How To Treat Shoulder Pain Caused By AC Joint Separation

Acromioclavicular joints or AC joints are easily injured and susceptible to secondary issues such as arthritis, laxity, and shoulder pain.  Often referred to as a “separated shoulder”, an AC separation takes place when the ligaments that stabilize the collar bone (clavicle) and the shoulder blade (scapula) become damaged.

The acromioclavicular joint is the connection between the lateral end of the clavicle (collar bone) and the lateral end of the scapula (shoulder blade).  This bony section of the scapula is referred to as the acromion. The AC joint creates a stabilizing union between the front and back of the shoulder girdle.  It’s important to note that when healthy this joint has ample mobility, which allows for significant motion of the shoulder.  The AC joint forms an important archway that protects the rotator cuff and shoulder joint below.

Stabilized by a joint capsule, the acromioclavicular joint encompasses the ends of the clavicle and acromion along with several ligaments. Because ligaments attach bones to bones, when the AC joint ligaments, located under the clavicle, are damaged with a separated shoulder they create a downward pull to the clavicle and AC joint.

What Causes a Sprained AC Joint?

Falls are often the cause of separated shoulder injuries.  The AC joint is not overly stable and its location makes it quite vulnerable to injury.

The two most common mechanism of injury are:

  • Landing on the lateral part of the shoulder forcing the shoulder downward.
  • Landing on an outstretched arm or elbow, which forces the shoulder joint upward into the undersurface of the acromioclavicular joint.

With either of these, the AC joint capsule is disrupted and the stabilizing ligaments are compromised.  The grade or degree of separation depends upon the level of damage to both the ligaments and capsule.

Grades of Separation

Shoulder Separation, Grade I

Mild disruption of the AC joint capsule resulting in minimal instability of the joint.

Shoulder Separation, Grade II

Moderate disruption of both the AC joint capsule and stabilizing ligaments resulting in moderate instability of the AC joint.  Partial tears of both the AC joint capsule and the stabilizing ligaments are present.  You’ll notice moderate laxity of the AC joint with a visible elevation of the outer clavicle when holding a weighted object with the injured arm at your side. The amount of elevation with a Grade II AC sprain is typically ½ to 1 inch when compared bilaterally.

Shoulder Separation, Grade III

Significant disruption of both the AC joint capsule and stabilizing ligaments resulting in significant instability of the AC joint.  Complete tears of the AC joint capsule and possibly complete tears of at least some of the stabilizing ligaments are present.  There is visible laxity of your acromioclavicular joint with a visible elevation of the outer clavicle with the injured arm resting at the side of your body.  When your arm is reached across your body towards the back of the other shoulder, the abnormal lateral clavicle elevation increases.

AC Sprain Grade IV to VI’s are much more severe and are based on the hyper-mobility of the acromioclavicular joint.

Signs & Symptoms You Have an AC Joint Sprain

  • Pain and localized swelling on the top of the shoulder at the acromioclavicular joint.
  • Swelling and or bruising may be present on the top of the shoulder.
  • An obvious bony lump on the top of the shoulder, which is the end of the displaced collarbone.  The higher the grade of shoulder separation, the larger the elevation of the outer tip of the clavicle.
  • Limited range of motion (ROM) and pain with any lifting of the arm.
  • With Grade II and Grade III AC joint sprains, a “clicking” or shifting can be felt in the AC joint with shoulder motion.
  • With active motion (when you move your arm) or passive motion (when someone else moves your arm) of the injured arm horizontally across the body towards the back of the other shoulder, significant AC pain will occur.

Treating a Separated Shoulder

  • Ice the top and front of your shoulder with the elbow flexed to approximately 90 degrees and supported.
  • Using an arm sling is helpful if having pain or clicking with walking.  This helps to support the weight of your arm while restricting motion.
  • Once a fracture is ruled out, early motion is started to reduce stiffness and pain.  No horizontal adduction motion (horizontal movement of the arm across the midline of the body) is allowed until you have full pain-free motion.
  • Easy pendulum swings to help regain motion of the shoulder.
  • A shoulder strengthening program can be started early with a Grade I & II sprain as tolerable.  Starting with rotational motions and progressing with overhead lifts as tolerable.  Continue to avoid horizontal adduction as long as possible.

