The risk for respiratory complications and infections is substantially increased in old age,
which may be due, in part, to sarcopenia (aging-related weakness and atrophy) of the
diaphragm muscle (DIAm), reducing its force generating capacity and impairing the ability to
perform expulsive non-ventilatory motor behaviors critical for airway clearance. The aging-
related reduction in DIAm force generating capacity is due to selective atrophy of higher
force generating type IIx and/or IIb muscle fibers, whereas lower force generating type I and …