The 11 intercostal muscles on each side of the rib cage connect one rib to another, working to spread the ribs apart and bring them back together again as the chest expands and contracts during breathing. The intercostals are also part of the core muscle group that is integral to many fundamental baseball movements. They are most often injured during a sudden contraction when they are in a stretched position, such as during a throw or swing. Because the lungs are located inside the rib cage, pain from a strained intercostal can be so severe that it feels like a broken rib.
Like all muscle strains, the intercostal strain is broken down into three grades. Grade 1 is a mild strain, Grade 2 is a moderate strain and Grade 3 is a severe strain in which the muscle ruptures.
Typical recovery time
Recovery time is dependent on the severity of the strain, with Grade 1 strains typically requiring 2-3 weeks and Grade 2 strains taking twice as long. Grade 3 strains often require surgery, however, with a 3-4 month recovery window.
In 2014, Dexter Fowler missed eight weeks with an intercostal strain. Carlos Gomez missed three weeks in 2017. David Wright missed one month of Spring Training in 2012 and then missed time in the spring of 2013 at the World Baseball Classic with the same injury.