The commission or any member thereof may, upon the application of either party or upon its own motion, appoint a disinterested and duly qualified physician or surgeon to make any necessary medical examination of any employee and to testify in respect thereto. The physician or surgeon must be allowed traveling expenses and a reasonable fee in accordance with a fee schedule set by the commission. The commission may allow additional reasonable amounts in extraordinary cases. The commission or any member thereof has the discretion to order either party to pay the fees and expenses of the physician or surgeon, or the commission or any member thereof may order the parties to share responsibility for payment of the fees and expenses.