Posterior Long Arm Splinting 

Updated: Aug 06, 2021
Author: Lisa Jacobson, MD; Chief Editor: Erik D Schraga, MD 



Posterior long arm splinting is used in the management of multiple upper-extremity injuries.[1, 2] Splints stabilize injuries by decreasing movement and providing support, thus preventing further damage. Splinting also alleviates extremity pain and edema and promotes soft-tissue and bone healing. Splints can be used either for immobilizing an extremity before surgical treatment or as a temporizing measure before orthopedic consultation.

Unlike casts, which are circumferential, splints are often the treatment of choice in the emergency department (ED) because they allow for swelling that may be present at the site of injury and thereby decrease the risk of compartment syndrome. After a splint is placed, follow-up for definitive care with an orthopedist should occur within 1-5 days.[1]


Upper-extremity injuries for which posterior long arm splinting is indicated include the following[1] :


There are no absolute contraindications for posterior long arm splinting. However, there are certain injuries that, though not constituting actual contraindications, call for immediate evaluation or intervention by a consultant. Patients with the following injuries should not undergo splinting and should be discharged home for follow-up:

  • Multiple or complicated fractures
  • Open fractures
  • Injuries associated with neurovascular compromise

Periprocedural Care


Equipment employed in posterior long arm splinting includes the following:

  • Bucket
  • Water source
  • Cast padding (eg, Webril [Covidien, Mansfield, MA]) that is wider and longer than the casting material used
  • Plaster or fiberglass casting material (~10 layers of plaster are recommended for upper-extremity splints)
  • Stockinette
  • Elastic bandage (eg, Ace wrap)
  • Sling

Patient Preparation


Ensure adequate analgesia for the patient throughout the splinting procedure and afterward. Patients often experience significant improvement in pain symptoms after a splint is placed. With the administration of any analgesic agent or the initiation of a formal sedation protocol, care should be taken to avoid oversedation. A complete neurovascular examination should be performed before and after the splint has been applied.

Acceptable analgesic techniques include the following:

  • Administration of a hematoma block or nerve block
  • Procedural sedation, administered by an experienced practitioner with appropriate monitoring in place
  • Administration of oral or intravenous (IV) pain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs) or opioid analgesic agents

Controversy exists regarding whether NSAIDs delay bone healing.[8, 9] To date, studies have been inconclusive on this point; however, most orthopedists and emergency medicine practitioners continue to use NSAIDs in the treatment of fractures. Because of the potential risk of delayed healing and other complications, the clinician may want to choose non-NSAID analgesics in cases of confirmed fractures.

In 2008, Vuolteenaho et al noted that “the clinical significance of the effect in various patient groups needs to be carefully assessed and further investigations are needed to characterize the patients at the highest risk for NSAID-induced delayed fracture healing and its complications. In the meantime, use of NSAIDs in fracture patients should be cautious, keeping in mind the benefits of pain relief and inhibition of ectopic bone formation on one hand, and the risks of non-union and retarded union on the other hand.”[10]


Prepare the patient. Remove all jewelry and clothing on the affected extremity. Place the patient in a comfortable position. Drape the patient with a sheet to ensure cleanliness. Completely expose the affected limb.

Complete and document a thorough examination both before and after splinting. Document the neurovascular examination, as well as the wound/skin examination.



Application of Posterior Long Arm Splint

The posterior long arm splint should extend from the axillary crease to the wrist joint but should not include the metacarpals. It should cover the posterior surface of the arm behind the elbow.[11] The steps in splinting are as follows.

Apply the stockinette like a sleeve over the affected limb (see the video below).

Posterior long arm splinting. Measuring and placing sleeve.

Wrap the cast padding around the stockinette (see the video below). Use padding that is wider and longer than the plaster (or fiberglass) will be. Apply minimal extra padding to bony prominences and pressure points. Apply in a distal-to-proximal fashion.

Posterior long arm splinting. Applying cast padding.

