Final answer:
In differential diagnosing from resisted testing, 'strong and painful' refers to the strength and intensity of the resistance encountered during the test and the resulting pain or discomfort for the patient.
Step-by-step explanation:
When it comes to differential diagnosing from resisted testing, the term 'strong and painful' refers to the strength and intensity of the resistance encountered during the test. It means that the resistance is significant and causes pain or discomfort for the patient. For example, if a patient is asked to push against a resistance and they experience a strong and painful sensation while doing so, it could indicate a particular condition or injury that needs further evaluation.