The shoulder is an incredible joint. It’s capable of extreme ranges of motion that allow you to throw a ball, swing a bat or push off against an opponent with extreme force. But it’s also one of the most vulnerable joints in the body. It’s a common targets for tackles and bodychecks, and it’s one of the first areas of the body that hits the ground during a fall.

This makes the joint susceptible to shoulder separations. In fact, 50 percent of shoulder injuries in contact sports are separated shoulders, which, depending on the severity of the injury, can keep an athlete out of action for up to 12 weeks.

To learn more about this common injury, we spoke with Dr. Ricardo E. Colberg, a non-surgical orthopaedic physician and sports medicine doctor at the world renowned Andrews Sports Medicine and Orthopaedic Center.

What is a Separated Shoulder?

A separated shoulder refers to an injury to the ligaments of the acromioclavicular joint (commonly known as the AC joint), which is the joint between the end of your collarbone and the upper part of your shoulder blade. This forms a major structural component of the shoulder.

The joint is supported by three ligaments, the acromioclavicular, conoid and trapezoid; however, the coracoclavicular ligament also acts on the joint and is often injured in more severe AC joint separations. Together, these ligaments allow the the arm to raise overhead and keep the collarbone aligned with the shoulder joint.

To locate your AC joint, place your hand on your collarbone and follow it toward your shoulder until your feel a small bump as it curves inward.

Technically, a separated shoulder should be referred to as an AC joint sprain or AC joint separation. But according to Colberg, “separated shoulder” became the widely used term for the injury, probably because the collarbone appears to literally separate from the shoulder.

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Colberg explains most injuries to the AC joint occur during some type of hard fall or contact, such as a football player diving for a touchdown, a cyclist falling and landing on his shoulder or even from a car accident. Another common cause is falling with an outstretched arm.

“Most of the injuries to this joint require a pretty high force transmitted to the side and top part of the shoulder,” Colberg says. “That joint has the joint capsule and has three ligaments around it, so it’s a fairly sturdy joint. In order to rupture those ligaments, you have to take a fairly significant blow.”

AC joint injuries are categorized into six grades ranked in increasing severity:

• Grade 1 – The ligaments are pulled but there’s no tearing.

• Grade 2 – The AC ligament tears, leading to a partial separation.

• Grade 3 – The AC ligament and other associated ligaments tear, leading to a complete separation.

• Grades 4-6 – These are complete separations, but the grade number depends on where the collarbone is located after the separation. Sometimes it shoots straight up making a large bump in the skin. Other times, it pierces backward and gets jammed in the trapezius muscle or moves straight down and gets stuck on the shoulder blade.

After an injury, there will be significant pain in the location of the AC joint along with limited range of motion, weakness and instability. If the injury is a Grade 2 or above, you may actually be able to see the collarbone sticking up under the skin. The worse the injury, the more pronounced this will be.

Colberg says there are two common tests used to identify an AC joint injury.

Cross Arm Test: Bring your arm up to 90 degrees and reach across and touch your opposite shoulder. You will feel significant pain if there’s an injury.

Piano Key Sign: You can actually move the collarbone if there’s an injury. Simply press it down and it will pop back up like a piano key.

Generally with a separation of Grade 2 or above, there will be a lot of pain and you will have difficulty elevating your arm.

However, because the symptoms are similar, AC joint injuries are often confused with rotator cuff injuries. This highlights the importance of seeing to a doctor and not self-diagnosing if you suspect a shoulder injury.

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“We do recommend getting evaluated by a sports medicine trained physician,” advises Colberg. “It’s hard to distinguish whether there was an injury to the rotator cuff tendons or to the AC joint.”

Separated Shoulder Treatment and Rehab

The severity of the injury determines the complexity of the treatment. Fortunately, all but the most severe AC joint injuries require non-surgical treatment, so you won’t be out of your sport for a significant duration.

Grade 1: You can return to play within a week or two after you’re pain-free, have full range of motion and full strength. Treatment includes rest and anti-inflammatory medication.

Grades 2 and 3: A Grade 2 injury takes about 3-4 weeks to fully heal, and a grade 3 injury takes up to eight weeks to heal. No surgery is required; however range of motion is restricted.

Grades 4-6: The joint has to be surgically repaired. The method used depends on the surgeon, but it typically involves tying the collarbone back into the proper position and sometimes reconstructing the damaged ligaments. Also, other damaged shoulder tissues likely need repair. The typical recovery time is 12 weeks.

It’s important to see a doctor as soon as possible after a suspected injury. “If you do the surgery early, it has a better chance of healing well,” says Colberg. “If you do them after say six weeks, there’s a higher chance of residual instability or it may even tear again.”

With the exception of Grade 1 injuries, it’s advisable to see a physical therapist to restore strength and range of motion. For Grades 2 and 3, physical therapy usually begins after the first week with exercises such as Side Elevations and Pendulum Swings before progressing to resistance band exercises. For overhead athletes, light throwing is recommended between weeks three and four.

For Grades 4-6, therapy is more intensive. The shoulder is immobilized for a few weeks before physical therapy begins with extremely light exercises to gradually restore strength and range of motion in the joint.

How to Prevent a Separated Shoulder From Occurring

AC joint injuries are the result of contact, so it’s impossible to completely prevent them. It’s a potential risk when playing a sport with contact, or even tripping and falling.

Proper padding protects the region from impact. And, building muscle around the shoulder can add extra support and durability. But again, injuries can still happen.

To make falls less damaging, Colberg recommends taking a page from martial artists.

“The only way to try to prevent an injury is to learn to roll when you’re falling,” he explains. “In martial arts, they teach when you’re going down to roll so you bring your shoulder in and your head down and you take your impact more on your scapula, and then you roll forward and dissipate the energy of the fall.” This move is often referred to as “tuck and roll.”

If you’ve already suffered an ACL joint injury, you need to be extra careful to avoid re-injuring the area. After physical therapy, it’s important to build your strength back up in the weight room so you have the necessary strength and size to compete in your sport. And, of course, it’s always best to take your time coming back to your sport despite all your temptations to rush.

“The most often mistake that leads to re-injury is return to play too soon,” Colberg says. “Ligaments need at least two weeks to scar down and heal. We see it all the time in football players.”

Once you do return, you can better protect the area by adding extra memory foam padding to the underside of your shoulder pad.

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