The Shoulder and Shoulder Pain

The Shoulder: A Complex Structure Designed for Movement 

The shoulder is one of the most mobile regions of the human body. Thanks to it, we can perform movements such as raising the arm, reaching for objects, pushing, carrying weight, or executing precise movements with the hand. 

However, this great capacity for movement depends on a highly precise balance between mobility, stability, and coordination. 

Unlike other more stable joints in the body, the shoulder must allow for a wide range of motion, which is why it relies on a highly coordinated muscular and articular system. 

The Shoulder Is Not Just a Single Joint 

When we talk about the shoulder, we are not referring solely to the connection between the head of the humerus and the scapula. There is actually a complex of structures working together as a functional unit: 

• Glenohumeral joint (humerus and scapula) 

• Scapula (shoulder blade) 

• Clavicle (collarbone) 

• Acromioclavicular joint (acromion and clavicle) 

• Thoracic spine 

• Rib cage 

• Stabilizing muscles 

This entire system allows the arm to move while maintaining its stability.

 The Importance of the Scapula: The Foundation of Shoulder Movement 

The scapula plays a fundamental role because it acts as a mobile platform from which the arm can move. 

For the shoulder to function correctly, the scapula must accompany every movement of the arm through precise coordination. 

Muscles involved in this process include: 

• Upper, middle, and lower trapezius 

• Rhomboids

• Serratus anterior 

• Levator scapulae 

These muscles do not just generate strength; they also maintain the proper position of the scapula so that movement is efficient. 

When the scapula loses mobility or motor control, the shoulder may begin to compensate. 

The Connection Between the Scapula, Thoracic Spine, and Shoulder 

The scapula does not float independently. It is directly connected to the thoracic spine, the ribs, and various muscle groups. 

Therefore, an alteration in one area can modify the function of another. 

For example:

• A thoracic spine with limited mobility can restrict the movement of the scapula. • A scapula with poor motor control can increase the load on the shoulder. 

• Weak or overloaded posterior musculature can alter the positioning of the arm.

The body works as an interconnected system, not as separate parts.

Shoulder Pain 

Shoulder pain can arise from various causes, and it does not always mean the problem lies solely within the joint itself. 

The shoulder receives mechanical inputs and loads from many structures working together, which is why it is essential to assess the entire kinetic chain. 

It may be related to: 

• Alterations in scapular movement (scapular dyskinesis)

• Muscle overload 

• Thoracic mobility restrictions 

• Rotator cuff tendons 

• Biceps tendon 

• Joint stiffness 

• Lack of muscle control 

• Nervous system sensitization

Different Pain Patterns and Their Potential Connections 

Anterior Shoulder Pain 

The anterior zone is typically related to structures such as: 

• Biceps tendon 

• Anterior aspect of the rotator cuff (supraspinatus, infraspinatus, teres minor, and subscapularis) • Periarticular tissues. 

However, there can also be influence from the posterior aspect of the body. 

A scapula that lacks proper stability can increase the mechanical demand on the anterior shoulder. Additionally, persistent tension in posterior muscles like the rhomboids and trapezius can cause referred pain to the front. 

Lateral Shoulder Pain 

Lateral discomfort frequently occurs with movements such as raising the arm. 

It may be related to: 

• Rotator cuff overload 

• Altered scapulohumeral rhythm 

• Tissue irritation within the subacromial space 

Here, it is crucial to analyze how the entire system moves, not just the painful structure. 

Posterior Shoulder Pain 

Posterior pain can be related to: 

• Overload of the stabilizing muscles 

• Scapular tension and stiffness 

• Lack of thoracic mobility 

• Altered movement control 

Often, this area works constantly to keep the shoulder stable and ends up accumulating tension.

The Nervous System and Shoulder Pain 

Pain does not depend solely on muscles or joints.

The nervous system regulates how we interpret bodily signals and can increase sensitivity when there is: 

• Persistent pain 

• Physical or emotional stress 

• Lack of rest 

• Repetitive overload 

When the body remains in a state of high alert for extended periods, it can increase muscle tension and modify the way we move (often unconsciously). 

The Connection Between Stress, Emotions, and the Shoulders 

The shoulders are an area where many people accumulate tension. 

When prolonged stress is present, it can trigger: 

• Constant activation of the trapezius muscle 

• Involuntary and subconscious elevation of the shoulders 

• Cervical stiffness 

• Alteration of breathing patterns

• Increased scapular tension (due to long static periods) 

This happens because the nervous system directly influences muscle tone and the way the body responds to daily physical demands. 

Therapeutic Approach in Physiotherapy 

Shoulder treatment must aim to restore the function of the entire system. 

It may include: 

1. Manual therapy 

2. Myofascial release 

3. Deep dry needling 

4. Scapular rehabilitation 

5. Techniques such as EPTE/percutaneous electrolysis 

6. Pain neuroscience education 

7. Therapeutic Exercise