Differential diagnosis of pain in the shoulder muscles

One of the most common pain symptoms affecting the upper musculoskeletal system is shoulder muscle pain. Painful sensations can be associated with inflammation of bone tissue and joints, but more often they are directly caused by pathology of the periarticular structures – ligaments, muscles, tendons.

The high percentage of diagnosed diseases of the soft tissues of the shoulder is explained by the specific biomechanics and anatomical structure of the shoulder joint, as well as the physiological characteristics of the structure of tendon and muscle tissue.

It should be noted that the generally accepted concept of “shoulder” is somewhat different from the definition of this anatomical zone by doctors:

• The shoulder is the upper region of the arm, starting from the shoulder joint and ending at the elbow.
• The shoulder girdle is the entire upper surface (girdle) of the arms, connecting them to the body, including the deltoid, minor and major, supraspinatus and infraspinatus, teres and subscapularis muscles.

The shoulder joint and its surrounding tissues are considered one of the most complex and multifunctional structures of the body; the variety of range of movements in it is achieved due to the mobility of the periarticular system, including muscles. The developed muscular-ligamentous apparatus of the shoulder allows a person to perform rotational, circular, flexion, extension, rotational and many other types of movements, but how multifunctional the system of soft tissues and tendons is, so vulnerable is it to various diseases.

Pain in the shoulder muscles can be the result of inflammation, damage to the periarticular tissue itself, but it can also be a concomitant background sign of an underlying disease not directly related to the musculoskeletal system. That is why it is so important to identify the causes of pain and timely diagnosis.

Causes of pain in the shoulder muscles

Periarticular pain in the shoulder is most often provoked by instability of the joint, which in turn can be caused by the following factors:

• Overexertion, sprain of the shoulder girdle during intense strength training.
• Damage, inflammation of the joint capsule.
• Stretching of the muscles located near the joint capsule as a result of compensatory self-correction of joint function.
• Damage to the cartilage of the articular cavity, lack of support for the biceps.

In general, the causes of pain in the shoulder muscles can be divided into three nosological categories:

• Isolating degenerative, inflammatory or traumatic injury to muscle tendons:
  • Rotator cuff tendonitis.
  • Calcific tendinitis.
  • Biceps tendinitis.
  • Various types of tendon ruptures.
• Widespread (diffuse) non-inflammatory damage to the shoulder joint capsule – capsulitis
• Complex damage to the periarticular system – subacromial syndrome.

A detailed description of the causes of pain in the shoulder muscles.

• Tendinitis is an acute or chronic inflammation of the tendons surrounding the shoulder joint. Damage to the tendon inevitably entails pain in the shoulder muscles due to the close anatomical relationship of these structures. Tendinitis can affect both the rotator cuff muscle and the biceps, supraspinatus, infraspinatus, and subscapularis muscles. In addition, there is calcific tendonitis, in which calcifications accumulate in the tendon tissue.
• Inflammation of the tendon of the inner shoulder, flexor muscle, biceps tendonitis. The pain is intense, constant, and intensifies with arm movement.
• Inflammation of the joint – bursitis. The disease is closely related to overexertion and sports injuries. In addition to the painful symptom, bursitis is manifested by swelling in the bursa area, often the pain radiates to the arm, limiting the range of movements.
• Frozen shoulder syndrome or retractile capsulitis. This is a syndrome of reflex dystrophic damage to the shoulder joint capsule with parallel damage to bone structures in the form of osteoporosis.
• Humeroscapular periarthrosis is a syndrome that is still being actively studied, since its true etiology is not clear. In addition, the nature of pain in glenohumeral periarthrosis can vary from acute, intensifying pain to aching, constant pain. The pain does not subside with rest, may be accompanied by insomnia, and noticeably limits arm movements.
• Myofascial pain syndrome is a typical disease of muscle tissue in various areas of the body, but the favorite location for MFPS is the shoulder girdle and lower back. Myalgia, which accompanies tense muscles, develops in clearly defined places – trigger points.
• Vertebrogenic causes of pain in the shoulder muscles most often lie in osteochondrosis of the cervical spine, when a secondary complication develops – radiculopathy. It is believed that osteochondrosis may be one of the factors provoking glenohumeral periarthritis, periarthrosis.

