Final answer:
The statement that someone must always have a firm grip on the gurney when a patient is on it is true, as it is a critical safety measure to protect the patient.
Step-by-step explanation:
When a patient is on the gurney, the statement that someone must always have a firm grip on the gurney at all times is TRUE. This is a necessary safety precaution to ensure that the patient is secure and to prevent any accidents or injuries from occurring.
If the patient is not properly secured or if the gurney is not being handled correctly, there is a risk of the gurney tipping over or the patient falling off, which could result in serious harm. This principle is a matter of standard medical practice and patient care.