The anterior and posterior canals are well developed.

Modern humans have bigger arcs on their anterior and posterior canals, which reflect greater angular motion along the sagittal plane.

It can be triggered by any action which stimulates the posterior semi-circular canal which may be:

For some patients, this maneuver may not be indicated and a modification may be needed that also targets the posterior semicircular canal.

Tumors are polypoid, identified most often in the posterior canal.

Anterior and posterior canals may be collectively called vertical semicircular canals.

Both anterior and posterior canals are orientated at approximately 45 between frontal and sagittal planes.

In most cases it is the posterior canal that is affected.

Upbeating nystagmus indicates that the vertigo is present in the posterior semicircular canal of the tested side.

The wide margins are usually dark brown and the anterior and posterior canals end into well developed 'rostra'.