Healthcare and Medicine Reference
back of the sternum, thus connecting them to a deeper
ventral fascial plane within the rib cage (part of the Deep
Front Line), not the superficial plane (Fig. 2.4B).
C. Direct vs mechanical connections
A direct connection is purely fascial, while a mechanical
connection passes through intervening bone. The exter-
nal and internal obliques thus have a clear direct con-
nection across the abdominal aponeurosis and the linea
alba. The iliotibial tract likewise ties directly into the
Fig. 2.2 While the fascia connecting the muscles that attach to
the coracoid process is always present (A), the connection only
functions in our game of mechanical tensile linkage when the arm
is above the horizontal (B). (A is reproduced with kind permission
from Grundy 1982.)
Fig. 2.3 Tendons acting around corners like pulleys are an
acceptable exception to the 'no sharp turns' rule. (© Ralph T
Hutchings. Reproduced from Abrahams et al 1998.)
Fig. 2.4 Although a mechanical connection can be felt from chest to throat when the entire upper spine is hyperextended, there is no
direct connection between the superficial chest fascia and the infrahyoid muscles because of the difference in depth of their respective
fascial planes. The infrahyoids pass deep to the sternum, connecting them to the inner lining of the ribs and the intrathoracic fascia (A).
The more superficial fascial planes connect the sternocleidomastoid to the fascia coming up the superficial side of the sternum and
sternochondral junctions (B).