Kids Up, the Montana-based manufacturer of dynamic seating systems for children, is shutting its doors on Dec. 31.

A customer service representative answering the phone on Dec. 17 said the company has already stopped shipping product. The rep referenced “a few business issues” in explaining that Kids Up was closing. On Monday, Dec. 20, callers received a recorded explanation that the company had ceased operations. Callers can leave a voice mail message if they need assistance.

In 2007, Kids Up announced a partnership with Sunrise Medical’s A.R.T. Group, which would distribute and market the Kids Rock dynamic seating systems in the United States.

But by late 2009, that agreement had ended. In documents regarding an application for an economic development loan from the city of Belgrade, Mont. – where Kids Up is located – Kids Up President Dale Mandeville cited issues of competition with Sunrise Medical, and said that the partnership between the two had ended. Mandeville said the company expected “a substantial increase in revenue” for 2010, thanks in part to the launch of a new product that would accommodate larger children.

Kids Up described its dynamic seating system as one “that accommodates and encourages children with abnormal — strong or weak — extensor tone patterns by allowing a controlled range of extension at the hips and knees. The system allows the controlled movement while maintaining proper pelvic positioning.”

The system had been the subject of research by Michael Hahn, Ph.D., Montana State University, who first presented his findings at the 2007 International Seating Symposium in Orlando, Fla. Kids Up said parents, therapists and teachers of children using the seating systems reported a range of benefits, including “increased interaction with peers, sleeping through the night, improved verbal skills (and) increased range of motion at the hips and knees.”