Hello and welcome to Aula Fisio.
In today's video I would like to talk to you in depth about one of the pathological disorders of the shoulder that we most frequently see in clinical practice.
It is the Syndrome of Impingement or Subacromial Impingement (SIS). This one accounts for almost half
of all the medical consultations that come for shoulder pain.
BUT ... WHAT IS IT EXACTLY AND WHAT DOES IT CONSIST OF?
For a long time it was considered as a diagnosis, but nowadays, the idea of framing it as a set of symptoms or pathological condition is more accepted.
It was mentioned in the first instance by Codman, who called it subacromial syndrome. Later, in 1972, Neer introduced the term Impingement or Impingement, in order to clarify the existence of an entrapment or compression.
We could define it then as a pathological friction or pinch of the soft tissues that have been included in the subacromial space.
This space is located between the head of the humerus and the coracoacromial arch, and it contains the rotator cuff tendons, the serous pockets (responsible for reducing friction during arm movements) and the tendon sheath of the long portion of the biceps brachial.
These elements will be those that are compromised in the Impingement Syndrome.
WHY IS IT PRODUCED?
SIS can be due to intrinsic or extrinsic causes. These factors can manifest themselves individually or simultaneously.
The intrinsic causes are the following:
- Vascular causes.
Because the Supraspinatus muscle tendon has a zone of low blood supply called the "Critical Zone" located approximately 1 cm from its insertion.
- Degenerative Causes
In which we will find the presence of osteophytes in the acromion.
- Anatomic Causes
Due to the shape of the acromion. Being type III or "hooked" the form most closely related to the pathology of the rotator cuff.
- Mechanical Causes.
Because during flexion and separation of the arm, the greatest impact of the humeral head occurs in the subacromial space.
And finally,
- Traumatic Causes
Due to a fall or direct trauma.
We will now talk about extrinsic causes.
- The alteration of the Scapular Kinematics. That is, a deficit in the lateral chime movement of the scapula resulting in a reduction of the subacromial space during arm movements.
- Postural causes that will modify all the correct biomechanics of the shoulder joint complex.
CLASSIFICATION
The SIS were classified by Neer in three stages according to age and the state of deterioration of the tendon structures.
In the first stage there is the presence of inflammation and edema of the serous pockets and tendons. It appears as a consequence of repetitive professional or sports microtrauma. And it is usually related to subjects under the age of 25
The second stage is characterized by the appearance of fibrosis in the serous pockets and micro tears in the tendon. It is related to ages between 25 and 40 years.
Finally, the third stage is characterized by the presence of a partial or total rupture of the rotator cuff associated with bone modifications due to degenerative causes. The related age in this case is over 40 years.
If we attend to the area where the clamping will take place, we can classify it in two ways: internal and external.
In the External or Subacromial, the Supraspinatus tendon is the most affected element. The mechanism that triggers pain occurs during Flexion, Adduction and Internal Rotation of the shoulder. A clear example of this position would be the one used by painters when using the roller.
In the Internal Impingement, the rotator cuff tendon is pinched between the humeral head and the glenoid impeller, which is a type of fibrocartilage that increases congruence between the articular surfaces of the shoulder.
Depending on the affected area, we can subdivide this Internal Impingement into Posterosuperior and Anteromedial.
The Anteromedial is characterized by affecting the subscapularis muscle tendon and its production mechanism is Flexion + Adduction + Internal Rotation.
The Posterosuperior affects the tendons of the infraspinatus and supraspinatus muscles, the production mechanism being Flexion + Abduction + External Rotation. It is very typical in throwing sports such as baseball, water polo, tennis, etc.
WHAT SYMPTOMS DOES IT PRESENT?
The SIS is characterized by:
- Pain located in the anterolateral area of the shoulder
- Mechanical pain, that is, when moving the arm.
- Night pain, especially if you sleep leaning on the affected shoulder.
21 авг 2024
