Fig. 4.

Skinned force-pCa relationship in fast and slow-type muscle fibers. A: Ca²⁺-sensitive force development of high capacity runner (HCR) Slow soleus (SOL) fibers (black triangle) was increased compared with both HCR Fast SOL (black diamond) and extensor digitorum longus (EDL; gray square) fibers. B: contrary to its slow troponin isoform content, the Ca²⁺-sensitive force development of low capacity runner (LCR) Slow SOL (white triangle) fibers was not different from LCR Fast SOL (white diamond) or EDL (white square) fibers. C: Ca²⁺-sensitive force development of HCR Slow SOL fibers was increased compared with that of LCR Slow SOL that was not different from EDL fibers.