Questions a Pro Athlete Would Ask To Heal Quickly and Safely

As always, my goal is to help you get back in the game as quickly as possible while ensuring you can return safely.  Ask the following questions—the same ones a smart professional athlete with a Separated Shoulder would ask his sports medicine specialist, so you too can recover quickly and safely:

  1. What grade is my shoulder separation?
  2. Do you think I can manage this AC joint sprain with rehab without needing surgery?
  3. Do I need any special padding, taping, or altering of my sports equipment to reduce the chance of reinjuring this acromioclavicular joint? What specific lifts, activities, and motions do I need to avoid to allow my AC joint separation to heal quickly?

Sports Medicine Tips For an AC Joint Separation

  • Little Need for a Knife – AC joint surgeries are not overly common unless the instability is severe or the limitations are complex.
  • Sleep Well? – Don’t plan on sleeping on the injured shoulder for a while.  I severely separated my right AC joint in a winter mountain bike race on a ski slalom course (I know, it’s not the smartest thing that I’ve ever done but it sure was a lot of fun…until I crashed!) in Vermont in 1994 and I still can’t sleep on that side!
  • Posture is a Factor – Any position, any movement or any activity that rounds your shoulders will worsen your pain. It’s that simple.
  • Ice, Motion, Ice – Ice it, move it in pain-free directions and then ice it again.  Simple formula with fast results.
  • Upper Back Squeezes – While sitting or standing tall, relax your arms while you squeeze your shoulder blades (scapula) together while exhaling hard.  Hold for 2 seconds and repeat 10 times.  Do this drill as much as possible to stretch out your chest muscles, strengthen your shoulder stabilizing muscle and, very importantly, decompress your AC joint.

Author: Mike Ryan

After 26 seasons as a full-time certified athletic trainer and registered physical therapist in the National Football League, Mike Ryan has outstanding first-hand experience. His unique professional and athletic background has sharpened his skills in the arts of sports injury management, elite rehabilitation, performance enhancement and injury prevention. Mike is now taking his experience to mainstream America. His mission is simple: Sports Medicine advice that is easy to use and brings fast results. Learn more about Mike Ryan

20 thoughts on “”

  1. Hey guys, 3 months ago I was in a motorcycle crash which gave me a grade 2 Ac seperation. I have the bump on my shoulder, with lots of popping.I have been getting back into the gym noticed a lot of pain in the joint so went back to the Ortho. He said I had weightlifter shoulder gave me a cortisone shot and said come back in a month if it’s not better to discuss surgery. Does anyone know if I get the surgery which shaves the bone, will this help to reduce the bump? I hate having the bump, it’s been really depressing.

    1. The shaving may help with some of the visible bump but most of the bone shaving is on the underside of the clavicle. A Mumford procedure will cut the end of the clavicle or collarbone off but it is not a procedure to do simply for cosmetic reasons. Advice: Focus on how functional your shoulder is based on strength, range of motion and ability to be active painfree, regardless of the bump.

  2. HI Mike,

    I have a grade II or III AC separation yesterday 7/15/17. The clavicle is visibly up or a half inch, looks weird. I have read where someone assists pushing the clavicle into position and then taping it. Tape is left it on for three weeks so it would heal in position. I can’t find anyone in my area so far that can do this. Do you have any suggestions as how to find someone to do this? I live in Oakland, CA

    Thanks for any help!


