AcromioClavicular Joint

The AC joint

Keywords; acromioclavicular joint, chiropractic help, arm pain, frozen shoulder, rotator cuff strengthening.


The AC joint acts as a pivot giving stability to the shoulder girdle. It's key in the Chiropractic Help understanding of arm pain.

Your shoulder consists of four joints, one of which is the Acromio-Clavicular joint. The acromion is the bone at the highest point of the scapula, right at the tip of your shoulder, lying just above the socket.

The acromion, part of the shoulder blade or scapula, articulates with the collar bone, or clavicle at this joint.

The AC joint contains a small disc and is particularly prone to wear and tear, or arthrosis. It is second only to the thumb in the arthritis stakes. Most people by the age of 40 have a degree of degenerative change within the joint, which contributes greatly to the syndromes causing limited shoulder range of motion, so common in the 50 plus patient. This is why chiropractic care of the AC is so important, to keep it free and mobile.

During shoulder movements, the clavicle rotates, mediated by the Subclavius muscle. This little muscle sits right under the collar bone, having a very important function in all movements of the shoulder.

Can you see it below the clavicle - collarbone - in pink?

The collar bone is firmly attached to the Acromion and the Coracoid process by very strong ligaments. So strong that often the collarbone will fracture, rather than the ligaments tear. It's fortunate because bones heal better than ligaments.


Here you can see the upper arm ( Humerus ), the Clavicle and three parts of the Shoulder Blade (Scapula):



  1. Glenoid or socket where the Humerus fits
  2. Coracoid for the attachment of ligaments, anchoring the clavicle, and certain muscles
  3. Acromion for the clavicle

When raising the arm above the head, the scapula rotates, the collar bone acting a strut, connecting the shoulder to the sternum, or breast bone, giving stability and support to the shoulder girdle.



A fall on the shoulder drives the acromion downwards whilst the collar bone is held up by strong neck muscles, the trapezius and the sternocleidomastoideus, rupturing the AC joint capsule.

Likewise falls onto the outstretched hand can transmit enormous forces to the AC joint; either the ligaments anchoring the clavicle to the scapular may be torn; a strain, partial or complete rupture. The AC may rupture, or the clavicle itself may fracture. Usually these heal with immobilisation in a sling for three weeks, with strapping of the AC joint though occasionally surgery may be required. Many sportsmen have ruptured AC ligaments, allowing the clavicle to pop up. It looks serious, but most attest to the fact it gives little trouble after a few months.



Notice the space between the ball of the humerus and the overhanging acromion. It's through this space that the tendon of the very important supraspinatus muscle passes.

Very occasionally tumours of the lung may invade the shoulder. Smoker? Expect trouble, because it's coming.


Frozen Shoulder

Chiropractors are trained to adjust and mobilise the AC joint, vital for the management of shoulder conditions such as Frozen Shoulder , when it feels as though the AC-joint has turned to concrete, causing severe arm pain.

Chiropractic help treatment of many other shoulder conditions, all of which may cause arm pain, such as Rotator Cuff syndrome are also dependent on correction of any AC-joint fixations.



Immobilisation Arthritis

The Acromioclavicular joint is the second most likely (after the thumb) structure to become arthritic. In part, because of so much use - every time you move your arm - and partly because of so many falls on the arm and shoulder.

New research is now proving that when a joint becomes fixated, fluids vital for the healthy nutrition of the joint cartilage are not adequately replenished. This leads to diminished oxygen and nutrients and a build up of noxious wastes in the joint. For more about Immobilisation Arthritis click here. IMMOBILISATION ARTHRITIS ...



Arm pain Quick Dash questionaire

DASH - Disability Arm Shoulder Hand

Many folk find it very difficult to assess just how bad their arm pain is. The Quick Dash score gives you a more objective measure of your pain.


From the medical literature

Legendary shoulder expert, Dr Neer, proposed that degeneration of the acromioclavicular joint may contribute to subacromial impingement and a number of other authors have supported this hypothesis. Arthritic spurs that protrude inferiorly from the undersurface of a degenerative acromioclavicular joint can contribute to irritation where the supraspinatus tendon passes beneath the AC.

In 1977, Kessel and Watson brought additional attention to the acromioclavicular joint as a cause of subacromial impingement. They found that patients who had so called painful arc syndrome could be divided into three categories.

Approximately two thirds of the ninety seven patients in the study had lesions of either the posterior or the anterior aspect of the rotator cuff. All of these patients had resolution of the symptoms after subacromial injection of a local anesthetic and a steroid or division of the coracoacromial ligament.

The remaining patients had pain in the superior aspect of the rotator cuff, which usually was associated with degeneration of the acromioclavicular joint. The authors found that excision of the distal one centimeter of the clavicle provided consistent relief of the discomfort.


