Wilderness Medical Series — Module 10

Stabilizing Lower Extremity Injuries With Improvised Splints

How to stabilize lower extremity injuries with improvised splints when a SAM splint is unavailable — principles, materials, and field techniques.

By Joshua Enyart · Founder & Head Instructor, Gray Bearded Green Beret

Former Army Ranger, Green Beret, and full-time survival instructor · three decades of professional instructor experience

The SAM® splint is the right tool for field splinting. Carry two in every wilderness medical kit. But the SAM® splint may not be there — it was left behind, it has been used on a previous injury in the group, or the injury happened in a setting where the full kit was not accessible.

Improvised splinting from available materials is a genuine wilderness medicine skill. It is not the preferred technique — purpose-built splinting material is more reliable and faster to apply — but it is a capable backup when the purpose-built option is genuinely unavailable. This article covers the full principles of improvised splinting and the specific construction techniques for lower extremity injuries.

What Makes an Improvised Splint Work: The Seven Principles

An improvised splint that works is not improvised loosely. It applies the same seven splinting principles that govern commercial splint application — the material is different, but the framework is identical.

• Manually stabilize first: Hold the injury with your hands before construction begins. Immobilize the injury at the site — do not move the affected limb unnecessarily during the build.
• Position of function: The splint captures the extremity in its neutral anatomical position. For the ankle, this is 90 degrees between foot and lower leg. For the knee, this is slight flexion (approximately 10–15 degrees). Forcing an injured joint into a non-neutral position causes additional injury and pain.
• Accessible for CMS: The improvised splint must be built in a way that allows circulation, motor, and sensation checks at the distal extremity (toes, foot) before and after application without removing the entire splint.
• Padded at pressure points: Wherever rigid material contacts a bony prominence — ankle malleolus, heel, tibia crest — add padding. Clothing, a bandana, foam from a sleeping pad, or rolled fabric between the rigid material and the skin prevents pressure injury during extended wear.
• Rigid: The material must provide real rigidity — resistance to bending under the patient's load. Flexible material that bends when weight is applied provides no stabilization. Straight sticks, tent poles, trekking pole sections, and rolled foam pads are common wilderness materials that achieve functional rigidity.
• Adjustable: Fasten with knots or wraps that can be released quickly. CMS changes require immediate splint adjustment. A knot that requires ten minutes to release under stress is a liability.
• Secure above and below the joint: The rigid material and securing elements must capture both the joint above and the joint below the injury. For an ankle fracture, the splint extends from the foot to the lower leg. For a lower leg fracture, from the foot through the knee.

Sourcing Rigid Material in the Field

Rigidity is the primary property required from improvised splint material. Almost any material that does not bend under the load of the extremity will function. The field provides multiple options.

Straight sticks: The most widely available improvised rigid material in any wooded or brushy terrain. Sticks must be straight, smooth (no sharp protrusions or bark ridges that create pressure points), and long enough to extend above and below the injury site. Select two sticks — one for the medial aspect and one for the lateral — for an ankle or lower leg splint.

Trekking pole sections: A collapsed trekking pole provides a rigid, smooth-surfaced splint component with adjustable length. Two poles placed medially and laterally alongside a lower leg fracture provide excellent rigidity. Remove the basket and tip to prevent additional skin irritation from the ends.

Tent poles: Similar to trekking poles in diameter and rigidity. Aluminum tent poles can be configured to length for specific injury sites.

Rolled sleeping pad: A tightly rolled closed-cell foam sleeping pad provides padded rigidity. The closed-cell foam structure — unlike an inflatable pad — maintains its rolled shape and provides a cushioned contact surface that reduces pressure point concerns.

Sourcing Securing Material in the Field

Securing material holds the rigid components in place and provides the compression element. Improvised securing material is even more widely available than rigid material.

Cravats and bandanas: If any are present in the kit or on the group's gear, they are the first-choice securing material. Purpose-built for body wrapping applications.

Torn fabric strips: Any clothing that can be cut or torn into strips provides securing material. Cotton tears reasonably cleanly along the weave. Strips 2–3 inches wide provide workable cravats.

Paracord: Ubiquitous in wilderness kits. Provides strong, thin securing material. Paracord must be padded at the knot points and on any bony prominences — its narrow profile concentrates pressure more than cravats. Use it as a lacing material over wider fabric backing rather than directly on skin where possible.

Pack straps and webbing: Load-bearing straps from a backpack can be removed and used as securing material. The straps on external frame packs and internal frame packs are typically wide enough to distribute pressure appropriately.

Constructing a Lower Extremity Improvised Splint

The following procedure applies to improvised lower extremity splinting — ankle, lower leg, or combined ankle-to-knee applications:

• Check CMS before construction. Capillary refill at toes, toe movement, sensation in foot.
• Manually stabilize the injury with one hand or have a second person hold the extremity while you construct.
• Pad bony prominences: ankle malleolus (inside and outside), heel, shin crest. Clothing, bandana material, or sleeping pad foam between rigid material and skin.
• Position the rigid material: place two sticks, poles, or trekking sections alongside the extremity — one medial, one lateral — extending from the foot to the lower leg (or from the foot through the knee for higher injuries). The material should extend a few inches beyond each joint it is intended to capture.
• Secure at the foot: wrap first at the most distal point. Snug but not tight — two fingers should pass under the wrap.
• Secure at the ankle: wrap above and below the malleoli, capturing the rigid material against the medial and lateral aspects of the ankle.
• Secure at the lower leg: one to two additional wraps between the ankle and the knee, depending on the injury location.
• Recheck CMS. Any change from baseline — numbness, tingling, cold toes, absent capillary refill — requires immediate splint adjustment.

The Difference Between Stabilization and Immobilization

In a field context, 'stabilized' and 'immobilized' are not the same thing. A stabilized fracture is protected from the movements that cause the most harm — rotation, angulation, telescoping of the bone ends. An immobilized fracture has been taken entirely out of motion.

Improvised splints typically achieve stabilization, not complete immobilization. A stick-and-cravat ankle splint applied correctly limits harmful motion enough for careful evacuation. It does not produce the zero-motion immobilization of a vacuum splint or a well-formed commercial moldable splint.

That is acceptable in the field. The goal is not perfect immobilization — it is stable enough for evacuation. A stabilized fracture that can be carefully carried or walked with assistance is a manageable field problem. An unstabilized fracture being moved over rough terrain is not.

Movement After Improvised Splinting

After an improvised splint is applied, assess whether the patient can be moved and how. The movement plan depends on the injury type, the terrain, and the available resources.

A stabilized ankle fracture with an improvised splint may permit non-weight-bearing movement — being supported between two people or using a makeshift crutch — for limited distances over reasonable terrain. Weight-bearing on a fractured ankle is not recommended, but careful non-weight-bearing movement may be possible.

A stabilized lower leg or knee fracture requires more support and is typically not a self-rescue situation. Signal for evacuation, prepare a comfortable position for the patient, and reassess CMS every thirty minutes while waiting. If conditions require movement — weather deterioration, rising water, proximity to hazard — move the patient in the most controlled manner possible: carried between multiple people with the injured extremity supported.

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