For extraction of protein, frozen left intercostal muscle (~30 mg) was triturated in a radioimmuno-precipitation assay buffer and protease inhibitor cocktail (1:1000, SigmaFast, Sigma-Aldrich; St.
Parasternal intercostal muscle fiber typing and morphology were then analyzed with two-way analyses of variance (ANOVAs) (MHC x group) and then Holm-Sidak-corrected pairwise contrasts when needed.
Intrinsic Transient Tracheal Occlusion and Parasternal Intercostal Muscle Fiber Cross-Sectional Area
The CSA of the parasternal intercostal muscles (Figure 1(a)) differed according to both the training group and the fiber type.
Fiber-Type Proportions of Third Parasternal Intercostal Muscles
Morphological Assessment of Third Parasternal Intercostal Muscles
Contraction of the external intercostal muscles pulls the ribs outward, thereby preventing the inward movement of the upper rib cage; the net effect is to augment the volume of inspired air (Figure 3).
We stimulated only two intercostal muscles from each hemithorax, while DiMarco et al.
This limitation was generally identified during autopsy to be caused by dislodgement of the intramuscular electrodes from their implantation site in the intercostal muscles as they had migrated to the latissimus and serratus muscles (Figure 2).
In addition, intercostal muscles include both the external and internal muscles.
Thus, stimulating along the lower thoracic ribs closer to the origin of intercostal nerves may increase abdominal muscle responses.
Including intercostal spaces two through five would be expected to have a positive effect.