A muscle cramp during pregnancy may occur in any muscle or muscle group, but is most commonly experienced in the legs. Muscle spasms that occur in the back or abdomen are also possible. A muscle cramp or spasm is characterized by the following: 1  Involuntary contraction or tightening of a muscle. 2  Usually sudden.
During breathing, these muscles normally tighten and pull the rib cage up. Your chest expands and the lungs fill with air. Intercostal retractions are due to reduced air pressure inside your chest. This can happen if the upper airway (trachea) or small airways of the lungs (bronchioles) become partially blocked.
These ribs are sometimes called the âfloatingâ ribs. The intercostal areas between the ribs contain muscles and nerves. These intercostal nerves can become damaged or inflamed due to a variety of diseases, disorders and conditions, resulting in intercostal neuralgia.Intercostal neuralgia may produce sporadic episodes of acute pain or pain that is dull and constant.n addition, pain in the rib cage area may be caused by a condition other than intercostal neuralgia that should be immediately evaluated in an emergency setting. A heart attack is an example.