Worker won’t abide by doctor’s orders: Can we terminate?

Q: I have a Rules of Conduct Policy which is progressive and categorized by the seriousness of the offense. Can the failure or refusal of an employee receiving worker's compensation benefits to follow the course of treatment prescribed by the worker's comp doctor be included as a Rules of Conduct violation allowing me to terminate that employee if the failure/refusal continues? For instance, if the employee fails to attend physical therapy as prescribed but continues to complain of pain and is unable to return to regular work? – Sallie, Pennsylvania