Soft tissue cases are hard to prove because soft tissue injuries can occur without visible symptoms. You can suffer a sprain, strain or muscle pull without it showing on the outside. That means you’re often the only witness to your physical injuries.
Even where your soft tissue injuries are extreme, the responsible driver and the insurance companies are sure to take advantage of a situation where they think they can deny your claim. They might say that you’re exaggerating your injuries to collect more compensation than you deserve. The other driver and the insurance company might think that they can get away with not paying you because it’s your word against theirs.