Also, pain in the muscles of the shoulder girdle can be caused by the following syndromes and diseases:

Since a painful muscle symptom is most often not acute in nature, it is not always possible to identify its causes in a timely manner. More often, a patient consults a doctor with an already formed chronic pain syndrome and many accompanying reactions and signs, which significantly complicates the diagnosis of muscle pain in the shoulder girdle.

Symptoms of pain in the shoulder muscles

Pain in the shoulder girdle can have dozens of different causes; accordingly, the symptoms of pain in the shoulder muscles can be variable depending on the etiology and pathogenetic mechanism of development. The most significant and most common pain in the shoulder is nociceptive, which in turn is accompanied by many side signs and reactions. In addition, the nociceptive nature of the symptom allows you to trigger a cascade of psychosomatic, psychogenic sensations, which makes quick diagnosis and the possibility of pain relief extremely difficult. It is believed that in 65-70% of cases pain develops slowly, gradually as a reflex tonic response to systematic overstrain of the muscles of the shoulder girdle. The load on the shoulders can be either dynamic or static; in any case, muscle hypertonicity is accompanied by constant aching sensations that do not subside at rest and even at night.

Symptoms of pain in the shoulder muscles can be localized in areas of damage to the tendons, joints, ligaments, but can also be diffuse, fibromyalgia, myofascial syndrome.

How to identify the damaged area? Pain and limitation of arm movement

What can become inflamed or damaged?

• Pain when moving one or both arms back
• Damage to the subacromial bursa, inflammation in the supraspinatus muscle, in the tendon (inflammation, tendon sprain)
• Shoulders hurt when both arms are fully raised vertically
• Inflammation, degenerative change of the acromioclavicular joint and damage to the surrounding muscles
• Pain when trying to comb your hair, put your arms behind your head, or when externally rotating your arms
• Strain of the teres minor or infraspinatus tendon
• Aching pain when placing your arm behind your back
• Sprained or inflamed subscapularis tendon
• Painful symptom when bending the arm at the elbow and when lifting loads, turning the hand – the key is in the door (shoulder supination)
• Strain, inflammation of the biceps brachii muscle, tendon
• Pain when moving your arm behind your back (removing an object from your back pocket)
• Pain with shoulder internal rotation
• Damage (stretch, inflammation) of the subscapularis muscle of the shoulder
• All hand movements, head turns, neck movements cause pain, movements are severely limited
• Inflammatory process in the capsule of the shoulder joint, in the periarticular tissues.

Diagnosis of pain in the shoulder muscles

Diagnosis of pain in the shoulder muscles can be accurate provided:

• Specific location of pain.
• Onset of pain and diagnosis in the initial period of development of the syndrome.
• The absence or presence of specific signs accompanying muscle pain.

Diagnosis of pain in the shoulder muscles may include the following steps:

• Examination of a patient with shoulder pain.
• Determination of the symmetry of the location of the shoulder blades, arms, and collarbones (with paresis, the lowering of the shoulder on the affected side is clearly visible).
• Visual identification, palpation examination of muscles for the presence of hypotrophied areas. Muscle wasting is especially characteristic during a long-term neurogenic process (more than 14 days).
• Tests to determine possible paresis.
• Tests that reveal balance and the ratio of active and passive movements.
• Test to determine resistance strength, function of the large and small muscles of the chest, muscles of the shoulder girdle.
• Determination of the strength of flexor and extensor muscles.
• Identification of symptoms similar to those of radicular syndrome.
• Assessment and determination of tendon reflexes.
• Palpation of radicular exit points, identifying signs of radicular damage.
• Identification of diagnostically important trigger points for confirmation of fibromyalgia, MFPS (myofascial pain syndrome).

