The duration of use depends on the type and level of injury you are facing. In general, the patients need to wear it for an entire day during the first three weeks of the injury. However, in many cases, it can take more time to recover. And during the use, the doctors may also recommend decreasing the hours per day to use these collars. Therefore it is important to consult the experts before using these collars. You should follow the advice carefully to heal your body and avoid any further damage.