A standard shoulder sling holds your arm against your chest with the elbow bent at 90 degrees and the hand positioned slightly higher than the elbow. Getting it on correctly takes about a minute once you know the steps, but small mistakes in positioning can cause neck pain, poor circulation, or inadequate support for your injury. Here’s how to do it right.
How to Put On a Standard Envelope Sling
Most slings you’ll get from a hospital or pharmacy are envelope-style: a pouch of fabric with a long adjustable strap. Start by loosening the strap completely so you have room to work with.
- Slide your arm into the pouch. Place your elbow all the way into the back corner of the sling so it fits snugly. Your forearm should rest flat along the bottom of the fabric, with your hand coming out the open end near the wrist.
- Bring the strap behind your neck. Take the strap up and over the shoulder on your uninjured side, then loop it around the back of your neck to connect to the other side of the sling. The strap should cross the opposite shoulder from your injured arm, not the same one.
- Adjust the strap length. Tighten or loosen the strap until your elbow sits at a 90-degree angle, a perfect right angle. Your hand should be slightly higher than your elbow, roughly at the level of your chest. Your palm should face inward toward your body.
- Check your wrist position. Your wrist should be straight or angled very slightly upward (about 10 to 20 degrees of extension). If your wrist droops down over the edge of the sling, the pouch is too short or positioned too far back.
- Make sure your fingertips are exposed. The sling should not cover your fingers. You need to see them to monitor for color changes, and you need to move them regularly.
When the sling is positioned correctly, your arm rests comfortably against your chest without you needing to hold it in place. If you feel like you’re fighting the sling to keep your arm still, the strap length needs adjusting.
Putting It On by Yourself
Applying a sling one-handed is awkward but doable. The key is to set up the sling before you try to get your arm into it. Lay the sling flat on a table or your lap, fully open, with the strap loosened. Slide your injured arm into the pouch first, letting gravity help settle your elbow into the corner. Then use your free hand to grab the strap and pull it up and over your head, draping it across the opposite shoulder. From there, adjust the strap with your good hand until the height feels right.
If the strap has a buckle or Velcro closure, position it on your chest or near your collarbone rather than directly on the back of your neck. This makes it easier to reach with one hand and avoids the buckle digging into your skin.
Adding a Swathe for Extra Stability
Some injuries, especially fractures or post-surgical shoulders, need more immobilization than a sling alone provides. A swathe is simply an elastic bandage or wide strap wrapped horizontally around your body. It goes around the outside of the sling and around your torso, passing under your uninjured arm, to pin the sling tight against your chest. This prevents your arm from swinging outward when you walk or turn, which matters a lot in the first few weeks after surgery or a break.
Abduction Pillow Slings
If you’ve had rotator cuff surgery, your surgeon may give you a sling with a foam pillow or wedge that sits between your arm and your body. This is an abduction pillow sling, and it works differently from a standard sling. Instead of holding your arm flat against your chest, the pillow keeps your arm angled 30 to 45 degrees away from your body. That position reduces tension on the surgical repair.
These slings are typically applied right after surgery while you’re still in a reclined position. The pillow straps around your waist, and the arm cradle attaches separately. If you need to remove and reapply it at home (for showering or changing clothes), follow the specific instructions from your surgeon, because the angle matters. Putting your arm too close to your body defeats the purpose of the pillow.
Common Positioning Mistakes
The most frequent error is wearing the sling too low. When the strap is too long, your elbow drops below 90 degrees, your hand hangs near your hip, and the sling provides almost no support. Your shoulder muscles end up doing all the work, which increases pain. Shorten the strap until your forearm is parallel to the ground.
Another common problem is letting the strap sit directly on bare skin at the back of your neck. Over hours, this creates a pressure sore. Pad the strap with a folded washcloth, a piece of foam, or a small towel. Some slings come with a padded neck piece for this reason.
Tucking your fingers inside the sling is also a mistake. Your fingertips need to stay visible and free to move. Hidden fingers are fingers you can’t monitor for swelling or color changes, and they’ll stiffen quickly without movement.
Signs the Sling Is Too Tight
After putting on your sling, check your hand every few hours. Tingling, numbness, or weakness in your fingers means the sling is compressing a nerve or blood vessel. A hand that turns cold, pale, or bluish is losing circulation. Either problem calls for immediate loosening of the strap and repositioning. If the symptoms don’t resolve within a few minutes of adjustment, that needs medical attention the same day.
Keeping Your Hand and Wrist Limber
Wearing a sling for weeks can stiffen your fingers, wrist, and elbow surprisingly fast, even though those joints aren’t injured. Simple exercises prevent this, and you should do them frequently: about five minutes every waking hour.
Start by making a fist, then stretching your fingers wide, spreading them as far apart as you can. Repeat that 10 times, working up to 30 as it gets comfortable. Then bend your wrist up and down through its full comfortable range, again for 10 to 30 repetitions. These movements maintain circulation, reduce swelling, and keep the joints from locking up. You can do them with your arm still in the sling by simply freeing your hand from the pouch’s edge.
Your elbow also needs occasional gentle movement unless your doctor has told you otherwise. When you remove the sling for bathing or dressing, slowly straighten and re-bend the elbow a few times before putting the sling back on.