Measure the appropriate length of plaster (see the video below). The simplest way to measure is to drape the stockinette over the appropriate part of the upper extremity and cut 5 cm extra on either side. Make the plaster slightly shorter than this template.

Posterior long arm splinting. Measuring plaster.

Tear 10 sheets of plaster. Submerge the plaster in water until no more bubbles appear. Squeeze the water out by running fingers along the length of the plaster three times. Laminate the plaster by running the palm over the plaster on a flat surface. Lay the plaster onto the padding, and fold the padding over the edges of the plaster (see the video below).

Posterior long arm splinting. Preparing and applying splint.

Apply the splint to the patient in the desired position. In the application of the splint, positioning depends on the injury. Typically, the posterior long arm splint maintains 90° of flexion at the elbow with neutral forearm and wrist positioning. The elbow, however, may be immobilized between 45° and 90°; the forearm may also be pronated or supinated, and the wrist may be flexed or extended.

A biomechanical study by Thompson et al found that the addition of one or two side struts to a long arm plaster splint significantly increased the load to failure and that a plaster cast with two side struts was comparable in strength to a half-fiberglass long arm cast.[12]

Once the splint is in position, secure it with an elastic bandage. The splint is permanently molded within 10 minutes. Recheck the patient’s neurovascular status. Place the patient’s arm in a sling.

Postprocedural Care

Provide appropriate discharge and follow-up instructions. These include instructions on resting, icing, and elevating the injured extremity and on keeping the splint clean and dry. If the patient received any sedation or opioids, advise against driving or alcohol consumption. Arrange timely follow-up in 1-5 days. Provide appropriate pain medication. If itching develops, consider prescribing an antihistamine (eg, diphenhydramine). If the itching persists or worsens, evaluate the splint for complications.


Complications of posterior long arm splinting include the following:

  • Thermal burns [13, 14] - Plaster hardens through an exothermic reaction, in which the amount of heat liberated is directly proportional to the setting process, which is based on the water temperature at which the splint is prepared; this reaction can cause burns if extremely hot water is used or if a barrier layer is not placed between the plaster and the patient’s skin
  • Pressure injuries [13, 15, 16] - This complication can be minimized by applying extra (thin) layers of padding at bony prominences
  • Contact dermatitis [13] - This complication can be minimized by ensuring full coverage of a clean dry extremity with the stockinette and providing adequate padding between the patient’s skin and the splinting material
  • Neurovascular compromise [13] – This complication can be minimized by documenting an intact neurovascular examination both before and after splinting; the patient should be reminded to seek immediate medical attention if he or she notices any decline in function or sensation of the extremity
  • Decreased range of motion - This complication can be minimized by encouraging timely orthopedic follow-up to prevent joint fusion


Medication Summary

The goals of pharmacotherapy are to reduce morbidity and prevent complications. Drugs used for injuries include various NSAIDs and analgesics. The strength of the analgesics depends on the type of pain resulting from the injury.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Class Summary

NSAIDs are the drugs of choice for the initial treatment of myofascial pain.

Ibuprofen (Motrin, Advil, Neoprofen, Ultraprin)

Ibuprofen inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis. It is used to provide relief of cervical myofascial pain.

Indomethacin (Indocin)

Indomethacin is thought to be the most effective NSAID for the treatment of ankylosing spondylitis, although no scientific evidence supports this claim. It is used for relief of mild to moderate pain; it inhibits inflammatory reactions and pain by decreasing the activity of COX, which results in a decrease of prostaglandin synthesis.

Naproxen (Naprosyn, Naprelan, Aleve, Anaprox)

Naproxen is used for relief of mild to moderate pain; it inhibits inflammatory reactions and pain by decreasing the activity of COX, which results in a decrease of prostaglandin synthesis.

Diclofenac (Voltaren, Cataflam XR, Zipsor, Cambia)

Diclofenac inhibits prostaglandin synthesis by decreasing COX activity, which, in turn, decreases formation of prostaglandin precursors.


