Infraspinous fossa

Infraspinatus fossa of left scapula- animation

Infraspinatus fossa - animation

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Infraspinatous fossa of scapula01

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Scapula post

Infraspinous fossa is a significant anatomical feature located on the scapula, or shoulder blade, which is a critical bone in the human skeleton. The infraspinous fossa is a concave surface that occupies the majority of the dorsal (posterior) aspect of the scapula, lying below the spine of the scapula. This area is of particular interest in the fields of anatomy, orthopedics, and physical therapy due to its role in shoulder movement and stability.

Anatomy

The infraspinous fossa is bounded superiorly by the spine of the scapula, a prominent ridge that divides the back side of the scapula into two distinct regions. The other region, located above the spine, is the supraspinous fossa. Inferiorly, the infraspinous fossa extends to the lower margin of the scapula. Laterally, it is bounded by the scapular neck and the glenoid cavity, which is the socket that articulates with the head of the humerus to form the shoulder joint.

The surface of the infraspinous fossa is covered by the infraspinatus muscle, one of the four muscles that make up the rotator cuff. This muscle originates in the infraspinous fossa and inserts on the greater tubercle of the humerus. The infraspinatus muscle is crucial for lateral rotation of the arm at the shoulder and plays a significant role in stabilizing the shoulder joint.

Function

The primary function of the infraspinous fossa is to serve as the origin site for the infraspinatus muscle. Through its muscular attachment, the fossa indirectly participates in the complex movements of the shoulder, particularly in external rotation and stabilization of the humeral head within the glenoid cavity. This stabilization is vital for a wide range of arm movements and is essential for preventing dislocation of the shoulder joint.

Clinical Significance

Injuries or conditions affecting the infraspinous fossa can lead to pain, weakness, and reduced range of motion in the shoulder. Conditions such as rotator cuff tears, shoulder impingement syndrome, and bursitis can directly impact the infraspinatus muscle and, by extension, the function of the infraspinous fossa. Diagnosis and treatment of such conditions often involve physical examination, imaging studies, and interventions ranging from physical therapy to surgical repair.

See Also

• Scapula
• Rotator cuff
• Shoulder joint
• Musculoskeletal system
• Orthopedic surgery