Shoulder anatomy

Shoulder anatomy . It is not a single joint , but a joint complex , where several joints work in coordination to allow a wide range of very wide movements and in many directions. The anatomical region of the shoulder is made up of the union of three bones : humerus , scapula, and clavicle .


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  • 1 Anatomy of the shoulder
  • 2 Shoulder muscles and tendons
  • 3 Vascular and nervous structures
  • 4 Rotating Muscle
  • 5 common shoulder injuries
  • 6 Treatment of shoulder injuries
  • 7 Sources

Shoulder anatomy

The scapula, shoulder blade or, in popular language, the shoulder blade , is a flat, triangular-shaped bone that adapts to the back of the chest and advances forward through an extension or process , the acromion , to search for the clavicle. , forming the acromio-clavicular joint . In its outermost part and below the acromion, is the glenoid cavity . In the humerus, in addition to the head , almost spherical in shape, we must mention two bony protuberances, the greater trochter or tuberosity and the troquinor minor tuberosity, and a cleft, the bicipital slide , through which the long portion of the biceps tendon slides . The clavicle, the third of the region’s bones, is shaped like that italic . It is an elongated, horizontal bone that extends from the sternum to the acromion , bones with which it forms the sterno-clavicular and acromio-clavicular joints . In the conjunction of the shoulder bones, we have seen, therefore, that two joints and a space are formed:

If the supporting ligaments are torn, acromio-clavicular sprains occur. The clavicle rises and produces a deformity in the shoulder, functionally tolerable but not very aesthetic. The subacromial space, between the acromion and the head of the humerus, is a very important cavity since it circulates, slides, a group of tendons essential for lifting and rotating the arm , the so-called rotator cuff . Injury to these tendons, especially the so-called supraspinatus tendon , is the source of discomfort, sometimes very intense, which requires prolonged treatment, including surgical treatment. The gleno-humeral jointIt features some soft tissue structures that surgeons have learned to understand much better from arthroscopic imaging . Inside we can see two tendons, a long portion of the biceps and subscapularis , the articular capsule that presents three thickened areas that we call the gleno-humeral ligaments (anterior, middle and inferior) and the labrum, a ring that borders the glenoid cavity , which it is joined, and in which capsule and gleno-humeral ligaments are inserted .

Shoulder muscles and tendons

The rotator cuff is made up of the tendons of the supraspinatus , infraspinatus , subscapularis, and minor round muscles . The set of these four tendons forms a coping , which surrounds and covers the head of the humerus , starting from the trocheter and extending below the acromion to the space above the spine of the scapula . The most important joint mission of these muscles is abduction and rotation of the shoulder. Other muscles that connect the scapula to the arm are the deltoid, a large muscle mass that forms the external relief of the shoulder, the coraco-brachialis, and the lesser round. Muscles that join the scapula to the chest are: major and minor rhomboids , serratus and trapezius behind and pectoralis minor in front. Joining chest and arm, pectoralis major and latissimus dorsi .

Vascular and nervous structures

The most important is the brachial plexus , a cluster of nerve connections formed by the roots that arise from the spinal cord in its cervical portion, which is protected in the armpit , and which end up differentiating into the three most important nerves of the arm, the radial , ulnar and medium. In the posterior part of the scapula, we must mention the infrascapular nerve , whose injury produces a very striking atrophy of the posterior scapula muscles. The most important artery is the humeral artery , which will give rise to the radial and ulnar arteries . It runs parallel to the nerves that start from the brachial plexusand it is a branch of the axillary artery, which in turn is a branch of the subclavian artery , which, as its name suggests, circulates below the clavicle. To each artery there corresponds a venous circulation of blood return but, in addition to the humeral vein, we have to mention the basilic vein and the cephalic vein .

Rotating muscle

The head of the humerus is held in the hollow or glena by the joint capsule and ligaments and by four muscles and their tendons . The union of all these elements is what is called the muscle or rotary fist . This group of tendons fuse together and surround the front, back, and top of the shoulder joint . They connect the muscles that originate in the shoulder blade . When these muscles contract, they cause the rotary muscle tendon to rotate inward, outward, or upward. The rotator cuff As it is commonly called, it has an important function of stabilizing the shoulder, as well as raising and rotating the arm.

Common shoulder injuries

The shoulder joint can be associated with a ball in a baseball glove and this is the reason why the joint is so mobile, making it the most mobile in the human body. As a result of this freedom of movement, the shoulder is a susceptible site for injury in many ways. Repetitive movements put muscles and ligaments in a vulnerable position. Hence, many of the shoulder injuries occur in people with forced labor that require constant and repeated movements with the shoulder.

Most shoulder injuries are treated conservatively with rest and physical therapy . However, there are other alterations in this joint that require surgical intervention.

  • Cervicobrachialgias
  • Frozen Shoulderor Adhesive Capsulitis
  • Biceps tendinosis
  • Subacromial bursitis
  • Tear of the biceps tendon
  • Rupture of the rotator cuff

Treatment of shoulder injuries

The treatment of a problem at the shoulder level is very varied, therefore, in physical therapy there are multiple useful and effective non-invasive treatment methods to achieve maximum recovery. Rest is very important in cases of glenohumeral injury , always focused not on the whole but on avoiding movements that cause pain.

The cryotherapy (cold temperature treatments) to reduce pain, reduce inflammation and reduce edema and swelling is equally necessary mainly in acute stages.

Hot media treatment helps improve relaxation and muscle relaxation . It is essential that some hot medium is used, such as a hot-wet compress, paraffin or gel compresses, prior to mobilization. Mobilization is another method that can not be missed in the rehabilitation of a shoulder problem. Electrotherapeutic agents such as:

  • Microcurrents
  • To be
  • Ultrasound
  • Interferential

Stretching and strengthening exercises should be applied until improvement in joint condition and pain is noted.


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