Palpation involves using touch to examine body parts, providing information about underlying structures. The acromioclavicular (AC) joint, located in the shoulder, is a common area for this examination. Proper palpation offers insight into its normal anatomy and potential changes.
Understanding the AC Joint
The acromioclavicular (AC) joint is a small but important articulation in the shoulder complex. It forms where the lateral end of the clavicle (collarbone) meets the acromion, which is a bony projection extending from the scapula (shoulder blade). The acromion forms the highest point of the shoulder. This joint provides stability and facilitates a wide range of shoulder movements.
Preparing for Palpation
Position yourself or the individual comfortably with good lighting. When touching the area, use the pads of your fingertips and apply only gentle pressure. This information is for educational purposes and not a substitute for professional medical advice. If you experience pain or suspect an injury, consult a healthcare professional.
Step-by-Step Palpation Guide
To begin palpating the AC joint, first locate the clavicle, the long bone running horizontally across the top of your chest. You can easily feel its entire length by tracing it from your sternum outwards towards your shoulder. As you move your fingers along the clavicle towards its outer end, you will notice it begins to flatten and widen slightly.
Continue tracing the clavicle laterally until it meets the acromion, the prominent bony process of the shoulder blade. As you gently glide your fingers from the clavicle onto the acromion, you should feel a slight dip or small step, indicating the joint line or space between the two bones. This subtle indentation marks the articulation of the clavicle with the acromion.
Once you have identified this joint line, use one or two fingertips to make small, gentle circular movements over the area. This technique allows you to explore the texture and contour of the joint more thoroughly. You can also try palpating both shoulders for comparison, noting any differences in feel or symmetry between the two sides. This comparison can help you understand what feels typical for your own body.
What You Might Feel and When to Seek Help
When palpating a healthy acromioclavicular joint, you should feel a smooth, firm bony surface with a slight indentation at the joint line. The area should not elicit any pain or tenderness. It should feel stable and consistent with the joint on the opposite shoulder.
However, if you experience significant tenderness directly over the joint, this could indicate an issue. Other signs that warrant attention include noticeable swelling, an increase in warmth around the joint, or a prominent bump or step-off deformity.
A feeling of instability or abnormal movement, sometimes described as a “piano key sign” where the clavicle can be pressed down and then springs back up, also suggests a potential problem. Pain radiating to the neck or other parts of the shoulder, especially with movement, can also be a symptom of an AC joint issue.
If any of these findings are present, or if you experience persistent pain or discomfort, it is important to consult a healthcare professional such as a doctor or physical therapist for a proper diagnosis and guidance. Self-palpation is a tool for awareness, not for self-diagnosis.