What Is The Medial Border Of The Highlighted Region Called

The medial border of the scapula, a long, vertebral edge that runs parallel to the spinal column, is also commonly referred to as the vertebral border. This important anatomical landmark serves as an attachment site for several muscles essential for shoulder movement and stability. Understanding its location, function, and the surrounding structures is crucial for healthcare professionals, athletes, and anyone interested in human anatomy and biomechanics.

Delving into the Scapula's Anatomy

The scapula, or shoulder blade, is a flat, triangular bone situated in the upper back. It plays a vital role in connecting the upper limb to the thorax. To fully appreciate the significance of the medial border, let's first outline the scapula's key features:

Body: The main, flattened part of the bone.
Spine: A prominent ridge on the posterior surface, leading to the acromion.
Acromion: A bony projection that articulates with the clavicle (collarbone), forming the acromioclavicular joint.
Glenoid Fossa: A shallow socket that articulates with the head of the humerus (upper arm bone), forming the glenohumeral joint (shoulder joint).
Lateral Border: The edge of the scapula that angles superiorly and laterally from the inferior angle to the glenoid fossa.
Superior Border: The shortest and thinnest border, located superior to the scapular spine.
Superior Angle: The corner formed by the junction of the superior and medial borders.
Inferior Angle: The corner formed by the junction of the medial and lateral borders.
Coracoid Process: A hook-like process projecting anteriorly from the superior border.

The medial border, our primary focus, extends from the superior angle down to the inferior angle. Its relatively straight course distinguishes it from the more angled lateral border.

Muscles Attaching to the Medial Border

The medial border of the scapula is a crucial attachment site for several muscles that control scapular movement and contribute to shoulder stability. These muscles include:

Serratus Anterior: While primarily attaching to the anterior surface of the scapula, the serratus anterior also has attachments along the medial border. Its primary function is to protract (abduct) the scapula, rotating it upward, and holding it against the rib cage. Weakness or paralysis of the serratus anterior can lead to a condition called scapular winging, where the medial border of the scapula protrudes prominently from the back.
Rhomboid Minor: This small, rectangular muscle originates from the spinous processes of the seventh cervical (C7) and first thoracic (T1) vertebrae. It inserts onto the medial border of the scapula, near the superior angle. The rhomboid minor works to retract (adduct) the scapula, elevate it, and rotate it downward.
Rhomboid Major: Located inferior to the rhomboid minor, the rhomboid major originates from the spinous processes of the second through fifth thoracic vertebrae (T2-T5). It inserts onto the medial border of the scapula, from approximately the level of the scapular spine to the inferior angle. Like the rhomboid minor, it retracts, elevates, and downwardly rotates the scapula.
Levator Scapulae: As the name suggests, the levator scapulae's primary action is to elevate the scapula. It originates from the transverse processes of the first four cervical vertebrae (C1-C4) and inserts onto the superior angle and the superior part of the medial border of the scapula. It also contributes to downward rotation of the scapula.

The coordinated action of these muscles allows for a wide range of scapular movements, which are essential for proper shoulder function. These movements include:

Elevation: Shrugging the shoulders upward.
Depression: Lowering the shoulders downward.
Retraction (Adduction): Squeezing the shoulder blades together.
Protraction (Abduction): Reaching forward, moving the shoulder blades apart.
Upward Rotation: Rotating the inferior angle of the scapula laterally and upward (e.g., raising your arm overhead).
Downward Rotation: Rotating the inferior angle of the scapula medially and downward (e.g., lowering your arm from an overhead position).

Clinical Significance: Pain, Dysfunction, and Scapular Winging

The medial border of the scapula and the muscles that attach to it are susceptible to injury and dysfunction, leading to pain and limited range of motion. Common issues include:

Muscle Strains: Overuse, trauma, or poor posture can strain the rhomboids, levator scapulae, or serratus anterior muscles. This can result in pain along the medial border of the scapula, muscle spasms, and difficulty with scapular movement.
Myofascial Pain: Trigger points in the muscles surrounding the scapula, particularly the rhomboids and trapezius, can refer pain to the medial border.
Scapulothoracic Bursitis: Inflammation of the bursa (a fluid-filled sac that reduces friction) between the scapula and the rib cage can cause pain and a grinding sensation during scapular movement.
Nerve Injuries: Damage to the long thoracic nerve (which innervates the serratus anterior) or the dorsal scapular nerve (which innervates the rhomboids and levator scapulae) can lead to muscle weakness or paralysis. As mentioned earlier, long thoracic nerve palsy results in scapular winging. Dorsal scapular nerve injury can cause difficulty with scapular retraction and elevation.
Thoracic Outlet Syndrome (TOS): Compression of nerves and blood vessels in the space between the clavicle and the first rib can cause pain, numbness, and weakness in the shoulder and arm. This can sometimes affect the muscles around the scapula and lead to pain along the medial border.
Postural Problems: Poor posture, such as rounded shoulders and a forward head, can place excessive strain on the muscles that attach to the medial border, leading to pain and dysfunction.
Scapular Dyskinesis: This refers to altered scapular movement patterns. It can be caused by muscle imbalances, nerve injuries, or structural abnormalities. Scapular dyskinesis can contribute to shoulder pain and instability.

