An arm sling holds your injured arm against your chest, keeping the elbow bent at a right angle and the hand positioned higher than the elbow. You can make one with a standard triangular bandage from a first-aid kit or improvise with common household items like a shirt, belt, necktie, or bedsheet. The technique takes about two minutes once you know the steps.
What You Need
A standard triangular bandage measures roughly 102 x 102 x 142 cm (about 40 x 40 x 56 inches). Most first-aid kits include one. If you don’t have a triangular bandage, you can cut any large piece of fabric diagonally to create a triangle, or skip the triangle entirely and use an improvised method (covered below).
You’ll also want a safety pin to secure the elbow corner and some soft padding material for the neck, even a folded washcloth or sock.
Standard Sling: Step by Step
Have the injured person sit or stand comfortably. Bend their elbow to a 90-degree angle so the forearm is level across the stomach.
Hold the triangular bandage so one point hangs straight down. Place the top point of the triangle behind the elbow of the injured arm. Lay the longest edge of the bandage along the person’s body so that the wrist sits midway along the bottom edge. The fabric should drape across the chest and under the forearm.
Now bring the two free points of the triangle up: one goes around the front of the neck and the other goes around the back, both meeting on the same side. Tie them together at the side of the neck, not directly over the spine. This is important because a knot sitting on the back of the neck creates a painful pressure point. Pad the knot with a folded cloth for comfort.
At the elbow, gather the loose fabric and fold it neatly, then secure it with a safety pin to form a snug pocket. Tuck or trim any excess material so nothing hangs loose.
Getting the Position Right
Three things tell you the sling is correct. First, the hand should sit slightly higher than the elbow. This positioning helps reduce swelling by encouraging fluid to drain away from the fingers and wrist. Second, the elbow should be bent at a right angle, roughly 90 degrees. Third, the fingertips should be visible and exposed so you can check them.
The arm should rest comfortably against the chest without pulling to one side. If the person feels like the arm is sagging or the sling is cutting into the neck, the knot position or fabric length needs adjusting.
High Elevation Sling
A high sling raises the hand above shoulder level and is used when you need extra elevation, typically for hand or wrist injuries where swelling is a major concern. The setup differs from a standard sling.
Place the injured hand on the opposite shoulder. Lay the triangular bandage diagonally across the chest, following the line from the shoulder down to the elbow of the injured arm. Tuck the lower edge of the bandage under the elbow, making sure the hand is fully enclosed in the fabric. Bring the bottom point around to the back and tie it to the top point behind the back or just below the shoulder of the injured arm. Secure the elbow corner with a safety pin to create a cradle.
Keeping the Arm Still With a Swathe
A sling alone allows some movement of the arm away from the body. For injuries that require full immobilization, like a shoulder dislocation or upper arm fracture, you can add a swathe. This is simply another strip of cloth wrapped around the chest and the sling together, then tied on the uninjured side. It pins the arm firmly against the torso and prevents it from swinging outward.
Improvising Without a Bandage
If you don’t have a triangular bandage, several everyday items work well:
- A button-up shirt or jacket: Pin the hem of the shirt up to the chest area to create a pouch, or slip the hand inside the buttoned front between two buttons at chest height.
- A belt or necktie: Loop it from the wrist, up and around the neck, and back to the wrist. Pad the neck where the material sits.
- A bedsheet or towel: Fold it diagonally to create a triangle and follow the standard sling steps above.
The goal with any improvised sling is the same: elbow at 90 degrees, hand higher than the elbow, arm resting against the chest.
Checking Circulation After Application
Once the sling is on, check three things at the fingertips: pulse, sensation, and movement. Squeeze a fingernail and watch for the color to return within two seconds. Ask the person if they can feel you touching their fingers. Have them wiggle their fingertips gently. If the fingers look pale, blue, or swollen, or if the person reports tingling or numbness, loosen the sling and readjust.
Repeat these checks periodically, especially in the first hour. Swelling can increase after an injury, and a sling that fit well initially can become too tight.
Common Mistakes to Avoid
The most frequent error is letting the hand hang lower than the elbow. This allows blood to pool in the fingers, increases swelling, and slows healing. Always double-check that the wrist is slightly elevated.
Placing the knot directly on the back of the neck is another common problem. Even with padding, a centered knot digs into the spine and becomes painful within hours. Tie it off to one side instead.
Wearing a sling too loosely lets the arm swing and bounce with movement, which can worsen pain and strain a healing injury. Wearing it too tightly restricts blood flow. The fabric should be snug enough to hold the arm steady but loose enough that you can slide a finger between the sling and the skin.
When Each Type of Sling Is Used
A standard sling works for forearm fractures, elbow injuries, and as a support after shoulder surgery. It holds the arm at a comfortable mid-chest position. For shoulder dislocations or upper arm fractures, a sling plus swathe combination provides the extra stability needed to prevent the joint from moving.
A high elevation sling is typically reserved for hand and wrist injuries where controlling swelling is the priority. Raising the hand above the heart lets gravity work in your favor. Your medical provider will tell you which type to use based on your specific injury, but knowing how to apply both is useful in a first-aid situation when you need to stabilize an arm before help arrives.