A back strain or sprain is when the muscle tendon or ligament goes beyond its stretch capacity where the muscle fibers get sometimes a little bit shredded or there are micro tears. Now I like to compare that to a rubber band. If we stretch a rubber band to its normal limit, it’s going to bounce right back. If we stretch the rubber band beyond its limit, then it may not take its normal shape or form and it may be too loose and vulnerable. And so that’s exactly what’s happening to the muscles, tendons, and ligaments.