Sore, tight, or injured lats might make it uncomfortable to take deep breaths. Tight latissimus dorsi has been shown to be one cause of chronic shoulder pain and chronic back pain. Because the latissimus dorsi connects the spine to the humerus, tightness in this muscle can manifest as either sub-optimal shoulder function which leads to chronic pain or tendinitis in the tendinous fasciae connecting the latissimus dorsi to the thoracic and lumbar spine.
Foam rolling your lats is a simple process that helps and prevents. Please, read the general instructions on how to foam rolling, here.