What is STAM?
STAM is abnormal movement of the scapula, or shoulder blade, caused by an imbalance of the muscles around the shoulder. This usually occurs when the muscles in the front of the shoulder are very tight and the muscles in the back are less active, causing the shoulder blade to tilt forward during shoulder motion. Besides affecting the muscles in the shoulder, back, and chest, STAM can also put pressure on the nerves and blood vessels that extend from the neck into the arms and hands.
What are the symptoms of STAM?
STAM symptoms vary depending on the underlying cause of the condition.
Patients with STAM may experience
- Pain
- Restricted range of motion (for example, how far the arm can be raised to the front or side)
- Numbness and tingling into the hand
- ‘Winging’—a phenomenon where the shoulder blades “stick out” from the patient’s back when the arm is raised
Left untreated, STAM generally progresses over time with worsening of symptoms.
What Causes STAM?
Among the causes of STAM are:
- Viral illness resulting in parsonage turner syndrome
- Traumatic injury
- Repetitive use injury
- Anatomical abnormality
- “Miscommunication” between the nerves and muscles guiding movement in the shoulder