Penny and Welsh subsequently found that osteoarthrosis of the acromioclavicular joint can lead to failure after the operative treatment of subacromial impingement. However, resection of the AC should not be performed routinely for all patients; rather, the joint should be operated on only if the patient has symptoms in the region of the joint and if osteophytes definitely contribute to pain when raising the arm. See the Journal of Bone and Joint Surgery, volume 1854, for more details. 


Fish Soup

The ratio of dietary omega 6 to 3 fatty acids is vital in the fight against inflammation in the body. When it's high with too much ω6, or little ω3, the organs becomes angry, red and inflamed.

To raise your omega 3, try making this delicious, simple fish soup recipe regularly.




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IMPORTANT CONSIDERATIONS

Every meal should include some raw food. Perhaps an apple for breakfast: apple diet ... lettuce and peanut-butter sandwich for lunch, and with dinner don't forget our simple Olive Garden salad recipe ...


AcromioClavicular Joint


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Interesting challenges of the day

1. Mrs D, a 78 year old woman has very severe sacroiliac joint pain, and even more severe cramps in her right leg. There are two problems; she is on two diuretics but no slow K. Taking her temporarily off one diuretic and adjusting the SIJ brought 50 percent relief within four days. 

2. Mr S, a 48 year old man, has right low back pain, groin pain and a numb feeling in his lower leg when he sports. For six months he's been off football. He too has two problems; a very treatable lumbar facet syndrome and a very serious blocked artery in the groin; it's called intermittent claudication. Smokers beware.  

3. Mr S looks like the leaning tower of Pisa; he has a slipped disc at L5 making him lean towards the opposite side. It's called the postero lateral disc hernia; we'll fix it, but he has to stop for a week or two. Antalgias are serious so take them seriously. 

4. Mrs V too has  two conditions; a chronic low grade sciatica giving her an ache in the right leg, and a threatening Morton's neuroma. She's glad I'm back in Holland; chiropractic fixed it before, and we'll fix it again. 

5. Mrs W is one of the lucky ones, says her doctor. I agree. He says only 40% of patients with lumbar stenosis have a successful operation. We fixed a nasty slipped disc three years ago, but it came back two years later; the surgeon did a fine job but she has a weak ankle now giving her subtalar joint pain; it's routine stuff. 

6. I myself had an acute exacerbation of a femoral nerve lesion last year. One immediate treatment of the new strain by my colleague has fixed the pain in the lower back, but there's some residual numbness in the lower leg; no soaring tomorrow alas.

7. This lady is a 86 year old woman with a 63 scoliosis. Chronic lower back has been her lot in life but she's well pleased with chiropractic and comes for chiropractic help once a month; some conditions you can never cure.

8. She is an 78 year old woman, is doing remarkably well with a bad sciatica. But over 200 pounds she is not losing weight; in fact, gaining despite my suggestions. She's high risk for a stroke. I have referred her to a dietician to crack the whip.

9. A 61 year old man with upper cervical pain yesterday; it's not severe but also not getting better of its own accord. He's afraid it may turn very acute as when I treated him three years ago. Since then it's been fine. 

10. A 64 year old woman has had scheuermanns disease; it's left her with a spinal kyphosis and chronic middorsal pain. She responds well to chiropractic treatment provides she come every six weeks or so for maintenance treatment.

11. Mrs C has been having severe headaches, and taking a lot of analgesics. It's a non complicated upper cervical facet syndrome, and she's doing well.

12. Mrs D, a middle aged woman with hip pain of one year duration, despite other treatment. Xrays reveal an impingement syndrome and early hip arthritis. There's much to be done.

13. Mrs B has had one of the nastiest of conditions; vertigo caused by a disturbance in the inner ear. Falling repeatedly and vomiting she consulted her doctor but medication didn't help. After two sessions of the Epley manoeuvres she was 50 percent better. After two weeks 75 percent improved. No longer vomiting all falling. She's not enjoying the Brandt Daroff home exercises.

And so the day goes; chiropractors shouldn't be treating the elderly most medical sites state but that's so much bunkum.



Have a problem that's not getting better? Looking for a different slant on your pain? Want to pose a question?


Interesting questions from visitors

CLS writes:

Greetings, Dr B.
You helped me quite some time back with a soothing and professional response which turned out to be exactly correct. I now consult a local chiropractor. You write a superb newsletter, too.

Your own unresolved problem. Pose a question

Knowing that up to 70% of the time the correct diagnosis is made with no examination, no special tests, no xrays, but just from the history, there's a fair chance I can add some insight to your unresolved problem. But at least 30% of the time, I may be quite wrong! Give plenty of detail if you want a sensible reply.


You visited this chiropractic help site no doubt because you have a problem that is not resolving and want to know more about what chiropractors do.

The quickest and most interesting way is to read one of my ebooks of anecdotes. Described by a reader as gems, both funny and healthful, from the life and work of a chiropractor, you'll love them. Priced right at $2.99, though Kindle fiddles the price without telling me.