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the 5th rib, the SFL does not, and you can continue up
the sternal area, including the tissues superficial to the
sternum itself, but also the tissue overlying the sterno-
chondral joints between the sternum and the medial
edge of the pectoralis major. Generally, this tissue wants
to be moved cephalad, but sometimes, as in the case of
a pinched or narrow chest, requires a lateral vector also
(DVD ref: Superficial Front Line, 33:05-40:38).
The SFL in the neck
Following the SFL upward on these tissues between
and beneath the two medial edges of the pectoralis
major muscles, we come to the top of the front of the
sternum. A superficial glance at standard anatomy
plates seems to indicate that the logical direction from
here is to keep going straight, right up the front of the
throat to the lower part of the jaw using the infrahyoid
muscles (see Fig. 2.4A). These muscles would connect
through the hyoid to the mandible, and from the man-
dible via the jaw muscles onto the lower part of the
cranium, temptingly close to the upper end of the SBL
on the brow ridge.
But this beautiful theory is about to be destroyed by
an ugly fact: the error of following this path for the
SFL is evident as soon as we look at the lower attach-
ments of these hyoid muscles. They do not attach to
the front of the sternum, but tuck instead behind it
into the posterior aspect of the sternal manubrium, and
thus they are not on the same fascial plane as the SFL
myofasciae (see Fig. 2.4B, p. 66). In fact the hyoid group-
ing is part of the visceral cylinder of the neck, joined to
the thoracic viscera through the thoracic inlet, and
will be seen again as one route in the Deep Front Line
(see Ch. 9).
The mechanical connection from the front of the chest
to these muscles can nevertheless be felt by hyperex-
tending the neck and pointing the chin up into the air.
The discerning will notice, however, that most of that
pull extends down the inside of the rib cage, not down
the superficial surface with the SFL.
To continue up the SFL, we must look at what attaches
to the outside of the top of the sternum. What does
attach here, of course, is our familiar friend and member
of the superficial cylinder of the neck (fascia colli super-
ficialis), the sternocleidomastoid (SCM). The sternal
head, in particular, of the SCM myofascia attaches firmly
to the top and front of the sternum, interfacing with the
sternal layer that comes up under the pectoralis fascia.
This important track leads up laterally and posteriorly
to the mastoid process of the temporal bone, and onto
the lateral and posterior parts of the galea aponeurotica
(Fig. 4.22).
The fact that the myofascial pull running up the sen-
sitive front of the body makes a sudden jump via the
SCM for the back of the skull produces a very interest-
ing counter-intuitive situation. Tightening the SFL
causes flexion of the trunk, either in motion or in posture,
but produces hyperextension at the top of the neck (see
Fig. 4.23). (The SCM produces neck flexion in the supine
position, as in a sit-up, when it is lifting the head against
Fig. 4.22 The fourth and uppermost portion of the SFL is the
sternocleidomastoid (SCM) muscle, which tracks back along the
neck onto the posterior portion of the temporal bone and the
asterion - the sutural junction among the temporal, parietal, and
occipital bones, and a major attachment of the tentorium cerebelli
on its medial side.
Fig. 4.23 The SCM is uniquely positioned, in standing posture, to
create lower cervical flexion at the same time that it creates upper
cervical hyperextension. The exact cervical level where this switch
is made varies with posture, but is usually between C2 and C3.
the force of gravity Even in standing, put your hand
against your forehead and push forward with your
head, and you will feel the SCM contract. In stand-
ing posture, however, because it attaches to the mastoid
process, it runs posterior to the hinge of the atlanto-
108
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