TY - JOUR T1 - Functional and architectural complexity within and between muscles: regional variation and intermuscular force transmission JF - Philos Trans R Soc Lond B Biol SciPhilos Trans R Soc Lond B Biol SciPhilos Trans R Soc Lond B Biol Sci Y1 - 2011 A1 - Higham, T. E. A1 - Biewener, A. A. KW - Animals KW - Biomechanical Phenomena KW - Extremities/*physiology KW - Galliformes/*physiology KW - Locomotion/*physiology KW - Models, Biological KW - Muscle Contraction/*physiology KW - Muscle Fatigue/*physiology KW - Muscle, Skeletal/*physiology AB - Over the past 30 years, studies of single muscles have revealed complex patterns of regional variation in muscle architecture, activation, strain and force. In addition, muscles are often functionally integrated with other muscles in parallel or in series. Understanding the extent of this complexity and the interactions between muscles will profoundly influence how we think of muscles in relation to organismal function, and will allow us to address questions regarding the functional benefits (or lack thereof) and dynamics of this complexity under in vivo conditions. This paper has two main objectives. First, we present a cohesive and integrative review of regional variation in function within muscles, and discuss the functional ramifications that can stem from this variation. This involves splitting regional variation into passive and active components. Second, we assess the functional integration of muscles between different limb segments by presenting new data involving in vivo measurements of activation and strain from the medial gastrocnemius, iliotibialis cranialis and iliotibialis lateralis pars preacetabularis of the helmeted guinea fowl (Numida meleagris) during level running on a motorized treadmill. Future research directions for both of these objectives are presented. VL - 366 SN - 1471-2970 (Electronic)0962-8436 (Linking) N1 - Higham, Timothy EBiewener, Andrew AengReviewEngland2011/04/20 06:00Philos Trans R Soc Lond B Biol Sci. 2011 May 27;366(1570):1477-87. doi: 10.1098/rstb.2010.0359. U2 - 3130453 JO - Philosophical transactions of the Royal Society of London. Series B, Biological sciencesPhilosophical transactions of the Royal Society of London. Series B, Biological sciences ER -