Fig. 1. Laser flash-induced mechanical response. Typical fibre length as a % of L₀ (A) and force (B) changes of the preparation, contracting isometrically (a) or shortening isotonically (b–f) under five different afterloads. Length recordings a, b, c, d, e and f correspond to force recordings a', b', c', d', e' and f', respectively. The loads were P_o (isometric contraction, a, a'), 0.78 P_o (b, b'), 0.53 P_o (c, c'), 0.35 P_o (d, d'), 0.09 P_o (e, e') and 0 (unloaded shortening, f, f'), respectively. The initial (relaxed) length L₀ and the cross-sectional area of the fibre were 2.8 mm and 6.8x10^–5 cm², respectively.