The acromioclavicular (AC) joint is a small but vital joint in the shoulder that plays a crucial role in arm movement and stability. When this joint becomes irritated or injured, it can lead to AC joint dysfunction, causing pain, restricted movement, and discomfort in everyday activities.

In this article, we’ll explore what AC joint dysfunction is, how it happens, what it feels like, and how osteopathy can help restore function and relieve pain.

What Is the AC Joint?

The AC joint is located at the top of the shoulder where the clavicle (collarbone) meets the acromion, a bony part of the scapula (shoulder blade). It is a small but essential joint that allows the arm to move overhead and across the body.

The joint is stabilized by ligaments that keep the bones in place and absorb forces from movements. A cartilage disc sits between the bones to help with shock absorption and smooth movement. However, due to its location and function, the AC joint is vulnerable to injuries and wear and tear.

How Does AC Joint Dysfunction Happen?

There are several ways AC joint dysfunction can occur, including trauma, repetitive strain, and degenerative changes.

1. Traumatic Injuries

A sudden injury, such as a fall onto the shoulder, a direct blow, or an accident, can cause damage to the AC joint. This is common in contact sports like rugby, football, or martial arts.

A severe injury can lead to an AC joint separation, where the ligaments are stretched or torn, leading to instability and noticeable deformity at the top of the shoulder.

2. Repetitive Overuse

Repeated stress on the AC joint can lead to irritation and inflammation over time. This often occurs in people who perform overhead movements frequently, such as weightlifters, swimmers, or construction workers.

Movements like pressing weights, throwing, or repetitive overhead lifting can strain the AC joint, leading to gradual wear and dysfunction.

3. Osteoarthritis and Degeneration

Like other joints in the body, the AC joint is prone to degeneration as we age. The cartilage that cushions the joint can wear down over time, leading to osteoarthritis.

This can cause pain, stiffness, and inflammation, particularly when moving the shoulder. AC joint osteoarthritis is common in people over 50 and in those who have had previous shoulder injuries.

4. Poor Posture and Muscle Imbalances

Rounded shoulders, poor posture, or muscular imbalances in the upper body can put extra strain on the AC joint. If the surrounding muscles are weak or tight, they can fail to properly support the shoulder, leading to excessive pressure on the AC joint.

Office workers, cyclists, and individuals who spend long hours hunched over screens are at higher risk of developing postural-related AC joint dysfunction.

What Does AC Joint Dysfunction Feel Like?

Symptoms of AC joint dysfunction can vary depending on the cause and severity of the condition. Some of the most common symptoms include:

1. Pain at the Top of the Shoulder

Pain is often felt directly over the AC joint, especially when pressing on the area. The pain may be sharp with movement or dull and aching at rest.

2. Pain with Overhead Movements

Activities that involve raising the arm above the head, such as reaching for a shelf, throwing, or lifting weights, can trigger pain.

3. Pain When Lying on the Affected Side

Sleeping on the affected shoulder can cause discomfort and worsen symptoms. Many people with AC joint dysfunction struggle to find a comfortable sleeping position.

4. Swelling and Tenderness

The AC joint may appear slightly swollen or tender to the touch, particularly after activity or injury.

5. Limited Range of Motion

There may be stiffness or difficulty moving the shoulder, particularly in movements that involve crossing the arm over the body or reaching behind the back.

6. Clicking or Popping Sensation

Some individuals experience clicking, popping, or grinding noises when moving their shoulder due to cartilage wear or ligament laxity.

7. Weakness in the Shoulder

Weakness or instability in the shoulder can make it difficult to perform daily activities such as lifting objects, getting dressed, or carrying bags.

How Can an Osteopath Help with AC Joint Dysfunction?

Osteopathy is a holistic and hands-on approach to treating musculoskeletal conditions, including AC joint dysfunction. An osteopath will assess the underlying causes of pain and dysfunction, considering factors such as posture, movement patterns, and muscle imbalances.

1. Comprehensive Assessment

An osteopath will begin by taking a thorough case history and performing a physical examination. This may involve assessing shoulder mobility, posture, muscle strength, and any compensatory movement patterns that may be contributing to the issue.

If necessary, they may refer for imaging (such as X-rays or MRI scans) to rule out fractures or severe ligament damage.

2. Hands-On Treatment Techniques

Osteopaths use a variety of manual therapy techniques to restore movement and relieve pain, including:

• Soft Tissue Massage: Helps to release tight muscles and reduce tension around the shoulder.
• Joint Mobilization: Gently improves movement and reduces stiffness in the AC joint and surrounding structures.
• Myofascial Release: Targets fascial restrictions that may be limiting mobility or causing pain.
• Stretching and Muscle Energy Techniques: Improve flexibility and restore muscle balance.

3. Addressing Postural Issues

If poor posture is contributing to AC joint dysfunction, an osteopath can provide advice on ergonomic adjustments, posture correction exercises, and ways to reduce strain on the shoulder in daily activities.

For example, strengthening the mid-back and core muscles can help take pressure off the AC joint and improve overall shoulder function.

4. Rehabilitation Exercises

Rehabilitation exercises are a crucial part of recovery. An osteopath may prescribe:

• Strengthening exercises: To build stability in the shoulder and surrounding muscles.
• Stretching exercises: To maintain mobility and prevent stiffness.
• Proprioception exercises: To improve joint awareness and reduce the risk of future injury.

These exercises will be tailored to your specific condition and lifestyle needs.

5. Lifestyle and Activity Modifications

An osteopath can guide you on modifying activities to prevent aggravating the AC joint. This may include adjusting workout techniques, modifying work-related movements, or recommending supportive braces during high-impact activities.

6. Pain Management Strategies

For acute cases, osteopaths may use gentle techniques to reduce inflammation and pain. They can also advise on pain-relief strategies such as ice therapy, heat applications, or dietary approaches to reduce inflammation.

When to Seek Osteopathic Care for AC Joint Dysfunction

If you experience persistent shoulder pain, restricted movement, or difficulty performing daily activities due to AC joint dysfunction, seeking osteopathic care can be beneficial. Early intervention can prevent symptoms from worsening and improve long-term function.

At Thrive Body Clinic, we take a whole-body approach to your well-being. Whether your AC joint dysfunction is due to injury, overuse, or posture-related strain, our osteopathic treatments can help restore pain-free movement and improve shoulder health.

If you’re struggling with shoulder pain, book an appointment today and let us help you get back to doing what you love!