Each member of said Board shall, before entering upon the duties of the office, take the oath of office prescribed by the Constitution before someone qualified to administer oaths, and shall, except for the lay person, make oath that the member is a legally qualified practitioner of osteopathic medicine in this state; and that the member has been engaged in the active practice of osteopathic medicine in this state at least five (5) years preceding the appointment of such member.
Okla. Stat. tit. 59, § 625