medial border of scapula

2 min read 16-03-2025

The scapula, or shoulder blade, is a flat, triangular bone located on the posterior aspect of the thorax. Its medial border, also known as the vertebral border, is a crucial anatomical structure with important functional implications. This article will delve into the anatomy, function, and clinical significance of the medial border of the scapula.

Anatomy of the Medial Border of the Scapula

The medial border of the scapula is the longest of its three borders. It runs vertically from the superior angle of the scapula to the inferior angle. This border is relatively straight and lies close to the vertebral column, hence its alternative name, the vertebral border. Several important landmarks are found along this border:

Key Landmarks:

Superior Angle: The point where the medial and superior borders meet.
Inferior Angle: The point where the medial and lateral borders meet. This is a palpable landmark.
Vertebral Border: The entire length of the medial border. This is where the muscles involved in scapular movement attach.

Muscles Attaching to the Medial Border

Several important muscles originate or insert along the medial border of the scapula, contributing to its complex movement and stability:

Rhomboid Major: This large muscle originates from the spinous processes of T2-T5 and inserts along the medial border of the scapula, inferior to the spine of the scapula. It retracts and rotates the scapula. [Link to article about rhomboid muscles]
Rhomboid Minor: Smaller than the rhomboid major, this muscle originates from the spinous processes of C7-T1 and inserts on the medial border of the scapula, superior to the spine. Like the rhomboid major, it retracts and rotates the scapula. [Link to article about rhomboid muscles]
Levator Scapulae: This muscle originates from the transverse processes of C1-C4 and inserts on the superior medial border of the scapula. It elevates the scapula. [Link to article about levator scapulae]

Function of the Medial Border

The medial border's primary function is to provide attachment points for muscles crucial for scapular movement. These movements are vital for a wide range of upper limb actions, including:

Scapular Retraction: Pulling the scapula towards the vertebral column. This is important for actions like pushing and rowing.
Scapular Protraction: Moving the scapula away from the vertebral column. This is involved in reaching forward.
Scapular Upward Rotation: Rotating the scapula upwards, crucial for arm abduction (lifting the arm overhead).
Scapular Downward Rotation: Rotating the scapula downwards.

Clinical Significance

Injuries or pathologies affecting the medial border of the scapula or the muscles attached to it can lead to various clinical problems:

Scapular Winging: This occurs when the medial border of the scapula protrudes from the back, often due to damage to the long thoracic nerve, which innervates the serratus anterior muscle. [Link to article about scapular winging]
Rhomboid Muscle Strain: Overuse or injury can cause pain and dysfunction in the rhomboid muscles, leading to limited scapular movement and pain along the medial border.
Levator Scapulae Syndrome: This condition involves pain and stiffness in the neck and upper back due to tightness or inflammation of the levator scapulae muscle.

Assessing the Medial Border

Palpating the medial border during a physical examination is crucial for assessing scapular positioning and potential abnormalities. Any asymmetry or unusual prominence of the border may indicate underlying issues.

Conclusion

The medial border of the scapula is a vital anatomical structure that plays a significant role in upper limb function. Understanding its anatomy, muscle attachments, and clinical relevance is crucial for healthcare professionals involved in the diagnosis and treatment of musculoskeletal disorders. Further research into the biomechanics of scapular movement is continuously expanding our understanding of this important region.