Shoulder blade

Shoulder Blade

The shoulder blade, also known as the scapula, is a triangular, flat bone that resides in the upper back, connecting the humerus (upper arm bone) to the clavicle (collarbone). It plays a crucial role in the human skeletal system, providing a foundation for the complex movements of the shoulder.

Anatomy

The shoulder blade is characterized by its unique triangular shape. It consists of several important parts, including the spine of the scapula, acromion, coracoid process, glenoid cavity, and subscapular fossa.

The spine of the scapula is a prominent ridge that runs diagonally across the back of the shoulder blade, dividing it into two regions: the supraspinous fossa and the infraspinous fossa.

The acromion is a bony projection off the spine of the scapula and forms the highest point of the shoulder. It connects with the clavicle to form the acromioclavicular joint.

The coracoid process is a small hook-like structure on the lateral edge of the superior anterior part of the scapula.

The glenoid cavity is a shallow, articular surface, which is located on the lateral angle of the scapula. It articulates with the head of the humerus to form the glenohumeral joint, also known as the shoulder joint.

The subscapular fossa is a broad concavity on the costal surface of the scapula.

Function

The shoulder blade serves multiple functions in the human body. It forms the socket part of the shoulder joint, allowing for a wide range of motion. It also provides attachment points for many muscles, including the rotator cuff muscles, which are essential for shoulder stability and movement.

Clinical Significance

Conditions affecting the shoulder blade include fractures, winging and snapping scapula syndrome.

Fractures of the scapula are relatively rare and usually result from high-energy trauma.

Winging is a condition where the shoulder blade protrudes from a person's back in an abnormal position.

Snapping scapula syndrome is characterized by a cracking sound or sensation in the scapula area, often accompanied by pain.

See Also

• Human skeleton
• Shoulder joint
• Rotator cuff