Figure 2.
(A) Schematic showing the force–sarcomere length relation of a diaphragm fiber of a control patient; SLopt is the sarcomere length at which maximal force is generated; SL50 is the sarcomere length at which 50% of maximal force is generated; SLmax is the sarcomere length at which no force is generated. Right panel shows schematics of a sarcomere with the corresponding lengths. (B) Force–sarcomere length relation of diaphragm fibers of 12 critically ill and 12 control patients are shown; note that both relations overlap. Force is presented as percentage of maximal force. (C–E) SLopt (C), SL50 (D), and SLmax (E) are comparable between critically ill and control patients. Note that SLopt, SL50, and SLmax were not different between slow- and fast-twitch fibers (data not shown), and therefore these data are pooled. Also, in line with previous work (13–15), the maximal force-generating capacity was lower in both slow- and fast-twitch fibers of critically ill patients (data not shown). Each data point represents the average of ∼10 fibers per subject. Data presented are mean ± SEM. Con = control patients; Crit.Ill = critically ill patients; NS = not significant.