The sternum, or breastbone, is the flat bone where the ribs meet. Sometimes, the joints can pop or crack as a person stretches or moves. A muscle spasm, an injury, costochondritis, and surgery are ...

Southwest Research Institute (SwRI) collaborated with the U.S. Air Force to ensure fleet safety after a large crack was unexpectedly found near the cockpit of a T-38 Talon. A new study describes how ...