a shoulder immobilization apparatus / device which allows simultaneous immobilization of shoulders in both anterior / posterior directions as well as superior / inferior direction using shoulder straps . the straps are attached to a base board . the base board is configured to be used in conjunction with standard components including : treatment couch , head support boards , head support , thermoplastic masks , and indexing bars . the device uses only low attenuation components in the treatment area . the use of nonconductive materials makes the device suitable for use with mri machines .