Scapular winging, in particular, is a notable clinical sign. It occurs when the serratus anterior muscle is weak or paralyzed, causing the medial border of the scapula to protrude away from the rib cage. This can be caused by:

Long Thoracic Nerve Injury: As mentioned previously, damage to the long thoracic nerve is the most common cause of scapular winging. This nerve can be injured during surgery, trauma, or repetitive activities.
Muscle Weakness: In some cases, scapular winging can be caused by weakness of the serratus anterior muscle due to disuse or other underlying medical conditions.
Other Neurological Conditions: Certain neurological conditions, such as muscular dystrophy, can also cause scapular winging.

Symptoms of scapular winging include:

Protrusion of the medial border of the scapula, especially when pushing against a wall or performing other activities that require protraction of the scapula.
Shoulder pain and weakness.
Difficulty with overhead activities.
Limited range of motion in the shoulder.

Assessment and Diagnosis

A thorough physical examination is essential for diagnosing conditions affecting the medial border of the scapula. This typically involves:

Medical History: Gathering information about the patient's symptoms, activities, and any previous injuries.
Observation: Assessing the patient's posture and observing any visible abnormalities, such as scapular winging.
Palpation: Feeling for tenderness, muscle spasms, or trigger points along the medial border and in the surrounding muscles.
Range of Motion Testing: Assessing the patient's active and passive range of motion in the shoulder and scapula.
Muscle Strength Testing: Evaluating the strength of the muscles that attach to the medial border, such as the serratus anterior, rhomboids, and levator scapulae.
Special Tests: Performing specific tests to assess for scapular dyskinesis, nerve injuries, or other underlying conditions. For example, the wall push-up test can help identify serratus anterior weakness.

In some cases, imaging studies may be necessary to confirm the diagnosis or rule out other conditions. These may include:

X-rays: To evaluate for fractures or other bony abnormalities.
MRI: To assess for soft tissue injuries, such as muscle strains, rotator cuff tears, or nerve compression.
Nerve Conduction Studies: To evaluate nerve function and identify any nerve injuries.

Treatment Approaches

Treatment for conditions affecting the medial border of the scapula typically focuses on pain relief, restoring muscle strength and function, and correcting any underlying biomechanical issues. Common treatment approaches include:

Rest and Activity Modification: Avoiding activities that aggravate the pain.
Pain Management: Using pain relievers, such as over-the-counter or prescription medications, to manage pain.
Ice and Heat Therapy: Applying ice or heat to the affected area to reduce pain and inflammation.
Physical Therapy: A comprehensive physical therapy program is often the cornerstone of treatment. This may include:
- Manual Therapy: Techniques such as massage, joint mobilization, and soft tissue mobilization to address muscle tightness, trigger points, and joint restrictions.
- Therapeutic Exercises: Exercises to strengthen the muscles that control scapular movement, improve posture, and restore normal biomechanics. Specific exercises may target the serratus anterior, rhomboids, levator scapulae, and trapezius muscles. Scapular stabilization exercises are particularly important.
- Stretching: Stretching exercises to improve flexibility and range of motion in the shoulder and scapula.
- Postural Education: Instruction on proper posture and body mechanics to prevent recurrence of symptoms.
Injections: In some cases, injections of corticosteroids or local anesthetics may be used to relieve pain and inflammation.
Nerve Blocks: If nerve pain is a significant component, nerve blocks may be considered.
Surgery: Surgery is rarely necessary for conditions affecting the medial border of the scapula. However, it may be considered in cases of severe nerve injuries or structural abnormalities.

Rehabilitation and Prevention

Rehabilitation is crucial for restoring full function after an injury or condition affecting the medial border of the scapula. A well-structured rehabilitation program should focus on:

Pain Management: Continue to manage pain with appropriate medications, ice, or heat.
Restoring Range of Motion: Gradually increase range of motion in the shoulder and scapula with stretching exercises.
Strengthening Exercises: Progressively strengthen the muscles that control scapular movement.
Functional Exercises: Gradually return to functional activities, such as lifting, pushing, and pulling.
Sport-Specific Training: If the patient is an athlete, sport-specific training may be necessary to prepare them for return to competition.

Prevention is also important for avoiding injuries and conditions affecting the medial border of the scapula. Preventive measures include:

Maintaining Good Posture: Practice good posture throughout the day, especially when sitting at a desk or working on a computer.
Regular Exercise: Engage in regular exercise to strengthen the muscles that support the shoulder and scapula.
Proper Lifting Technique: Use proper lifting technique to avoid straining the muscles in the back and shoulder.
Avoiding Overuse: Avoid overuse of the shoulder and scapula muscles.
Stretching Regularly: Stretch the shoulder and scapula muscles regularly to maintain flexibility.
Ergonomic Assessment: Ensure that your workstation is ergonomically designed to minimize strain on the shoulder and scapula.

The Medial Border: An Essential Component of Shoulder Function

The medial border of the scapula, often referred to as the vertebral border, is more than just a bony landmark. It's a critical attachment site for muscles that orchestrate scapular movement, contributing significantly to overall shoulder function and stability. Understanding its anatomy, the muscles that interact with it, and the potential clinical issues that can arise is key for healthcare professionals in diagnosing and treating shoulder pain and dysfunction. By focusing on proper assessment, targeted treatment, and preventive strategies, we can help individuals maintain healthy scapular function and prevent debilitating shoulder problems. Ignoring the crucial role of the medial border can lead to misdiagnosis and ineffective treatment strategies, ultimately hindering the patient's recovery and long-term well-being. Therefore, a comprehensive understanding of this anatomical region is paramount for optimal patient care.