An adjustable neck brace worn at a human neck for fixing a cervical
vertebra includes a cover panel and an adjusting device fixed onto a
surface of the cover panel, and the adjusting device includes an
adjusting rod, a limit member and an adjusting knob disposed on a surface
corresponding to the adjusting rod, and an end of the limit member
includes a bracket, and the adjusting knob links an adjusting gear
installed at the adjusting rod, and an end of the adjusting rod includes
a height adjusting plate having a supporting portion for supporting a
chin. With the foregoing technical measures, the invention features a
secured and stable structure to maximize the effects of medical treatment
and physical therapy. The height of the supporting portion can be
adjusted to provide users a feedback about a definite feel of the
adjustment through the bracket.