Signing a medical release form after a car accident isn't really a yes or no question because there are some forms that must be signed but there are certain ones that you don't have to and shouldn't sign.
Because Florida is a no fault state, your own insurance up to $10,000 is going to pay for your medical bills. They may ask you to sign a medical release form to make sure they get the proper records from the doctor. This form is one that you should sign.
However, if the other driver's insurance company contacts you and asks you to sign a medical authorization form you should be hesitant to do so. You have no responsibility to give them access to your private medical records and if you have a claim your lawyer will take care of gathering the proper forms from your doctor in order to pursue your case. It is in your best interest to not sign the medical release forms from the insurance company of the driver who caused the accident.