You have expressed an opinion that many patients, health care providers, and insurance companies have shared for quite some time. In fact, there's a trend now in health care toward what's called evidence-based medicine (EBM).
EBM directs that if there's no proof (or not enough proof) that a test, procedure, or treatment is beneficial, then it shouldn't be used without just cause. Many researchers are studying injuries, illnesses, and other health conditions with this in mind.
When it comes to diagnosing neck pain, there are many diagnostic tests available. There are surveys patients can take to measure function and disability. There are range of motion, strength, and nerve tests that physical therapists perform. Electromyography (EMG) and nerve conduction velocity can be done to further examine muscle or nerve function.
The physician may order imaging studies such as X-rays, MRIs, and CT scans. In select cases myelography (dye injected into the spinal column) and discography (dye injected into the disc) are ordered. For some patients, blood tests may be needed.
It's likely that some tests work better for certain groups or subgroups of patients. Researchers are working to find a decision algorithm (formula) that will help doctors (and others) know when to do which tests and on what patients. This will help us avoid the overuse of expensive tests that have no validity.
At the same time, it should be said that psychologic, social, and economic factors may have more to do with chronic pain then the mechanism or type of injury. These variables must be tested for as well. Again, finding factors that predict who will get better and who won't is needed. Likewise, finding patient factors that point to one type of testing over another would be helpful and cost-effective.