    1. Hi Wyatt, As an athlete with a chronic Grade 3 AC separation for over 20 years I can tell you that your presumably Grade 2 AC sprain is very manageable….once you get over the cosmetic factor. The tape MAY help slightly with the appearance but chance are it will not impact the looks or the performance of your AC joint.
      I suggest you focus on:
      1. Improved posture to allow the clavicle to sit lower to the scapula.
      2. Ice the AC joint when sore.
      3. Improve deltoid muscle strength to protect the AC joint and fill in the areas aroudn the joint…looks better.
      4. Avoid activities which impact the shoulder and/or bent elbow.
      Keep me posted. MDR

  3. Since having my shoulder AC joint surgery I have found others on line that had Grade V and did not have the surgery. Too late now but maybe I could have been ok without surgery. It was a very trying time and not easy to get answers for my particular case. My surgeon left it up to me, I assume my level of functionality was good for the degree of separation. All I can do now is hope I made the right choice.

    1. Wyatt, I know exactly what you’re dealing with. I had a Grade 3 shoulder separation from a winter downhill bike race crash. I lived with it completing 6 Ironman triathlons, 100+ other races for 21 years….then I had surgery on the AC joint. With that being said, there is no set rule as to if you DO or DON’T have surgery on a Grade 3,4 or 5 separated shoulder.
      The main factors to evaluate when making that decision: Shoulder pain, function and strength.
      As for you now after your surgery: Stop looking backwards. NOW is the time be “All-In” with your shoulder. Focus hard with your physical therapist to regain full strength, range of motion (ROM) and function. You have lots and lots of cool things in this world to experience and you need to 2 strong shoulders to enjoy the ride!

  4. It’s just about two weeks since I had a collision on my bike with a car that cut in front of me, and hit with my humeral head and AC joint. I have an elevated clavicle and a bump and felt really bad about it until I read your blog and your story. I get it now. I’m 68 years old, and my plan is to pursue physical therapy like a religious fanatic and get back on the bike. I promised myself a century ride this season, but that’s not going to happen with 6 weeks of PT between now and winter on Long Island. My plan is to start training on the good days after I finish PT and get my distance back, and get myself a wind trainer for the bad weather days. By next summer I’ll accomplish my goal. Thanks for the reality check. It felt great to move out of mourning and into acceptance.

    1. I see you Mark!! Your active approach to (literally) getting back on the bike is impressive and the main reason why you WILL get that century ride in this year! Smart training like the indoor riding and improved handlebar positions will certainly help. Areobars will not be a realistic option early on due to pain and that rounded shoulder position won’t be comfortable for some time.
      I wish you a fast recovery. Keep me posted. MDR

  5. Six weeks ago I separated and dislocated my shoulder in a bicycle crash. The AC separation was originally a grade 5 and my shoulder surgeon thought I would need surgery to keep the bone under the skin. The bone came back down and is now closer to a grade 3 separation, so he is not recommending surgery.

    For the first three weeks I was doing about 2 hours a day of PT (also rehabilitating a posterior labrum tear). I felt better everyday and was optimistic about my recovery. About two weeks ago, my trapezius muscle got so knotted up in a couple areas that my therapist reduced my exercises substantially.

    I’ve been trying to figure out what changed during the two week period to lead to the sudden knots. The only thing I am aware is different is that I was originally wearing a towel rolled up in my arm pit to reduce perspiration. I developed a lot of bacteria growth in the hospital and the odor was very strong. Do you think the rolled up towel was reducing pressure on the trapezious? If so, any suggestions other than keeping a towel in my armpit in the long run?

    Any advice is appreciated.

    Thank you.

