Some of these opinions may contain information about treatments or uses of drug products that have not been approved by the U.S. Food and Drug Administration. WebMD does not endorse any specific product, service, or treatment. Do not consider WebMD User-generated content as medical advice.
Intercostal retractions occur when the muscles between the ribs pull inward. The movement is most often a sign that the person has a breathing problem. Intercostal retractions are a medical emergency.
Intercostobrachial Nerve Syndrome and Treatment. Intercostobrachial nerve syndrome is a nerve entrapment that causes pain on the back and inside of the upper arm, which can also radiate to the chest. The intercostobrachial nerve is a sensory nerve only and does not control any muscle movement. It originates from branches in the upper thoracic.