Understanding Rib Cage Strains

The Chicago Cubs announced Friday that rookie slugger Kyle Schwarber is out for 3-5 days with a “mild rib cage strain.”
What is there to strain in there anyway?
Two options: an oblique abdominal strain, or an intercostal muscle.
Let’s talk about intercostals. (Remember Todd Hundley, catcher in the early ’00’s Cubs run? He tore one.) These are a set of small muscles run in between each rib — like the meat on a baby back rib. They assist with breathing by elevating and depressing the ribs, which in turn expands and compresses the rib cage. They are also active during trunk rotation.
Schwarber is a lefty, so when he cocks his bat in his stance he rotates his trunk all the way to the left, which stretches one set of intercostals and contracts the other. When he swings, the muscles have to powerfully switch.
To get a little technical, the internal and external intercostals work in opposite directions due to the way their muscle fibers are oriented, so one is going from a stretched position to a sudden contraction, and the other is stretching suddenly from a shortened position. It’s very hard to tell which one of these is the victim, however.
In this case, he checked his swing, causing yet another forceful change in direction in order to stop the bat’s movement, contracting suddenly from a stretched position and vice versa.
A strain happens when muscles are overstretched and damage to fibers occur. The word is that Schwarber has a “mild strain,” which equates to a Grade I strain: the overstretch of muscle or tendon, possible minor tear to some small fibers. Grade I strains usually recover on their own after a few days, but it’s important to take it slow, because early return can lead to a higher risk of re-injury, and second injury is often more severe than the first. Strains have a tendency to turn chronic, which can be a career-killer in the bigs.
What can help you prevent this from happening to you? Keeping the body in balance.
First, make sure the joints and muscles in the trunk are mobile and flexible by working on thoracic spine mobility, particularly in end range twists. Decreased shoulder mobility can affect your trunk rotation as well.
Secondly, make sure that your low back and obliques are up to snuff, and that you’re strengthening them in the rotational plane — a straight six pack won’t help you here.
Finally, don’t forget that the power and torque created from the loading and weight shift portions of your swing comes from the lower half of your body. Keep those glutes and external hip rotators as powerful as possible.