Fig. 5. Tetanic force versus sarcomere length recorded in mouse single muscle fibers. (A) Force expressed in units of the tetanic force recorded near 2.4 µm sarcomere length. The straight line is linear regression of force upon sarcomere length for values between 2.35 and 4.00 µm sarcomere length. Asterisks along the ascending limb are calculated force values based on the assumptions described in text. (B) Schematic illustration of different degrees of overlap between thick (A) and thin (I) filaments. O_S, single filament overlap; O_D, double filament overlap; O_C, compression of thick filaments when colliding with Z disks at short (<1.7 µm) sarcomere lengths. Reproduced, with permission, from Edman and Reggiani (1987). For further information, see text.