164.310(c) - Implement physical safeguards for all workstations that access electronic protected health information, to restrict access to authorized users.

The Workstation Security standard addresses how workstations are to be physically protected from unauthorized users. Covered entities may implement a variety of strategies to restrict access to workstations with EPHI. One way may be to completely restrict physical access to the workstation by keeping it in a secure room where only authorized personnel work.