ROM is an abbreviation of 'range of motion'.
Plastic goniometer for measuring ROM.
Normal range of motion
Normal ROM is usually minus 5 to 143 degrees in women and minus 6 to 140 degrees in men.
Clinical measurement of range of motion. Review of goniometry emphasizing reliability and validity. Gajdosik RL and Bohannon RW. Phys Ther. 1987 Dec;67(12):1867-72.