Beneath the pectoralis major muscle in the chest is the narrow, triangular pectoralis minor muscle. It is originating from the midribs and inserts into the scapula. Pectoralis Minor Syndrome occurs when the pectoralis minor compresses the neurovascular bundle This compression can lead to various symptoms, depending on the severity and specific structures affected. In this guide, we will get you through the symptoms, diagnosis and treatment of pectoralis minor syndrome. 

What is Pectoralis Minor Syndrome?

Pectoralis Minor Syndrome (PMS) is characterised by compression of the neurovascular bundle beneath the pectoralis minor muscle, leading to a range of symptoms. This condition is often underdiagnosed and can significantly impact a person's quality of life. In this comprehensive guide, we will delve into the causes, symptoms, diagnosis, and treatment options for Pectoralis Minor Syndrome, providing a detailed overview to help you understand and manage this condition effectively.

Causes of Pectoralis Minor Syndrome

Several factors can contribute to the development of Pectoralis Minor Syndrome:

1. Poor Posture

Prolonged poor posture can cause the shortening and tightening of the pectoralis minor muscle. This can increase the risks of compression of the neurovascular bundle.

2. Repetitive Movements

Engaging in repetitive activities that involve forward shoulder movements, such as typing, driving, or certain sports, can cause muscle imbalance and strain on the pectoralis minor muscle.

3. Trauma or Injury

Direct trauma to the chest or shoulder region can cause inflammation and swelling. It can lead to compression of the neurovascular bundle beneath the pectoralis minor muscle.

4. Muscular Imbalance

An imbalance between the pectoralis minor and surrounding muscles, such as the pectoralis major and trapezius, can result in a change of biomechanics and increased pressure on the neurovascular structures.

Symptoms of Pectoralis Minor Syndrome

The symptoms of Pectoralis Minor Syndrome can be different in patients. Common symptoms include:

1. Pain and Discomfort

Individuals with Pectoral Minor Syndrome often experience pain in the chest, shoulder, and upper arm. The pain may be sharp, burning, or aching and can be exacerbated by certain movements or positions.

2. Numbness 

Compression of the brachial plexus can lead to numbness and tingling sensations in the arm, hand, and fingers. These symptoms may worsen with prolonged activity or poor posture.

3. Weakness

Muscle weakness, particularly in the shoulder and arm, is a common symptom of PMS. This can affect the ability to perform everyday tasks and activities.

4. Swelling and Discoloration

In some cases, compression of the subclavian vein can lead to swelling and discolouration of the affected arm and hand. This is one of the most severe symptoms and it may require immediate medical attention.

Diagnosis of Pectoralis Minor Syndrome

The diagnosis of Pectoralis Minor Syndrome is different among different patients. A detailed check-up by a healthcare professional is essential for proper diagnosis.

1. Medical History and Physical Examination

A deep medical history and physical examination are the very first steps in diagnosing PMS. The healthcare provider will inquire about the patient's symptoms, medical history, and any activities or positions that exacerbate the symptoms. During the physical examination, specific tests may be performed to assess the function and flexibility of the pectoralis minor muscle and the presence of neurovascular compression.

2. Imaging Studies

Imaging studies such as X-rays, MRI, or ultrasound may be ordered to visualize the structures of the chest and shoulder and rule out other potential causes of symptoms. These studies can help identify any anatomical abnormalities or signs of compression.

3. Electrophysiological Studies

Electrophysiological investigations can evaluate how well the muscles and nerves work. These studies include electromyography (EMG) and nerve conduction studies. These tests can help determine the extent of nerve compression and identify any associated nerve damage.

Treatment of Pectoralis Minor Syndrome

The treatment of Pectoralis Minor Syndrome typically involves a combination of conservative and, in some cases, surgical interventions.

Conservative Treatments

1. Physical Therapy

Physical therapy is a cornerstone of conservative treatment for PMS. A physical therapist will design a personalized exercise program to stretch and strengthen the pectoralis minor and surrounding muscles. This can help alleviate compression and improve posture and biomechanics.

2. Posture Correction

Improving posture through ergonomic adjustments and posture exercises is essential for reducing strain on the pectoralis minor muscle. This may involve modifying workstations, using supportive chairs, and practising proper body mechanics.

3. Manual Therapy

Manual therapy techniques, such as massage, myofascial release, and trigger point therapy, can help reduce muscle tension and improve flexibility in the pectoralis minor and surrounding muscles.

4. Medications

It is possible to administer muscle relaxants or nonsteroidal anti-inflammatory medications (NSAIDs) to treat pain and inflammation. In some cases, corticosteroid injections may be considered for more severe symptoms.

Surgical Treatments

1. Pectoralis Minor Tenotomy

In cases where conservative treatments fail to provide relief, a pectoralis minor tenotomy may be considered. This surgical procedure involves cutting the tendon of the pectoralis minor muscle to release the compression on the neurovascular bundle.

2. Thoracic Outlet Decompression

If PMS is associated with thoracic outlet syndrome, surgical decompression of the thoracic outlet may be necessary. This procedure aims to relieve pressure on the neurovascular structures by removing any contributing anatomical abnormalities.

Prevention of Pectoralis Minor Syndrome

Preventing Pectoralis Minor Syndrome involves adopting healthy habits and lifestyle changes to reduce the risk of developing this condition.

1. Maintain Good Posture

Practicing good posture is crucial in preventing PMS. Ensure that your workstation is ergonomically set up, and take frequent breaks to stretch and change positions.

2. Strengthening and Stretching Exercises

Incorporate regular exercises to strengthen the shoulder and chest muscles and maintain flexibility. Focus on exercises that promote balance between the pectoralis minor and surrounding muscles.

3. Avoid Repetitive Strain

Minimize repetitive movements that can strain the pectoralis minor muscle. If your job or activities involve repetitive shoulder movements, make adjustments to reduce the strain.

4. Stay Active

Engage in regular physical activity to maintain overall muscle health and prevent muscle imbalances. Activities such as swimming, yoga, and strength training can be beneficial.

Conclusion

In conclusion, the pectoralis minor muscle is located between the scapula and the shoulder. Bad posture, repetitive activities and trauma lead to suppression of this muscle which leads to pain and causes pectoralis minor. The treatment of pectoralis minor syndrome includes medical and therapeutic procedures. Good posture and exercises prevent the increase of pectoralis minor syndrome.