My “shoulder” hurts, what’s the problem?
What people call the shoulder varies widely from person to person. Some people include the neck, shoulder blade, upper chest, arm, etc. The limits are quite arbitrary. When there is pain in the shoulder, the anatomical site of the pain must be identified in order to make an accurate diagnosis. It is sometimes very difficult, even for an experienced doctor, to make an accurate diagnosis given the multitude of structures and possibilities.
However, a few pointers will set you in the right direction:
Clinically, it is helpful to distinguish between symptoms in the neck and shoulder area by dividing them into three anatomical regions: 1. posterior pain; 2. anterolateral pain; and 3. axillary pain.
1. Posterior pain
Mainly felt in the back of the neck, trapezius and shoulder blade, sometimes radiating to the arm and forearm. It is sometimes associated with headaches, numbness or tingling in the back of the hand (in a way it is the equivalent of sciatica of the upper limb). In general, posterior pain is caused by cervical inflammation (sprain, discopathy, degeneration), muscle tension or spasms, or irritation or compression of nerves in the cervical region that may cause numbness of the fingers. Cervical movements must be assessed to ensure they are complete and symmetric and to see whether mobilization of the neck affects the pain in the shoulder. If so, it is a case of referred pain.
Firstly, it is important that the doctor carry out a neurological examination and order a cervical X-ray (that will often show a pinched nerve between the C5-C6 or the C6-C7 vertebrae, which is very common in people over 45 years of age).
Treatment is usually nonsurgical, unless there are signs of nerve compression (loss of sensation, strength or reflexes). In these cases, specialized imaging (MRI or CT scan) tests must be ordered and the person referred to a specialist (physiatrist, orthopedic surgeon, neurosurgeon) if there is evidence of a risk of neurological damage.
2. Anterolateral pain
Pain in this area is caused by pathologies of the anatomical structures of the shoulder (subacromial space, acromioclavicular joint, rotator cuff, labrum, long biceps tendon, glenohumeral joint). There are therefore a number of possibilities, some examples of which are provided below:
A) Problems in the acromioclavicular joint will mainly be felt at the top of the shoulder; the pain does not radiate much and increases when the arm is crossed over the chest (adduction).
B) Tendinitis and tendon tears (cuff and biceps) cause pain on the side and front of the shoulder (undersurface of the acromion), sometimes radiating to the outside of the arm (or to the biceps in biceps tendinitis). The pain is worse when strength is required to elevate the arm, especially if the arm is raised overhead. The pain tends to be worse at night and sometimes wakes the person up. The amount of pain depends on the movement made. In cases of a severe rotator cuff tear, the pain may be accompanied by weakness or muscle loss in the shoulder blades (ask your partner or a friend to compare your shoulder blades, since you can’t see them yourself).
C) Osteoarthritis of the shoulder and adhesive capsulitis are more insidious and involve a more gradual, less localized malaise, sometimes occurring in the absence of movement, at rest. They are characterized by a certain loss of movement (you can check this yourself by holding your elbows close to your body and then rotating your forearms externally and comparing them or, alternatively, try to put your hand between your shoulder blades, alternating the two sides to compare them).
D) Labrum disorders (e.g., SLAP lesions) are associated with movement, sometimes causing a popping sound or sudden pain (which is quite poorly localized). The pain is not constant; it is felt occasionally when making certain movements.
E) Subacromial impingement and bursitis are also associated with movement, causing pain on the front and side of the acromion during complete elevation or abduction (lateral elevation). The pain increases if the arm is internally rotated at the same time (if the forearm is turned toward the ground).
N.B. Shoulder pathology rarely causes symptoms that extend to the elbow (except for adhesive capsulitis). Should it do so, a cervical cause must be investigated.
3. Axillary or chest pain
Persistent pain in the armpit or upper chest is usually referred pain (unless it is the first symptom of adhesive capsulitis). Special attention must be given to cardiac or pulmonary pathologies if the pain is left sided. The possibilities are numerous and may be of viral (such as herpes zoster) or tumoral (e.g., lymph node in the breast or lymphoma) origin or may stem from irritation of the diaphragm (from an abdominal disorder, for example). Traditional recommendations are in order and it is advisable to consult one’s family doctor or a general practitioner to rule out a life-threatening diagnosis.