Ricardo E. Colberg, M.D.
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 body checks, 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, STACK spoke with Dr. Ricardo E. Colberg, a non-surgical orthopaedic physician and sports medicine doctor at the world renowned Andrews Sports Medicine & 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.
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...