable medium between the skin and rigid splint, while also preventing skin maceration [4]. Padding, like the rigid splinting material, is categorized by its width, usually 3, 4, 5, or 6 inches.

Soft padding (Photo Credit: William Denq)

Evaluate for bony prominences, and adequately pad these areas, which are prone to forming pressure sores. Examples include the olecranon, malleoli, and calcaneus [2]. Applying additional strips of padding to these areas avert the need to place an additional circumferential wrap.

Water temperature affects how fast the splinting material hardens [4]. If the water is warmer, the material will harden faster. However, the quicker the material hardens, the greater potential for a serious burn. Never use warm or hot water for plaster. Utilize cool water with fiberglass as it inherently hardens faster than plaster. Tepid water should be be used to activate plaster. Be sure to change the water you use after each splint application because the residual splint material can accelerate the activating and hardening process [2].

Use tepid or cold water for plaster or fiberglass, respectively. (Photo Credit: William Denq)

Before You Splint

Neurovascular Exam: Before applying a splint, perform a neurovascular exam, findings should be the same before and after splint application.

Expert: Dr. Elizabeth DelasoberaTips on the Neurovascular Exam

Sports Medicine Fellowship Director
Georgetown University

  1. Check and document all pulses in the region
  2. Check and document capillary refill on the affected and contralateral side
  3. Check and document sensation on the affected and contralateral side

Stockinette, Padding, and Splint Material

The patient’s stockinette, padding, and splint material all need to be measured out and cut to the appropriate length.

  1. Stockinette: Using your shears, cut the length to be 2-3 cm longer than the expected splint length.
  2. Padding: Using your shears, cut the length to be the same as your expected splint length.
  3. Splint material: Prepare 6-10 layers for the upper extremities and 12-15 layers for lower extremities. These layers will vary depending on the size of the affected limb. Your splint material length should be 1-2 cm longer than the length of your projected splint as splinting material shrinks when it hardens [5].


Any wounds that are on the affected limb need to be thoroughly assessed, cleaned, and appropriately dressed prior to splint application. Avoid using tape with the dressing; instead secure it with a rolled gauze being careful to avoid excessive compression.

Splinting Application Instructions

Apply the stockinette and then add 1-3 layers of padding. These should be placed circumferentially and loosely around the extremity beyond where the rigid splint is expected to be. When you run out of padding roll, half of the previous width should be covered by the subsequent, neighboring layer [5].

If splinting fingers or toes, ensure padding is placed between fingers/toes to prevent maceration. If splinting the forearm and the padding needs to traverse the thumb, create a defect in the padding to stick the thumb through.

Application of stockinette and overlying padding (Photo Credit: Caleb Sunde)

If using plaster, submerge the layers in tepid water until the bubbling stops. This signals the complete saturation of the material [3]. If using fiberglass, submerge the layers in cool water until the bubbling stops. Prefabricated splints such as Ortho-Glass should not be submerged as it only requires a minimal amount of cool water to activate the material.

The purpose of applying water to a splint material is to activate it. Doing so will cause an exothermic reaction while the material hardens. Because burns have been reported, use cooler water (as opposed to hot water), and apply generous padding. Wring out as much water as possible while still maintaining the plate-like integrity of the splint material. Place the splint on a hard surface or several layers of your pre-cut padding to smooth out any formed wrinkles.

Activating the splint by submerging in tepid water (Photo Credit: William Denq)

While keeping the extremity in its desired position, conform the material to the extremity with the palm. Fingers can create indentations and unintentional pressure points that may result in skin breakdown [4]. An assistant may be used to help stabilize the splint material onto the affected limb. To avoid accidental soft tissue damage or discomfort from the sharp ends of plaster and fiberglass, fold the edge over on itself. In general, plaster hardens in 5-10 minutes and fiberglass in 3-4 minutes.

Do NOT rest the affected extremity with a forming splint on a surface such as a pillow or table as it could trap the exothermic reaction generated and result in a burn [2].

Application of the splint over stockinette and padding (Photo Credit: Caleb Sunde)

The elastic bandage should be wrapped onto the affected extremity in a distal to proximal direction. This theoretically helps with venous return and reduces subsequent swelling from an acute injury [5]. Although the bandage application helps to conform the hardening splint material to its desired position, excessively tight application (in an effort to reduce swelling and mold the splint) may instead result in compartment syndrome.

Application of the elastic bandage should be in a distal to proximal fashion. (Photo Credit: Caleb Sunde)

After the splint application, the procedure is not yet complete.

  1. Check and document all the pulses in the region. If the occlusive dressing prevents you from being able to document these pulses. The next best assessment is to check and document the distal capillary refill and sensation exam.
  2. Check the range of motion of the unaffected joints to ensure that the splint does not interfere with their movement [1].


  1. Brown S, Radja F, eds. Orthopaedic Immobilization Techniques. Urbana, IL: Sagamore Publishing; 2015.
  2. Browner B, Jupiter J, Krettek C, Anderson P. Skeletal Trauma: Basic Science, Management, and Reconstruction. 5th ed. Philadelphia: Elsevier Saunders; 2015.
  3. Tintinalli J, Stapczynski J, Ma J, Yealy D, Meckler G, Cline D. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8th Edition. 8th ed. McGraw-Hill Education / Medical; 2015.
  4. Boyd A, Benjamin H, Asplund C. Principles of casting and splinting. Am Fam Physician. 2009;79(1):16-22. [PubMed]
  5. Roberts J R, Custalow C B, Hedges J R, Thomsen T W, eds. Roberts and Hedges’ Clinical Procedures in Emergency Medicine. 6th ed. Saunders; 2014.
Max Hockstein, MD

Max Hockstein, MD

Emergency Physician
Critical Care Fellow
Department of Anesthesiology
Emory University School of Medicine
William Denq, MD CAQ-SM

William Denq, MD CAQ-SM

Assistant Professor
Department of Emergency Medicine
University of Arizona
William Denq, MD CAQ-SM


Clinical Assistant Professor Emergency Medicine and Sports Medicine University of Arizona George Washington University '18 University of Pittsburgh '14 and '10