Fig. 7. Force-length characteristics of fully dissected rat medial gastrocnemius (GM) muscle with only the neuro-vascular tract as extramuscular connective tissue. GM had been dissected free from extramuscular tissues except for its innervation, blood supply and associated connective tissues. (A) Active forces exerted at the proximal tendon (closed symbols) and at the distal tendon (calcaneal bone) (open symbols). (B) Passive forces exerted at the proximal tendon (closed symbols) and at the distal tendon (calcaneal bone) (open symbols). Muscle-tendon complex length (L_m+t) is expressed as deviation from optimum GM muscle-tendon complex length (L₀). Force is shown as mean ± S.E.M.