Inferior view, inferior nuchal lines 
Inferior view, superior nuchal lines 
Inferior view, median nuchal line The nuchal lines of the occipital bone are where many muscles and ligaments of the neck and back attach to the
skull. Generally areas that serve as points of attachment for muscles have
raised bone due to the stress on the bone and the stimulation that causes
bone growth. The median nuchal line is also known as the external
occipital crest and this is formed because of the attachment of the ligamentum
nuchae that connects the cervical vertebrae to the skull. The superior and
inferior nuchal lines form attachments with the muscles and ligaments that
stabilize the articulation of the occipital condyles with the atlas, thereby
balancing the mass of the head over the cervical vertebrae. The superior
nuchal lines are adjacent to the external occipital protuberance, while the
inferior nuchal lines are approximately 2.5 centimeters (1 inch) inferior to the
superior nuchal lines. The superior nuchal line of the
occipital bone is of special functional importance because it is the origin
for:
1. the trapezius muscle,
and the insertion for:
1. the sternocleidomastoid muscle (lateral half of the
superior nuchal line),
Lateral view of
sternocleidomastoid insertion, right side
The above drawings of the origin
and insertion might help visualize this information (red is the origin, blue the
insertion).
COPYRIGHT 2009
by William C. Johnson II
ALL RIGHTS RESERVED!
