back pain when breathing

Sharp lower back pain when I breathe in deeply?
I did some skull crusher exercises (where you lie on your back and lift dumbbells using your triceps), then after I got out of the shower I started getting sharp back pains in both side of my lower back when I breathe in deeply.
The pain is around the area where the rib cage ends, but in the back. The pains are like quick shocks and happen when my lungs are pretty much filled with air.
Anyone has an explanation for this?
I would go to your local emergency room. If you’re having pains when breathing, this is not a good sign, and needs to have some immediate attention to make sure that you didn’t either break a rib, or puncture a lung or the pleural membrane around the lung.
Back Pain, avoidance and rehab