Palpation is the act of feeling anatomical structures with the hands and is a foundational skill in physical assessment. The coracoid process of the scapula is a significant, deep-seated bony landmark on the anterior shoulder. Accurately locating this structure is important for identifying muscle and ligament attachment points, guiding diagnosis and therapeutic interventions. This small projection can be challenging to find, especially in individuals with developed musculature, requiring a precise technique for correct physical examination.
Anatomical Context of the Coracoid Process
The coracoid process is a thick, hook-shaped projection arising from the upper, front part of the scapula. It is situated directly inferior to the lateral end of the clavicle and points forward and slightly laterally toward the shoulder joint. This location places it deep within the soft tissues of the anterior shoulder, serving as an attachment site for three muscles: the Pectoralis minor, the Coracobrachialis, and the short head of the Biceps Brachii.
The process lies within the deltopectoral groove, the shallow depression between the deltoid and the Pectoralis major muscles. Its position is relatively fixed compared to the surrounding mobile structures of the shoulder complex.
Preparing the Subject for Palpation
To optimize palpation, the subject should be positioned to encourage maximal relaxation of the overlying musculature. The subject can be comfortably seated or supine with their arm resting naturally at their side. This relaxed posture softens the Pectoralis major and the anterior fibers of the deltoid, which can otherwise obscure the landmark.
The arm should be supported and positioned in a neutral or slightly adducted and extended position to reduce tension in the Biceps Brachii and Pectoralis minor muscles. This slackening allows the examiner to more easily press through the soft tissue layers to reach the bony projection. Subject comfort is important, as involuntary tensing of the shoulder muscles increases the difficulty of palpation.
Executing the Palpation Technique
Palpation begins by locating the lateral two-thirds of the clavicle, following its curvature toward the shoulder. Identify the point where the clavicle meets the acromion process. From this junction, move your finger approximately 2 to 3 centimeters directly inferiorly into the soft tissue.
You will typically land within the deltopectoral groove. Apply gentle but firm pressure, directing your finger slightly posteriorly and medially through the muscle fibers. The goal is to press the soft tissues against the underlying bone.
Continue to explore this area with small, circular motions until a distinct, hard, rounded bony knob is felt. This projection is the apex of the coracoid process. The depth required to feel the process will vary significantly depending on the subject’s body habitus and muscle tone.
Confirming Accurate Identification
Once a bony structure is located, it is necessary to verify that it is the coracoid process and not the adjacent humeral head, which is a common error. The definitive way to differentiate the two structures is through movement testing. The coracoid process is part of the scapula, which acts as a stable anchor point during small shoulder movements.
Maintain firm contact on the identified bony structure with your palpating finger. Gently and passively rotate the subject’s arm internally and externally at the shoulder joint. If the bony structure is the coracoid process, it will remain stationary under your finger. If the structure moves or rolls under your finger, you are likely on the head of the humerus.