Ketoprofen is used for relief of mild to moderate pain and inflammation. Small dosages are indicated initially in small patients, elderly patients, and patients with renal or liver disease. Doses higher than 75 mg do not increase the therapeutic effects. Administer high doses with caution, and closely observe the patient's response.

Opioid Analgesics

Class Summary

These medications provide control of moderate to severe pain.

Hydrocodone and acetaminophen (Vicodin, Lorcet, Lortab, Norco, Zolvit)

This drug combination is indicated for moderate to severe pain.

Acetaminophen with codeine (Tylenol-3)

This drug combination is indicated for mild to moderate pain.

Oxycodone and acetaminophen (Percocet, Endocet, Tylox)

This drug combination is indicated for the relief of moderately severe to severe pain. It is the agent of choice for aspirin-hypersensitive patients. Different strengths are available.

Oxycodone and aspirin (Percodan, Endodan)

This drug combination is indicated for the relief of moderately severe to severe pain.


Class Summary

Antihistamines generally work well for pruritus. The first-generation H1 antagonists (eg, diphenhydramine, hydroxyzine, doxepin, chlorpheniramine, cyproheptadine) are inexpensive and effective in reducing pruritus, but drowsiness and anticholinergic effects can be troublesome. The second-generation antihistamines (loratadine, desloratadine, fexofenadine, cetirizine, and levocetirizine) have much lower sedative effects. Any patient who is taking a medication that has potential sedative effects should be cautioned about driving and operating heavy machinery.

Fexofenadine (Allegra)

Fexofenadine is a nonsedating second-generation antihistamine. It is tolerated very well, with a rate of sedation that is not significantly different from that of placebo.

Cetirizine (Zyrtec)

Cetirizine selectively inhibits histamine H1 receptor sites in blood vessels, the gastrointestinal (GI) tract, and the respiratory tract, thereby inhibiting physiologic effects that histamine normally induces at H1 receptor sites. Once-daily dosing is convenient. Bedtime dosing may be useful if sedation is a problem.

Diphenhydramine (Benadryl, Altaryl, Anti-Hist, Diphenhist)

Diphenhydramine is used for symptomatic relief of symptoms caused by release of histamine. It is the most commonly used first-generation antihistamine, available without a prescription in the United States.

Hydroxyzine hydrochloride (Vistaril)

Hydroxyzine hydrochloride antagonizes H1 receptors in the periphery. It may suppress histamine activity in the subcortical region of the central nervous system (CNS).

Loratadine (Claritin, Alavert, Tavist ND Allergy)

Loratadine selectively inhibits peripheral histamine H1 receptors. It is tolerated very well, with a rate of sedation that is not significantly different from that of placebo. The once-daily dosing makes it convenient.

Desloratadine (Clarinex)

Desloratadine is a long-acting tricyclic histamine antagonist that is selective for H1 receptors. It is a major metabolite of loratadine, which, after ingestion, is extensively metabolized to the active metabolite 3-hydroxydesloratadine.

Levocetirizine (Xyzal)

Levocetirizine is an H1-receptor antagonist, an active enantiomer of cetirizine. It is a second-generation prescription antihistamine, available as a 5-mg breakable (scored) tab and a 0.5-mg/mL oral solution.

Chlorpheniramine (Ahist, Aller-Chlor, Chlor-Trimeton, Teldrin HBP)

Chlorpheniramine is a first-generation agent that competes with histamine for H1-receptor sites on effector cells in blood vessels and the respiratory tract. It is one of the safest antihistamines to use during pregnancy.

Cyproheptadine (Periactin)

Cyproheptadine is a first-generation agent used for symptomatic relief of allergic symptoms caused by histamine release. It prevents histamine release in blood vessels and is more effective in preventing histamine response than in reversing it. It may be useful in patients with syndromes sustained by histamine-producing tumors.