Where’s the Shoulder Pain Coming From?

Shoulder pain can be produced by a wide variety of issues. The shoulder region is one of the most complicated structures in the body (biomechanically speaking). This is because so many other areas tie into the functionality of the shoulder. Sometimes it isn’t even actually the shoulder that is the problem. In fact, when patients tell me their shoulder hurts, my first job is to figure out exactly what part of the body they are referring to. Is it the front of the shoulder around the A/C joint? Could it be pain at the top of the shoulder in the upper trap area? Is it the pectoralis region? At the rotator cuff or glenohumeral joint? At the Scapula? Is it the underlying ribs? Alternatively, could it actually be radiating or referral pain coming from the neck? In no other region in the body are there so many things to check.

 

Acromioclavicular (A/C) Joint Sprain

Acromioclavicular Joint Anatomy

The shoulder girdle is not actually held onto the thoracic cage by any truly supportive or weight-bearing joint. Nope, unlike the pelvic girdle, it is all muscle that bears that burden. There is however one bone that connects the shoulder to the rest of the body. This would be the clavicle. The clavicle connects to the sternum at one end and to the shoulder blade at the other end. It is very important in helping to coordinate the complex movements and incredible range of motion of the shoulder.

The connection between the shoulder blade and the clavicle is termed the acromio-clavicular joint, or A/C joint for short. This joint is surprisingly mobile. If you think about it, it has to be in order for the scapula to move as much as it does. The connection between the clavicle and the scapula is made possible by a strong fibrous ligament called the acromioclavicular ligament (surprise surprise), and two other strong ligaments called the conoid and trapezoid ligaments. These three ligaments help to keep that A/C joint aligned and anchored.

Rotator Cuff Pathology

Rotator Cuff Anatomy

The rotator cuff complex is a group of muscles surrounding the shoulder joint. This includes the supraspinatus, the infraspinatus, the teres minor & major, and the subscapularis. These 5 muscles provide support and stability to the shoulder joint—which is one of the most mobile and therefore unstable joints in the body. It is a ball and socket joint with a big ball and a small socket. This joint would be very unstable if it did not have some means of keeping the ball centered in the socket. This is where those five muscles come in. They envelop the joint and pull the ball tightly into the cup. So, if these muscles become weak or inactive and/or are overloaded by a strong lifting maneuver, they can rip.

If the rotator cuff is compromised, then the joint will likely not stay centered throughout its movement. This can lead to clicking, popping, restricted motion, wear & tear, pain, and eventually degenerative changes. This is why it is so important to ensure proper rotator cuff health or recovery if injured. The most common cause for rotator cuff damage is overhead lifting. But, there are several more mechanisms of injury and much more at play than you might think. Many times a person will simply overload the rotator cuff causing a rip in the muscle or tendon. This can happen when lifting too much weight upwards, but can also happen while lowering something heavy from a high shelf. Other times, it is a repetitive injury that occurs over time. This can happen at the gym, or during a sport like baseball.

You may feel a discomfort or odd movement at the time of activity, but later feel the injury more severely. Sometimes it takes weeks or months for a person to notice significant changes. This is because while the damaged rotator cuff itself may not produce much pain, the resulting abnormal motion causes stress and inflammation that gets worse over time after the initial event.

Researchers are now providing evidence that rotator cuff injury may not happen in a vacuum. This group of muscles may be predisposed to injury in people who have abnormalities in the position of their shoulder blades. People who roll their shoulders forward and down may be putting their rotator cuff muscles in a vulnerable position where they are loaded under additional stress and therefore are prone to injury. You can see that this is true for yourself simply by

Try the Following:

1. Sit up straight with your shoulders back, then clap your hands over your head.
2. This should be easy (unless you already have shoulder problems).
3. Now, roll your shoulders forward and slump in your chair. Clap over your head again.
4. What did you notice? It was much harder this time right?

Why is this? The shoulder blades control the angle of movement of your arms. If your shoulder blades are not positioned correctly, then chances are that your arms are going to have a much harder time moving overhead properly because you are having to fight at an abnormal angle and recruiting additional muscle strength to do so. This puts stress on the rotator cuff and predisposes it to damage. This is why it is often not just enough to address the rotator cuff, but to also retrain the scapula to work correctly again. If you don’t fix this part, you’re likely going to have another episode in the future and cause more damage.

