Fulcrum Health Inc., which operates one of the largest independent networks of credentialed chiropractors in the Upper Midwest, announced it will open a new, larger headquarters this month in Plymouth, Minn., as part of a planned expansion of the network. The nonprofit health care organization said the space will accommodate a projected 20 percent staff increase through 2018. Fulcrum operates the ChiroCare network, which includes more than 2,400 chiropractors in Iowa, Minnesota, Nebraska, North Dakota, South Dakota and Wisconsin. Fulcrum also announced the appointment of Shireen Stone as chief operating officer. Before joining Fulcrum, Stone held leadership roles at Park Nicollet Health Services and HealthEast Care System, and most recently with CliftonLarsonAllen LLP, providing advisory services to a national base of health system, hospital and physician practice clients.