Installing an arm sling is a medical procedure in managing arm injuries that aim to immobilize the arm and reduce pain. In cases of trauma, the arm slings support bone unification and healing of injured soft tissue. Wearing arm slings can also help patients who have had chronic strokes to improve gait patterns and efficiency.

Arm Sling: Types, Indications, Complications, and How to Apply It Correctly

Technically, applying the conventional arm sling requires a cotton cloth in the isosceles triangle shape with a side length of 90 cm and a safety pin or medical tape. In contrast, a modern arm sling has been equipped with a neck belt and waist belt. The neck belt functions to immobilize the forearm against the upper arm, while the waist belt or shoulder immobilizer functions to immobilize the arm to the patient's body axis.

After wearing an arm sling, avoid worsening the injury by evaluating circulation, sensory, and motor. In principle, there are no specific complications associated with wearing arm slings despite a case report of pressure sores to the neck due to pressure from the arm sling neck belt.

There are several types of arm slings, namely:
  1. broad arm sling,
  2. high arm sling,
  3. poly arm sling (polysling),
  4. collar and cuff sling

Clinical Guidelines

Clinical guidelines that need to be considered in installing arm slings include:
  • Types of arm slings commonly used are broad arm slings, high arm slings, poly arm sling with a waist belt (shoulder immobilizer), and the collars and cuffs sling.
  • The Broad arm sling is useful to immobilize forearm fractures, clavicle fractures without bone displacement, acromioclavicular ligament tears, and simple elbow injuries.
  • The high arm sling is useful for post-injury swelling of the arm or hand with or without active bleeding. It also immobilizes the arm in the pseudoparalysis case due to clavicle fracture.
  • The poly arm sling is a modern modification of the broad arm sling, which improves walking patterns and post-stroke patient endurance when walking. A poly arm sling equipped with a waist belt is referred to as a shoulder immobilizer and is used after reducing shoulder dislocations, rotator cuff tears, and acromioclavicular dislocations.
  • Applying an arm sling has no special contraindications. However, every doctor still needs to be aware of possible complications such as cervical injuries, causing technical limitations when installing an arm sling.
  • After wearing the arm sling on, educate the patient sufficiently on assessing circulation, sensory and motor function in the distal area, and duration of wearing the sling. Also, provide education about how to take and the potential side effects of analgesics.

Steps How To Put on Arm Sling Correctly

The arm sling installment procedure can be performed by one or two medical personnel using a triangular bandage or a commercial arm sling equipped with a neck and waist belt (poly arm sling). In principle, the arm sling installment aims to immobilize the forearm, upper arm, or shoulder joint as indicated.

1. Preparation

Preparation for an arm sling installment is the same as the evaluation steps performed on all injured patients. The primary survey is performed according to the recommended Advanced Trauma Life Support (ATLS) guidelines. A secondary survey can be carried out after the primary survey and concentrated on finding a more specific injury diagnosis.

Regarding an arm sling indication, do inspection directly at the clavicle, shoulder joint, upper arm, forearm, and hand. Things that need to be considered during an inspection are skin discoloration, edema, hematoma, wounds, and deformities. Then, ask if the patient can move the limb normally. Palpate the extremities to test sensory function or identify pain or crepitus from the fracture.

The radiological examination is performed to confirm the diagnosis. Arm slings can be useful to help mobilize and reduce pain before and after X-rays.

2. Equipment

Equipment required to put on an arm sling includes a triangular bandage or cotton cloth in the shape of an isosceles triangle, each leg about 90 cm long, safety pins or medical tape, or a commercial arm sling with a neck and waist belt (for example, for a poly arm sling attachment). To put on the collar and cuff arm sling require a long foam, rope or plastic to tie, and scissors.

3. Position of the Patient

When installing the arm sling, ensure the patient is sitting upright with the injured arm in a relaxed position and the hand horizontally across the abdomen to the contralateral side. If the patient cannot sit upright due to an injury elsewhere, attach an arm sling with ensuring optimal immobilization while the patient is lying down.

4. Procedure

The procedural technique of how to put on an arm sling varies depending on the type used. In this section, the arm sling installation technique is distinguished for broad arm slings, high arm slings, shoulder immobilizers, the collar and cuff arm slings.

a. Broad Arm Sling
  • Place the patient's injured arm with the shoulder relaxed. Put the hand across the abdomen to the opposite side of the arm. The hand is higher than the elbow of the injured arm.
  • Extend the sling between the forearm and chest so that its longest side is perpendicular to the injured arm and its greatest angle is near the injured elbow. The other two corners of the sling will be on the shoulder and thigh on the injured arm's contralateral side.
  • Fold the sling corner near the thigh over the injured arm until it reaches the shoulder on the same side as the arm.
  • Firmly tie both corners of the sling at the shoulder level comfortably behind the patient's neck.
  • Fold the sling corner near the injured arm's elbow forward to secure the elbow from movement and then attach the angle to the sling material using a pin or tape.

b. High Arm Sling
  • Place the patient's injured hand at the level of the contralateral shoulder.
  • Extend the sling over the injured chest and arm so that its greatest angle is in the middle of the upper arm from the injured side. The other two corners of the sling will be on the contralateral shoulder and the ipsilateral thigh from the injured arm's side.
  • Fold the sling's long side under the injured arm and make sure that the sling covers the injured hand.
  • Gently pull the corner of the sling near the thigh towards the patient's back.
  • Tie the corner of the sling on the lower back to the sling corner near the contralateral shoulder. The knot can be between the shoulder blades or under the injured shoulder.
  • Secure the corner of the sling that is still free to the back of the sling material using a pin or tape to secure the injured elbow.

c. Shoulder Immobilizer (poly arm sling)
  • Place the sling and shoulder belt on your forearm and pull tightly around the elbow.
  • Adjust the sling length by folding the ends of the sling material inward to achieve the desired length.
  • Close the sling's end on the hand by attaching the D-ring belt and ring's position in the middle of the belt on the top of the arm, while the second ring is facing the patient.
  • Close the sling tightly by gluing the belt cover at the elbow.
  • Support the arms by connecting the shoulder belt over the shoulders and around the patient's back.
  • Insert the shoulder belt into the top of the D-ring. Adjust the length of the shoulder belt so that the patient is comfortable, then fix it.
  • Place an immobilization belt around the injured elbow and insert it into the D-ring near the patient's wrist to ensure that the shoulder is fixed.

d. Collar and Cuff Sling
  • Place the soft part behind the patient's neck.
  • Make knots above and below the injured arm.
  • Check that the knot is firm enough to keep your hand from shifting. When the patient is standing, the arm will be shaped like an "L" (90-degree angle).
  • If the arm sling loosens or shifts, then position it again so that it is secure.

Complications of Arm Sling Installment

The frequency and types of complications associated with wearing arm sling procedures have not been studied systematically. In a case report by Radha et al., the use of poly arm sling for four weeks was associated with the incidence of decubitus sores in the neck area where the poly arm sling belt rests. These sores can even appear in patients who do not have the factors that increase pressure sores' risk. However, these decubitus wounds' complications were improved thanks to adjustment of the poly arm sling belt looseness and installation of additional cushioning between the wound and belt, and simple wound care by the nurse.

One preventive measure that can identify patients at high risk of such pressure sores is to assess the Braden score prior to poly arm sling. However, the Braden score has never been validated to predict the risk of pressure sores from poly arm sling or other types of arm slings, and a threshold score separating high and low-risk patients have not universally been established.