Which of the following best describes postural tremor?

Postural tremor is best characterized by its emergence when a person is maintaining a specific posture against gravity, often while holding a limb in a fixed position. This type of tremor is typically seen in conditions such as essential tremor or in the presence of certain neurological disorders. The tremor is generally more pronounced when the individual attempts to hold their limbs still, which is why it is associated with specific postures.

In contrast, while postural tremor may affect various limbs, it is not limited to only the upper limbs and can be seen in other parts of the body as well. Additionally, it does not disappear with movement; in fact, it may be less noticeable during certain movements, which distinguishes it from other types of tremors like rest tremors that occur when a limb is at rest and might disappear with voluntary movement. The aspect of being unsupported plays a role in different kinds of tremors but is not a defining feature of postural tremor specifically.