The interscapular region, the area of the upper back situated between the shoulder blades, is supported by the twelve vertebrae of the thoracic spine and a complex network of muscles. Pain in this area is a common complaint, affecting a significant portion of the population over a lifetime. This discomfort can range from a mild ache to a sharp, debilitating sensation. The reasons for this pain are varied, involving simple mechanical issues related to muscles and joints, and less frequently, referred pain from internal organs. This article explores the common causes behind pain in the upper back, but it is not a substitute for professional medical advice, diagnosis, or treatment.
Muscular Strain and Postural Stress
The majority of pain experienced between the shoulder blades originates from the strain and fatigue of the soft tissues in the area. The upper back relies on a group of muscles, including the rhomboids, trapezius, and erector spinae, to maintain posture and stabilize the shoulder blades during arm movements. When these muscles are subjected to prolonged, low-level stress, they can become overworked and develop a dull, aching pain.
Poor posture, such as the common forward head and rounded shoulder position, causes a chronic lengthening and weakening of these supporting muscles. This postural stress forces the trapezius and rhomboids to work constantly just to hold the head and shoulders in a semi-upright position, leading to muscle fatigue and eventual strain. The muscle tissue responds to this chronic overload by tightening and becoming inflamed.
This inflammation can lead to the formation of myofascial trigger points, often described as “knots,” which are hyperirritable spots within a taut band of muscle. These trigger points are a source of localized pain and can also refer pain to other nearby areas, contributing to the persistent sensation of tightness and discomfort. The pain from muscle strain is typically described as a generalized ache that worsens with specific movements or prolonged static positions.
Joint Dysfunction in the Thoracic Spine
Beyond the muscular causes, pain can also arise from the bony structures and small joints of the thoracic spine. The thoracic vertebrae are connected by facet joints, which are small, paired synovial joints that guide and limit spinal movement. Irritation or minor restrictions in these facet joints, sometimes called thoracic facet syndrome, can generate sharp, localized pain.
The ribs also articulate with the thoracic vertebrae at the costovertebral joints. Dysfunction here can lead to a sharp, stabbing pain that is often felt deep within the back. When movement in these joints becomes restricted, it may feel like the spine needs to be adjusted to find relief. This restriction can be caused by degenerative changes like early arthritis or by minor trauma that forces the joint out of its normal alignment.
While less common in the thoracic region compared to the neck or lower back, a bulging or herniated disc can still occur and cause interscapular pain. When a disc’s inner material pushes out, it can press on the nerves exiting the spinal cord, sending pain signals to the upper back. This type of discomfort is often accompanied by tingling, numbness, or pain that radiates toward the chest or down the arm.
Daily Habits That Contribute to Pain
Specific daily actions and habits are often the root cause that drives muscle strain and joint issues in the upper back. Prolonged static positioning, such as sitting at a computer desk for hours or lengthy periods of driving, is a major contributor to this pain. Remaining in one posture for an extended time leads to muscle imbalances and forces the stabilizing muscles to work without sufficient rest, resulting in fatigue and discomfort.
Improper mechanics during physical activities also place undue stress on the spine and surrounding soft tissues. For example, lifting heavy objects with poor form or engaging in repetitive movements that strain the shoulder can cause microtrauma to the muscles and ligaments. This repetitive strain can accumulate over time, leading to chronic inflammation and vulnerability to acute injury.
Carrying heavy bags, particularly shoulder bags or backpacks worn on one side, unevenly distributes weight across the upper back and shoulder girdle. This uneven load forces the muscles on the loaded side to overcompensate, accelerating muscle fatigue and the development of painful trigger points. Emotional stress and tension can also manifest physically, causing an unconscious and chronic elevation of the shoulders, which contributes significantly to muscle spasm and interscapular pain.
Recognizing Serious Underlying Conditions
In rare instances, interscapular pain is referred pain from a problem with an internal organ. Referred pain occurs because the nerves supplying internal organs share pathways with the nerves that supply the skin and muscle of the upper back, causing the brain to misinterpret the location of the pain. Conditions affecting the heart, for example, can present as pain between the shoulder blades, particularly in women, and may accompany other symptoms like chest pressure or shortness of breath.
Gastrointestinal issues are another source of referred pain to this region. Gallbladder inflammation or gallstones can cause pain that radiates from the upper right abdomen to the area between the shoulder blades. Similarly, conditions affecting the esophagus, such as severe acid reflux, may lead to a burning sensation that is felt in the back. Pulmonary issues, like a blood clot in the lung (pulmonary embolism) or a severe lung infection, can also cause referred pain to the upper back.
There are specific “red flags” that indicate the pain requires immediate medical attention, as they may signal a life-threatening condition. These urgent symptoms include:
- Pain accompanied by sudden shortness of breath, dizziness, chest tightness, or a sensation of impending doom.
- Pain that is constant and unrelenting, especially at rest or at night.
- Pain coupled with unexplained weight loss.
- Fever.