AC Joint Sprain(Acromial Clavicular)
The acromioclavicular joint (AKA AC joint) is the joint between the clavicle and shoulder blade. The joint is held up by four ligaments (superior, inferior, anterior, and posterior AC ligaments) which protect the clavicle from excessive movement in any direction. AC joint sprains come from a fall or trauma, like a lift gone wrong. If you have sprained this joint it will limit how stable you feel in your shoulder and you will often notice pain with specific movements. AC joint injuries are graded on a scale:
- Grade 1: mild, unseparated sprain of the AC ligaments with no disruption of the coracoclavicular ligaments.
- Grade 2- complete disruption of the AC ligaments with joint separation (less than 4 mm or 40% difference) and sprained but intact coracoclavicular ligaments.
- Grade 3- complete disruption of AC and coracoclavicular ligaments with joint separation and inferior displacement of the shoulder complex.
How does an AC sprain happen?
AC sprains most commonly occur following a fall onto the top of the shoulder with the arm close to your side (adducted) (2). This force on the outside of the arm causes the acromion to separate from the clavicle. We see it most commonly with seat belt injuries during a car accident and in contact sports when a player lands on an outstretched arm. AC joint injuries are responsible for 40-50% of all athletic shoulder injuries (3).
Do you have an AC joint sprain?
- The classic presentation involves pain and swelling on the top of the shoulder following a recent trauma. Pain, swelling, and/or bruising initially is over the entire shoulder region, but as swelling decreases, it becomes more localized to the AC joint region.
- Specific movements cause pain & limited shoulder mobility
- Rolling on the side in bed is aggravating
- Pinpoint tenderness over the AC joint
- Bulge in the shoulder
- Elevated clavicle
Do you need imaging for an AC joint sprain?
In most cases of sprains and strains, you will not need additional imaging. X-rays rule out fracture and that can also be accomplished through a thorough examination of the injury in most cases. During your consultation and examination, your chiropractor will evaluate the injury and determine if imaging is appropriate for you. In some cases, MRI can be a useful tool to determine if there is a need for surgical repair but in nearly all cases surgery is considered not necessary for recovery.
How can a chiropractor help with an AC joint sprain?
A conservative approach is typically the primary method used for managing Grade I & II AC joint sprains (5). The initial phases of injury include the PEACE & LOVE approach to soft tissue injury. This is where we rest the joint and give it some time to heal, to try to decrease pain & inflammation. Everyone responds a little differently to this kind of trauma. The goal is safe and painless movement as quickly as possible to aid in recovery. The middle phase of care typically involves mobilization and gentle adjustments (if needed). This phase starts the strengthening process and gets you on the road to recovery. Our approach to treating an AC joint sprain depends on where you’re at in the healing or rehab process.
Treating an AC joint sprain in the first 2 weeks:
- Deep Tissue Laser Therapy– This is a great tool we have to help with the initial phase of healing when it comes to decreasing pain & inflammation, as well as speeding up your healing process
- Dynamic Tape-Using supportive taping we can assist your ranges of motion and give the tissues a break from their normal activity without overly restricting your mobility.
Middle Phase of Injury:
- Mobilizations and Adjustments-These techniques allow your chiropractor to help the joint return to its normal positions and improve its natural pain-free range of motion. All hands-on techniques during this phase are dependent on pain and it helps us determine when you are ready for this therapy.
- Light weight resistance activity-it is important to use the pain response to help determine when you are ready for this but, using resistance bands and body weight through your natural ranges of motion will help you recover your full mobility and reduce pain more quickly.
Final Phase of Injury:
- Strengthening- exercises in a controlled environment will be demonstrated and then performed to return the shoulder to pre-injury status. Starting easier and progressing to more difficult as your shoulder begins to strengthen.
- Rockwood CJ, Williams G, Young D. Disorders of the acromioclavicular joint. In: Rockwood CJ, Matsen FA III, editors. The shoulder. 2nd edition. Philadelphia: WB Saunders; 1998. p. 483–553.
- Rockwood, C. A., and D. P. Green. “Injuries to the acromioclavicular joint. Fractures in adults.” (1984): 860-891.