College of Massage Therapists of British Columbia (CMTBC) Practice Exam

Which of the following bony landmarks is not palpable externally?

1. Glabella

2. Mandibular fossa

3. Inferior nuchal line

4. Inferior occipital protuberance

The correct answer is: Inferior occipital protuberance

The inferior occipital protuberance is not externally palpable because it is located internally on the occipital bone at the back of the skull. This protuberance is situated beneath the level of the skin and underlying tissues, making it difficult to access and feel from the outside. In contrast, the other bony landmarks listed are more accessible. The glabella, which is the smooth area between the eyebrows, is superficially located and can be easily felt. The mandibular fossa forms a part of the temporal bone where the mandible fits, and while it is slightly more challenging to palpate than the glabella, it can be accessed in the region beneath the ear. The inferior nuchal line, a ridge on the occipital bone where muscles and ligaments attach, is also palpable along the back of the skull. Thus, the distinguishing factor for the inferior occipital protuberance lies in its anatomical positioning, which makes it unreachable through external palpation, unlike the other landmarks that are more prominent and accessible.