The shoulder region is one of the most complicated structures (biomechanically speaking) in the body. This is because so many other areas tie into the functionality of the shoulder. In fact, when somebody tells me their shoulder hurts, my first job is to figure out exactly what they are talking about and isolate the area. Is it the front of the shoulder around the A/C joint? Is it the top of the shoulder in the upper trap area? Is it the pectoralis region? Is it the rotator cuff or glenohumeral joint? Is it the Scapula? Is it the underlying ribs? Is it actually radiating or referral pain coming from the neck? In no other region in the body is there so many mechanics to check. This is exactly why it is so important to seek out a professional that can distinguish these completely different issues from one another to derive the correct treatment. Having said that, I will try to address some of the most common issues affecting the shoulder.
Acromio-Clavicular (A/C) joint
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.
It is common in certain types of trauma, like motor vehicle accidents and sports, for one or more of these ligaments to be torn. This is an A/C sprain. They are often graded by their severity and how many ligaments are involved. The worst ones need to be repaired surgically.
Sometimes repetitive type injuries can also create microdamage to the ligaments causing dysfunction and misalignment of the A/C joint. Either an acute trauma or repetitive chronic trauma can cause instability in the A/C joint and lead to osteoarthritis if left untreated.
If the A/C issue does not require surgery, then conservative physical medicine is warranted. If surgery is performed after a trauma, then physical medicine is warranted after a short healing/resting period. My approach is often a combination of ultrasound, taping, manipulation, and specific rehab.
Rotator Cuff Pathology
There is a more thorough and specific section on the rotator cuff under the conditions tab, but I will briefly discuss it here as well. The rotator cuff is a group of 5 muscles whose primary job is to ensure that the head of the arm bone stays inserted onto the shoulder blade. The arm bone (humerus) has a large round knob at the end of it that inserts into a smaller round cup (glenoid fossa) on the shoulder blade (scapula): hence this joint is called the gleno-humeral joint. The joint is naturally designed this way to obtain a big and versatile range of motion. Here is the problem, the glenoid is not very deep and the head of the humerus is fairly big so there is not much support. This joint would be very unstable if it did not have some means of keeping the humerus inserted into the glenoid fossa. This is where those five muscles come in. They envelope the connection between the two bones and pull the ball tightly into the cup. So, if these become weak or inactive and/or are overloaded by a strong lifting maneuver, they can rip. If they are damaged, then they no longer do their job and the ball can slip out of the cup. This instability creates popping, grinding and slipping of the joint that can lead to damage over time. There is typically an associated problem with the positioning of the scapula as well. Often people with rotator cuff problems develop osteoarthritis in the joint if left untreated. The degree of instability depends on how bad the damage is and whether the muscle belly is injured or if it is the tendon… The tendon is the worse situation. 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 care and to be strengthened and the joint needs to be stabilized once again. Left unattended, rotator cuff problems typically lead to osteoarthritis of the glenohumeral joint and possibly frozen shoulder.
If you feel a pinching sensation in your shoulder when you raise your arm up, then you may be experiencing shoulder impingement. There is an easy test that you can do that is evidence of shoulder impingement if positive: Place the arm of the affected side straight out in front of you with your palm flat down. Now bend your elbow to 90 degrees so that the arm is parallel to your chest. Now take your other hand and grab the elbow of the affected side. Place your non-affected elbow on top of the hand of the affected side. Keeping the upper arm of the affected side straight out in front, use your non-affected hand and elbow to push and rotate your affected hand downwards. This is essentially Hawkin’s impingement test. If this causes pain up in the shoulder of the affected side, then you might have impingement syndrome.
This action occurs when the head of the humerus rolls up and tendons are pinched between the greater tuberosity and the coracoacromial arch (you may have to google these terms). It’s basically that the top of your arm bone and part of your shoulder blade are coming together and compressing the structures that exist between the two. This happens because the humerus is not moving correctly. You see the humerus 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 retarded 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 coracoacromial arch. Whatever is in between gets compressed. This is usually the supraspinatus tendon and/or the biceps tendon. Over time, this can create substantial damage and dysfunction in those muscles and can further drive bad biomechanics in the shoulder region.
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.
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.
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 injury 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.
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 to that door opening and closing correctly. This is 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 osteoarthritis sets in. Arthritis simply means inflammation in the joint. 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. There are other types of arthritis, but we won’t get into those here because osteoarthritis is by far the most common kind affecting the shoulder joint. So, how do we fix it? We must retrain the body to put that joint in the right position and move correctly again. The longer the problem has existed, the longer the treatment is and the less function we can recover. Long standing shoulder dysfunction or short-term dysfunction after major shoulder trauma can even lead to frozen shoulder. This condition occurs when the ligaments around the shoulder become so stiff and hard 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 labrum is the thin fibrocartilaginous lip around the cup of the shoulder socket. Its job is to help keep the head of the humerus centered in the shoulder socket. Attached to this labrum is one of the biceps tendons. 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.
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.
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. A facet joint can refer pain down into the top of the shoulder. The levator scapula 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 just be a neck problem that is the real issue.
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. Again, the problem may actually be in the neck.
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.
Well, as you can see, shoulder pain can be produced by a wide variety of issues. Sometimes it isn’t even actually the shoulder that is the problem. Don’t try to self-diagnose shoulder problems. Without the proper training it isn’t much more than a crapshoot. If you have shoulder complaints, go see somebody that knows what they are doing. It could be serious and delaying a proper diagnosis could have some life changing consequences. Give us a call today if your shoulder hurts. I would be glad to sit down with you and figure out what is really going on.