Shoulder pain and posture: how biomechanics influences discomfort

Shoulder pain is a frequent complaint and can arise at different ages and in various contexts. In many cases, it can be related to how the body organises itself and moves on a daily basis. Posture and movement habits influence how loads are distributed across the shoulder joints and muscles, and when these patterns are maintained over time, they can be associated with discomfort, stiffness, or functional limitation.

It is important to mention that posture, in itself, does not always explain all pain. However, remaining for long periods in unchanging positions can favour tissue adaptations and altered shoulder biomechanics, making the region potentially more sensitive to exertion or repetitive movement.

Shoulder biomechanics: shoulder blade, thoracic spine and movement control

The shoulder is a joint with a large range of motion, and its function depends on the coordination between various structures. Besides the glenohumeral joint, efficient shoulder movement involves the shoulder blade (or scapula), the collarbone, and the thoracic spine, in a set of interactions often described as the scapulohumeral rhythm.

The scapula plays a significant role in the stability and orientation of the shoulder during arm movement. Its position and mobility can influence how the shoulder joint distributes loads, particularly in overhead movements or repetitive tasks. For this process to occur efficiently, adequate thoracic spine mobility and functional muscular control of the scapular region are generally important.

When there are changes in thoracic spine mobility, excessive stiffness, or less efficient muscle control patterns, scapular positioning can be modified. In these situations, the shoulder may be loaded in a less favourable way, which over time can increase the demands on muscles, tendons and joint structures.

How postural changes can influence shoulder function

The functioning of the shoulder depends on effective coordination between arm movement and scapular movement, the bone that connects the shoulder to the torso. When posture changes persistently, such as in situations of protracted shoulders, increased dorsal curvature, or reduced thoracic spine mobility, this coordination can be affected.

These changes may be associated with:

• Reduced efficiency of the muscles contributing to shoulder stability
• Increased tension in the more superficial muscles
• Reduced thoracic spine mobility, relevant for arm elevation
• Increased load on tendons and periarticular tissues

Over time, these patterns can be associated with pain, stiffness, or a feeling of weakness, particularly in people with sedentary jobs, repetitive tasks, or frequent overhead exertion.

Clinical assessment allows us to analyse how posture and movement patterns relate to the symptoms presented, helping to guide strategies that promote more efficient movement organisation and a more balanced distribution of loads.

Practical strategies to improve posture and support shoulder pain prevention

Some simple everyday strategies can contribute to better postural organisation and more appropriate management of the loads placed on the shoulder, especially when applied progressively and adjusted to each person's characteristics.

• Posture awareness Paying attention to your posture throughout the day can help identify positions held for prolonged periods, such as shoulders slouched forward or the head pushed forward. Recognising these patterns can make small adjustments easier, which tend to reduce the strain on certain structures.
• Strength training strengthening of the dorsal musculature, shoulders and colour, responsible for trunk stability, contributing to a more balanced posture. Greater proximal stability tends to favour more efficient use of the shoulder in daily and work activities.
• Mobility and stretching: Regular mobility exercises and stretches can help to reduce muscle tension and maintain range of motion, especially in muscles that tend to become shorter in contexts of sustained postures or repetitive movements.
• Ergonomics in daily activities: Small adjustments to the workstation and the way daily tasks are performed can contribute to a more suitable distribution of stress on the shoulder. When maintained over time, these adaptations can impact comfort and joint function.

These guidelines should always be contextualised. When shoulder pain is persistent, recurring or affects function, an assessment by an Osteopath or Physiotherapist can help to understand the factors involved and to guide these strategies more safely and appropriately.

When to seek clinical assessment for shoulder pain

It may be advisable to seek assessment when there is:

• Persistent or recurrent pain
• Difficulty lifting or twisting the arm
• At night or while sleeping on the shoulder
• Feeling of loss of strength or control of the arm
• Pain that extends to the neck or arm

These signs help to guide clinical assessment and to better understand the factors involved in each case.

Understanding shoulder pain integratively

In many cases, shoulder pain results from a combination of factors, such as biomechanics, load, recovery, and life context. A clinical assessment allows for the identification of which of these elements may be most relevant for each individual and guides a tailored approach, focusing on function, comfort, and adaptation over time.