Inferior oblique is the smallest of the three parts of longus colli.

Proximal Attachment
It passes supero-laterally from the anterior aspect of the bodies of T1 to T3.

Distal Attachment
It attaches to the anterior tubercles of the transverse processes of C5 and C6.  

Nerve Supply
It is supplied by anterior rami of C5, C6.

Action
The inferior oblique part of longus colli flexes the neck when acting together; it brings about lateral flexion and rotation of the neck to the opposite side when acting individually.