Fig. 5

Whole-muscle physiology experiments showed the Neb^Y2303H,Y935X EDL muscle was susceptible to eccentric contraction-induced damage. a, b Whole-muscle in vitro contractile analysis of extensor digitorum longus (EDL) and soleus (SOL) from male mice at 7 months of age showed a significant deficit in normalised force production in Neb^Y2303H,Y935X at low-stimulation frequencies. c, d EDL Neb^Y2303H,Y935X muscle was more susceptible to damage by eccentric contractions involving stretches to 120 to 140% of L_o than wild type. e, f Transient stretch-induced force responses were higher in Neb^Y2303H,Y935X EDL muscles compared with wild type, suggesting increased stiffness in Neb^Y2303H,Y935X EDL muscles. In contrast, transient stretch-induced force responses were lower in Neb^Y2303H,Y935X SOL muscles compared with wild type, suggesting greater compliance in Neb^Y2303H,Y935X SOL muscles. n = 7, Two-way ANOVA, *p < 0.05; **p < 0.005; #p < 0.0005; ¤p < 0.0001