Retraining the scapula usually means getting them to sit flatter on the ribcage along with correcting postural abnormalities of the cervical and thoracic spine (neck and upper back). Chiropractic & physical therapy for shoulder are the mainstay of our treatment here at Reactivate. Even if surgery is needed, this treatment is still necessary to retrain the body and correct the underlying issue. Sometimes the damage is too great, and requires surgical intervention. The general consensus is anything over 50% tear warrants surgery. Though I typically refer for surgical consult for large tears, severe loss of strength, or serious dysfunction that does not improve with conservative treatment. Even after surgery, it still needs to be rehabbed. Those muscles/tendons need treatment and the joint needs to be stabilized once again. Left unattended, rotator cuff problems typically lead to osteoarthritis or even frozen shoulder.

 

Subacromial Bursitis

Subacromial refers to the area under the outer shoulder blade. Bursitis is inflammation of the bursa. Bursa are fluid filled sacs that reduce friction from neighboring structures. They are like tough water balloons that allow surfaces to glide past each other smoothly reducing the chances of damage. You have bursa throughout your body including right underneath the outer most part of the shoulder. This bursa is designed to reduce the friction between the bones and the tendons that lie between the shoulder blade and upper arm. Bad mechanics in the shoulder can lead to damage of the underlying structures including the bursa.

If the bursa is inflamed, it swells becoming larger and more painful as pressure and additional friction are created. Subacromial bursitis is often associated with shoulder impingement (addressed below) which can be a mechanism of damage for the bursa. If you are going to fix the bursitis, you must improve the mechanics in the joint. This typically involves correcting postural abnormalities in the blade and neck/upper back region, manipulating the shoulder joint itself to improve motion and position, and treating any soft tissue abnormalities in the surrounding musculature. I also typically recommend we perform an injection into the shoulder with medication that decreases the inflammation and promotes healing. Usually we can get these bursa to calm down and return to normal using these methods.

 

Shoulder Impingement

If you feel a pinching sensation in your shoulder and/or resistance when you raise your arm up, then you may be experiencing shoulder impingement. Impingement occurs when the arm is lifted up and tendons are pinched between the head of the humerus (ball of the upper arm) and the underside of the acromion (hook of the shoulder blade). This happens because the humerus is not moving correctly.

The upper arm has a big ball on the end of it that fits into a socket on your shoulder blade. It is supposed to roll and glide downwards at the same time so that it stays centered inside the socket. Many people have a problem with this action due to an abnormal muscle activation pattern or imbalance. This causes the downward slide to be restricted and the consequence is the ball rolling up to the top portion of the socket. When the ball rolls up, it bangs into the top part of the shoulder blade where there is an overhanging structure called the acromion. Whatever is in between gets compressed. This is usually the supraspinatus tendon and/or the biceps tendon and/or the joint capsule.

Over time, dysfunction in those tendons and can further drive bad biomechanics in the shoulder region producing inflammation and bursitis. Just like any other biomechanical problem, the idea is to reduce pain and inflammation, then correct the mechanics by retraining the body through rehab and manipulation.

 

Shoulder Tendinopathies

There are a variety of tendinopathies that can occur in the shoulder region. Some of these are due to lifting injuries either acute or repetitive in nature. Some of these are due to impingement syndromes like the one described above. In all of the situations, abnormal biomechanics play a role in the dysfunction and damage done to the tendons that lead to these tendinopathies. The more common tendinopathies include the rotator cuff complex, the biceps tendons (the biceps inserts into the shoulder region) and pectoralis tendon (both minor and major insert into shoulder region). Some are severe enough to require a surgical consult. Others can be dealt with conservatively. Typical treatment includes ultrasound to help heal and decrease inflammation, manipulation to correct joint mechanics, and rehab to correct muscular balance and movement patterns. Shoulder blade dynamics almost always need to be addressed as well.

 

Shoulder Strains

While it is a little more rare and less serious to be dealing with a muscle strain in the shoulder area, they do happen, especially in athletes and weight lifters. This occurs when the muscles involved are overloaded. They can include the rotator cuff muscles, the deltoid, rhomboids, and pectoralis muscles. Sometimes the injury is more of a repetitive nature rather than an acute overload. These tend to heal pretty well with ultrasound and basic rehab. Manipulation of the soft tissue and joints is also warranted.

 

Glenohumeral Arthritis and Frozen Shoulder

The glenohumeral joint is the shoulder joint. It is the connection between two bones: the glenoid fossa (a cup-shaped part of the shoulder blade), and the head of the humerus bone (upper arm bone). Bad biomechanics typically leads to this outcome. When I say bad biomechanics, I am referring to the position and movement in a joint. If you can imagine a hinge on a door, that hinge is supposed to come together straight and flush so that the door can move correctly. These two things (position and movement) are essential for the door to swing freely and avoid grinding and friction. This is also true of any joint in the body.

