Athletic Injuries 101: Separated Shoulder

Separated-ShoulderIn this edition of Athletic Injuries 101, Dr. Sarah Ytsma explains the separated shoulder, including an explanation, causes, and treatment of a separated shoulder.


The “AC” joint is anatomically known as the ACROMIOCLAVICULAR joint, or the joint that forms on the top part of the shoulder between the acromion, a portion of the scapula or shoulder blade, and distal portion of the clavicle or the collar bone. When someone injuries this joint it is commonly referred to as a SEPARATED SHOULDER.


Typically, the most common way to injure the AC joint is through direct trauma on the joint such as getting checked into the boards during hockey or falling directly on the shoulder during football, skiing, snowboarding, etc. Occasionally, the AC joint can become problematic if the anatomy of the acromion differs from the norm.


Type 1: flat acromion is just as it says, flat along the bottom.
Type 2: curved acromion has a slight rounded appearance and is the most common type.
Type 3: also known as a hooked acromion, this can easily lead to rotator cuff impingement syndromes with overuse of the shoulder, improper weight lifting techniques, and poor postural syndromes. The hooked portion at the tip of the acromion creates less room for the supraspinatus tendon that runs through the glenohumeral joint, creating possible impingement at the shoulder. These are often candidates for surgery as chronic impingement at this area will often lead to a rotator cuff tear.



AC Ligament

CC Ligament

Joint Capsule


Collar Bone

I Sprained Normal Normal Normal Normal
II Ruptured Sprained Ruptured Slightly detached Higher than normal but not above the acromion
III Ruptured Ruptured Ruptured Detached Higher than acromion
IV Ruptured Ruptured Ruptured Detached Displaced backwards
V Ruptured Ruptured Ruptured Detached  
VI Ruptured Ruptured Ruptured Detached Displaced through bicep and coracobrachialis muscles



Type’s V and VI are very rare to happen. Surgery is required for types III – VI to repair the ligaments. Extensive rehabilitation is required after surgery. Type I and II separation can be helped significantly with rehab. Ice, rest, and support of the arm are required after immediate injury. Range of motion and strength must be restored after initial pain and swelling have subsided.

Dr. Sarah Ytsma provides traditional chiropractic care, soft tissue manipulation/mobilation, and clinical acupuncture treatments at her office locations in Chatham (463 St. Clair Street @ Activaid – 519.358.7342) and Blenheim (110 Talbot Street @ McLauchlin Wellness – 519.676.3311 ext.1). Dr. Ytsma believes in stabilization and rehabilitation of injured joints to get you functioning and back on your feet, or in the game. For more visit

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