    1. Hi Steve, Thanks for your question. I, too, got a Grade 5 AC separation from a bike race accident in a downhill bike race in Vermont in a March snowstorm on the Giant Slolum ski course….not smart, I know! I waited 20 years to have surgery on the injury after about 100 various triathlons/Ironman/road/obstacle races. Needless to say, this is probably a manageable injury for you.
      Your trap is more prone to spasms because it has a new role of holding your entire shoulder girdle up. The missing link to your quick recovery is POSTURE.
      You need to focus on following with the help of your physical therapist and certified athletic trainer:
      1. Relaxing and stretching your pec minor and pec major.
      2. Strengthening your rhomboid muscles.
      3. Lengthening and controlling your seratus anterior muscles.
      4. Gaining great endurance of the shoulder blade-controlling muscles noted above so you can maintain great posture for hours and hours while sitting, standing and exercising.
      When you master these 4 vital steps, your trap will chill out, your distal clavicle will drop back into place and your shoulder rotator cuff strength will double!
      Keep me posted Steve and rehab like a pro. MDR

  6. Hi Mike,
    Thanks for sharing your experience.
    Separated my both shoulder, last was 5 months ago.
    Done a lot of PT and now I try to strengthen my shoulder but some exercices are still painfull, especially push-up.
    Should I go throught the pain or keeping it lite and waiting for improve?
    Thanks a lot!

    1. Answers: No and No. You can’t throttle back too much but the best advice I can give you for working around a separated shoulder is to find the exercises and positions which stress the muscles to get strong without re-creating the AC joint pain.
      For example, adjusting your hand position, posture, depth and/or speed of a pushup will drastically alter your pain.
      Focus on more pulling motions than pushing. This motion will strengthen your upper back, stretch your chest and improve posture….ALL OF WHICH ARE VERY HELPFUL for an athlete with a separated shoulder.

    1. Good question Phil. After 20 years, 6 Ironman triathlons, too many falls on that shoulder and an arthritic AC joint b/c of the Grade 3 laxity, I decided to have the surgery to reduce my pain AND to reduce the source of a potential problem with my current Spartan Race schedule. I had the surgery after the NFL season so I have ample time to heal, regain my rotator cuff strength and properly prepare for my workouts, races, and busy travel schedule. Think of it this way; If I took a hard fall on my injured shoulder in May, my race season is in jeopardy, scheduling surgery then is a major problem and my outcome is poor going into my busy fall football season. Timing is key for surgeries, workouts and an active lifestyle.

      1. Such a wise advice Mike. Sorry for questionning you again but what to expect when falling on an already separated shoulder? I’ve injured both of my shoulder, so if I fall again, no chance it would be on the “good one”… I’m quite afraid of worsening the injury.

        1. Good question Phil. I know you’re a bike rider so, as with any of us who want to….NEED to live an active life, bumps and bruises will happen. I like to think of ways to minimize there risks while still living a life worth living. Can’t live in bubble-wrap, right?!
          >Keeping your shoulder deltoid muscle strong will protect your AC joints.
          >Mountain biking shoulder pads will help.
          >Improved bike handling skills will help keep you on the bike….always a good thing.
          >Tumbling skills can help reduce the stress on the entire body when falls do happen. I used to teach my NFL players coming back from knee and low back injuries to tumble!
          >Loose and mobile chest pec muscles help increase the range of motion of entire shoulder girdle. Your AC joints will thank you.

  7. Hello Mike,
    thank you for a very useful post!
    I separated my shoulder 1 week ago.
    I have decided not to operate. I will wait one year and if I experience much pain and/or problems after that I will consider surgery. Meanwhile I will train with a physiotherapist and follow your advice.
    I live in Norway. Here the way this is operated is coracoclavicular reconstruction using the patients hamstring ligaments. Is this the procedure you will undergo? I have found several scientific studies regarding outcome of operation, but a lot of these seem to refer to older procedures for operation. Could you recommend a scientific study regarding operation outcome of newer procedures? Are long term data available?

    Best regards,
    Andreas W. Paulsen

    1. I, too, recommend your present plan of non-surgery for a year. I had a Grade 3 separation of my dominant shoulder. I eventually had a Mumford Procedure where they cut off the end of my clavicle…..6 Ironman Triathlons, 100+ races and 20 years later! Often this injury proves to more cosmetically concerning than athletically limiting.

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