Problems with position and movement lead to excessive stress, wear, and tear. Eventually the cartilage in the joint is worn down and arthritis sets in. Osteoarthritis is the wear and tear disease of joints. There is pain, swelling, loss of joint space, deformity in the joint, bone spurs, and several other nasty things that occur in this process.

Osteoarthritis is by far the most common kind of arthritis affecting the shoulder joint. Long standing shoulder dysfunction or short-term dysfunction after major shoulder trauma can even lead to adhesive capsulitis aka frozen shoulder. This condition occurs when the ligaments/capsule around the shoulder become so inflamed and stiff that a person cannot move the shoulder joint. This is why it is so important to get to these problems early on. Don’t mess around with this stuff. Get it checked out ASAP by somebody that deals with biomechanical problems. The longer the problem has existed, the longer the treatment is and the less function we can recover.

So, how do we fix it? We must retrain the body to put that joint in the right position and move correctly again. Manipulation to free up restrictions and improve the position of the joints is first course. Therapies like electro-stimulation and ultrasound can be useful to decrease muscle spasm, pain and inflammation. Rehab to train the muscles to keep the proper position and movement are also essential. I also highly recommend that we do once weekly shoulder injections with medicines designed to deflame the joint and promote healing.

 

Labral Tear

The labrum is the thin fibrocartilaginous lip around the cup of the shoulder socket. Its job is to help keep the head of the humerus (ball) centered in the shoulder socket. There are 3 kinds of labral tears that can occur. They are usually associated with some sort of shoulder trauma. The most common labral tear is called a SLAP lesion (Superior Labrum Anterior Posterior). It’s basically a lesion in the top part of the labrum from front to back. These are graded in severity depending which structures are involved to which degree.

The SLAP lesion can result in instability of the biceps tendon which is attached to the top part of the labrum. The Bankhart lesion is less common and involves the lower half of the labrum and a ligament called the inferior glenohumeral ligament. This is often seen with shoulder dislocations. The Bennet lesion is the least common. This occurs to the back part of the shoulder joint and is often associated with rotator cuff tears in the back part of the shoulder joint. Labral tears often require surgery. It is necessary to acquire advanced imaging like an MRI to find these lesions and make a determination if a surgical consult is necessary. Even after surgery, rehab is still required to treat the biomechanical dysfunction and return as much function as possible to the area.

 

Rib Pain Mimicking Shoulder Pain

Rib pain can also express itself as shoulder pain especially in the ribs underneath or near the shoulder blade. I can’t tell you how many times a shoulder complaint actually turns out to be a rib dysfunction. Because the ribs travel right underneath the shoulder blades, it can often be confused for a shoulder blade issue.

It is pretty common to see rib heads subluxated (moved out of place) at their connection with the thoracic spine. This sends sharp or stabbing pain around that rib under the shoulder blade and sometimes into the front of the rib cage. Sometimes people even think they are having a heart attack because the pain seems to shoot through their chest. People typically complain of problems breathing with rib dysfunction. Sometimes all that rib requires is a gentle manipulation. Other times we need to dig deeper to figure out why that rib head is subluxating. You can read more on rib pain under the Spine & Ribs Section.

 

Referring Shoulder Pain

Pain can actually refer down into the shoulder region from damage to structures in the neck or by means of damage or contracture in the muscles connecting the neck and shoulder. The levator scapula muscle likes to refer pain into the shoulder blade in overuse injuries. It is a muscle that connects the neck to the shoulder.

I like to think of this muscle as the first responder. If you have a problem in the neck (like a torn disc), this muscle often shrugs up in an attempt to guard and restrict motion. It may be a neck problem that is the real issue. A facet joint can refer pain down into the top of the shoulder. This is the joint at the back part of the spine. Irritation of these joints in the region of the neck and upper back can lead to shoulder pain. Organ pathology can also refer to the shoulder region. Ulcers, gallstones, heart problems, and lung pathology can all produce radiating pain into the shoulder. These sources of referral pain must all be considered.

 

Radiating Shoulder Pain

Radiation indicates irritation or damage to the nerve roots exiting the spine. If one of the nerves in the neck is being pinched, it can send pain down into the shoulder or even the arm or hand. People with true radiating pain will have associated neck pain. They may feel electric-like sensations in the upper extremity, or possibly burning. There may be associated numbness and tingling or weakness. Nerves are usually entrapped at the bony exit between the vertebra compressing or irritating either the nerve root (branch off of the spinal cord), or in more severe cases, the cord itself could be compressed inside of the spine.

The Source of compression may be bony like in stenosis from arthritis. Alternatively, compression could occur because of a herniated disc. There are some other more rare, but more serious diseases that can compress nerves including cancer or infection and a good Chiropractic physician always bears this in mind when performing an examination.