has been suggested by Banzett et
al.,23 who showed that normal subjects
could achieve higher minute
ventilations with their arms supported
on a table, rather than unsupported
at their sides. Depending
on the level and completeness of
the SCI, the function of these muscles
may be preserved because they
are innervated by cervical nerve
roots and the accessory nerve (cranial
nerve XI). These muscles include
the scalene, the sternocleidomastoids,
the trapezii, and the pectoralis
major.
Studies of the scalene muscles
using needle EMG in normal subjects
have demonstrated that they are active
during quiet breathing in both
the supine and upright posture and,
thus, should be considered primary,
not accessory, muscles of inspiration.11,24
Coordinated contraction of
these muscles seems to be necessary
for the rib cage to achieve a full rang