Also, to specify diagnostic conclusions, an X-ray of the spine (cervical-brachial, thoracic area) can be prescribed; neuroimaging methods can be used – MRI, CT, ultrasound of joints, as well as Dopplerography of blood vessels and electrophysiological examinations to determine muscle tone

How to distinguish joint and muscle pain in the shoulder girdle

Diagnostic signs of various pains.

Joint pathologies

Characteristics of the pain symptom of joint pain

• The pain is constant, does not subside with rest, and slightly intensifies with movement.
• Pain develops in response to a specific movement
• Shoulder pain localization area
• The pain is often diffuse and diffuse
• The pain is clearly localized and has boundaries
• Dependence on active or passive movements
• Significant restriction of the volume of all types of movement
• Reducing the volume of active and simultaneous preservation of all types of passive movements without changes
• Presence or absence of edema
• Often swelling is visible to the naked eye, effusion is detected

Muscle tissue diseases (periarticular structures)

Muscle pain often provokes body asymmetry, and is also characterized by swelling in the joint area due to bursitis

Treatment of pain in the shoulder muscles

The general rules that apply to the treatment of pain in the shoulder muscles are very similar to the stages and methods of treating diseases of the joints and musculoskeletal system.

Treatment of muscle pain in the shoulder girdle:

• Neutralization of all pain-provoking factors – immobilization of the arm, shoulder, often complete rest.
• Anti-inflammatory drugs – non-steroidal anti-inflammatory drugs (NSAIDs) in tablet form, as well as in the form of ointments and gels.
• Pain relief with compresses (30% dimexide solution).
• Injections of corticosteroids into the affected area may be possible.
• Periarticular administration of homeopathic medicines – Traumeel, Zeel.
• Activation of trophism of periarticular tissues, improvement of metabolic processes with the help of physiotherapeutic procedures.
• Purpose of a complex containing B vitamins and microelements.
• Muscle massage, including massage with joint development.

As a rule, therapy for mild muscle pain that develops as a result of muscle strain does not last more than 3-5 days. Reasonable rest, adjustments to training exercises and a gentle, warming massage are quite enough. Other cases require complex diagnostics, often a dynamic examination (monitoring the condition of the shoulder girdle in motion) and the prescription of a course of drugs that reduce the perception of pain, improve the trophism of muscle fibers, and neutralize inflammation.

Preventing pain in the shoulder muscles

Preventive measures aimed at getting rid of pain in the shoulder girdle, first of all, depend on the cause and the identified provoking factor. Basically, the prevention of pain in the shoulder muscles is a system of exercises designed for athletes whose shoulder girdle is actively involved. The following rules for strengthening the “corset” of periarticular tissues also help reduce the risk of developing muscle pain in the shoulder:

• It is necessary to ensure proper hardness of the bed, sleep on a small pillow.
• Warm up all muscles daily, including the muscles and tendons of the shoulder.
• At the slightest painful symptoms in the shoulder, you should limit the movement of the arm on the side of pain and give them a little rest.
• If a person performs monotonous, rhythmic movements with his hands as part of his job (a painter, a conveyor line operator, etc.), he should regularly massage the shoulder area, possibly using essential oils, warming and relaxing gels.
• All exercises from the physical therapy complex should not be performed intensively and for a long time; exercises should not exceed 15-20 minutes in the morning and no more than 30 minutes throughout the day (2-3 approaches, each 15 minutes).

Pain in the shoulder muscles is a very common symptom inherent in our age of speed and physical inactivity. Unfortunately, shoulder symptoms provoked by physical exercise do not exceed 25-30% of all cases; they are based on overstrain of the shoulder muscles as a result of prolonged static posture, hypothermia and atony, and muscle weakness. That is why strengthening the muscle corset, maintaining the normal state of the muscles, following the regime – tone-relaxation, this is the way to avoid discomfort in the shoulder girdle.