Your concerns are very common. The person giving the test is usually a trained professional such as a physical or occupational therapist. They are aware of your health history and previous injury. The test is usually designed to start slowly and build up.
Patients are often given the chance to rate the activity. For example, you may be asked on a scale from one to 10 to say if a load is light (one) or too heavy (10). Patients may be told to stop the activity if the load is an eight or more. The therapist will also stop you if there’s a concern about poor lifting posture.
Vital signs, such as heart rate and blood pressure may be measured. You won’t be allowed to go past a maximum level. This is decided based on your age. A heart monitor may be used to measure this throughout the activity. Sometimes, the therapist just measures vital signs at regular time periods.
Before starting, talk with the person giving the test. Explain your concerns and see what he or she has to say.