In today's health care culture, evidence-based medicine (EBM) is a key byword. EBM refers to the idea that as much as possible, only treatments known to have a positive effect are used. Some treatments make a patient feel better but it's only temporary. There aren't any real lasting changes in motion or function.
In order to measure change in a patient's status, certain tests must be performed each time. There are many such tests that can be used depending on the problem the patient is being treated for. This helps the doctor or therapist judge the status of the patient.
It also helps determine whether a meaningful change has taken place. For example, say you rate your pain as a six on a scale from zero to 10. After your first treatment, it goes down to a five. But you still can't dress yourself or comb your hair without help. Your pain is improved but a meaningful change in your status hasn't occurred yet.
If every patient who is treated this way gets slight pain relief but no functional improvement, then the treatment method should be abandoned for something more effective. Testing the patient before and after is the best way to see what makes a difference.