Breathing difficulties

[leakd]

Does muscle tone affect one's ability to breath?  If the intercostal muscles are all in constant spasm, would this make breathing difficult?

[Cleveland Clinic]

We mostly use our diaphragm (big muscle that separates the belly from the chest) for breathing at rest and normal activity.  During exertion, we tend to incorporate our intercostal muscles.  So it is possible to be short of breath or have exertional insufficiency when those muscles aren't working well.  More importantly, you have to find out why those muscles in a constant spasm and try to take some meds or go through physical therapy in order to make that better.