A sling is a supportive device intended to immobilize and hold an injured arm, wrist, or hand close to the body. This immobilization helps to reduce movement, decrease pain, and protect the injury from further damage while awaiting professional medical care. The most common material is a triangular bandage, often included in first aid kits. A large square of non-stretchy cloth, such as from a bedsheet, can be used as an improvised alternative. The goal of this support is to suspend the weight of the limb from the neck and shoulder, shifting the load away from the injured site.
Preparing the Materials and Positioning the Patient
To begin, you will need a triangular bandage or a piece of cloth measuring approximately 40 inches on each side, folded diagonally to form a large triangle if improvising. Have safety pins or medical tape available for securing the sling later. Remove any jewelry, such as rings or watches, from the injured arm to prevent circulation issues if swelling occurs. The person should sit upright, and the injured arm must be gently placed across their chest, supported by the uninjured arm during positioning.
The forearm should be bent so the elbow is at roughly a 90-degree angle, which is the optimal position for stabilization and comfort. This bend ensures the limb is resting in a neutral position that minimizes muscle strain and joint stress. Drape the triangular bandage over the person’s chest. The longest edge (the base) runs parallel to their body, with one sharp corner (the apex) pointing toward the elbow of the injured arm.
Creating the Basic Triangular Arm Sling
With the injured arm supported at the 90-degree angle across the chest, position the base of the triangular bandage so that the midpoint is directly under the injured forearm. Bring one end of the bandage, situated near the uninjured shoulder, up and over the shoulder and then drape it behind the neck. Bring the other free end, hanging down over the injured arm, upward, over the injured shoulder, and across the back to meet the first end.
The two ends of the bandage should meet at the side of the neck, resting over the collarbone on the uninjured side, rather than directly on the sensitive cervical spine. Secure the two ends together using a square knot, which is preferred because it is flat and secure. If possible, place padding, such as a folded cloth, under the knot on the neck to increase comfort and prevent irritation. Adjust the sling before the knot is fully tightened so that the hand is slightly elevated above the level of the elbow, which helps to encourage blood return and reduce potential swelling.
Securing the Sling and Checking for Safety
Once the square knot is tied, the apex of the triangle, which extends past the elbow, must be secured to create a snug pocket for the limb. Twist the excess material at the apex until it fits firmly around the elbow; this twist can then be tucked into the sling or secured with a safety pin or tape. This prevents the elbow from slipping out of the sling and maintains the proper arm position. The front edge of the sling should extend all the way to the base of the little finger, ensuring the entire forearm and wrist are fully supported.
After the sling is secured, a systematic check for proper circulation in the injured limb is necessary. The fingers should be exposed so you can check their color, warmth, and sensation. If the person reports tingling, numbness, or if the skin appears pale or blue, the sling is too tight and must be immediately loosened and readjusted. A quick capillary refill test can be performed by pressing on a fingernail for five seconds; the color should return to the nail bed within two seconds after the pressure is released. This monitoring must be repeated every ten minutes to ensure the sling continues to function safely.