GROWTH-PATTERNS OF 3 HINDLIMB MUSCLES IN CHICKEN

Abstract

The growth patterns of [chicken] biceps femoris, adductor superficialis and adductor profundus were studied relative to the functional-biomechanical demands of increasing body size. All 3 muscles exhibited positive allometry (relative to body weight) in muscle length but only biceps femoris and adductor profundus showed positive allometry in cross-sectional area. The adductor superficialis was isometric. In biceps femoris and adductor superficialis, the lengths of the longest and shortest fasciculi grew at equal rates, whereas in adductor profundus the shortest fasciculi grew faster than the longest. Biceps femoris grew relatively faster in terms of wet and dry weight than did the adductors. Muscle weight alone was an insufficient indicator of changing function in growing muscle. Growth studies should include other functionally relevant measurements such as cross-sectional area or fiber length.