Summary
Young people may develop chest and arm pain that is easily mistaken for heart disease. This is often caused by a tight pectoralis minor muscle compressing the nerves underneath it. Ultrasound-guided injection treatment together with rehabilitation can often improve symptoms effectively.
When Chest Pain Is Not a Heart Problem
From time to time, I see young patients who develop chest pain during exercise or physical work, and the pain often spreads down into the arm or fingers. Many of them first seek help from a cardiologist, but detailed cardiac investigations show no abnormal findings. In some of these cases, the real cause may be pectoralis minor syndrome.
What Is Pectoralis Minor Syndrome?
The pectoralis minor is a muscle located at the front of the chest, lying beneath the larger pectoralis major muscle. Below the collarbone, the brachial plexus — the network of nerves supplying sensation and movement to the upper limb — passes underneath the pectoralis minor. When this muscle becomes excessively tight and shortened, the space beneath it becomes smaller and can directly compress the nerves passing through it.
Causes and Common Symptoms
This condition tends to affect younger people, especially women. It is commonly related to poor control of shoulder blade movement together with repeated overhead activities such as swimming, volleyball, or weight training. Over time, these factors can cause the pectoralis minor to become shortened and stiff.
In terms of symptoms, patients may feel pain in the chest caused by muscle tightness, while pain in the arm and fingers is often related to nerve compression. In addition to pain, nerve irritation may also cause numbness in the hand, tingling in the ring and little fingers, hand weakness, and even a tendency to drop objects.
Accurate Diagnosis
Pectoralis minor syndrome can be difficult to diagnose because it may be confused with cervical nerve compression or other shoulder disorders. The doctor will first carry out a careful assessment to rule out serious and potentially life-threatening conditions such as heart disease or tumours. Once serious causes have been excluded, dynamic ultrasound may be used to assess whether the nerves show signs of compression when the arm is raised. To confirm the diagnosis further, the doctor may perform an ultrasound-guided injection of local anaesthetic into the pectoralis minor or the area where the nerve is being compressed. If the patient’s pain and numbness improve significantly after the injection, this strongly supports the diagnosis of pectoralis minor syndrome.
A Comprehensive Treatment
ApproachTreatment mainly has two aims: to relax the tight muscle and to prevent recurrence. The first part is interventional treatment. A pain specialist may use ultrasound guidance to inject botulinum toxin or anti-inflammatory pain-relieving medication into the tight pectoralis minor muscle. This can effectively and durably relax the muscle, reduce pressure on the nerves, and relieve pain. The second part is rehabilitation. Once the pain has improved, a physiotherapist can guide the patient through targeted shoulder blade control exercises and pectoralis minor stretching. This not only helps correct poor posture and movement patterns, but also reduces the risk of the condition returning.
Information provided by Dr Lee Yuk Ming, Sunny, Specialist in Pain Medicine
