Fig. 10. Force enhancement due to passive pre-stretch in muscle 178. (A) Force plotted as a function of time. The thin black line represents the force measured in muscle 178 when stimulated isometrically at the longer length and serves as the control. The thick blue line represents the force measured in muscle 178 when stretched just prior to an isometric contraction. Force traces are aligned with respect to the stimulation to show the change in force with and without a passive pre-stretch. In this representative trial, the passive pre-stretch (thin, black line) enhanced the force generated by 6% as compared to the force generated during the control contraction (bold, blue line). (B) Muscle length and stimulation (yellow squares) plotted as a function of time of the contraction with the passive pre-stretch (thick, blue line) compared with the control contraction (thin, black line).