Meeting Abstract

LBS1.2  Thursday, Jan. 3  Electromyography and the evolution of motor control: insights and limitations. HERREL, A*; AERTS, P; Univ. Antwerp; Univ. Antwerp anthony.herrel@ua.ac.be

Electromyography, or the study of muscle activation patterns, has long been used to infer higher level control and the evolution thereof. As the activation of the muscles at the level of the periphery is largely a reflection of descending control, electromyography can be an important tool to investigate how the coordination of complex, integrated musculoskeletal systems has changed (or not) over evolutionary time. The relative onset and timing of activation of a set of muscles can be used to evaluate changes in coordination of the components in a musculoskeletal system. Although somewhat limited by variability in the recruitment of different muscle fiber type populations within a single muscle (depending of the functional task at hand), and by left-right asymmetries in activation, this has proven to be a relatively robust assessment of higher level coordination. The magnitude of muscle recruitment, on the other hand, is solely dependent on the instantaneous demands imposed on the system and occurs likely by general recruitment principles. Thus, it is crucial to compare control for similar functional tasks to make meaningful inferences about evolutionary changes. Moreover, inferences about the evolution of motor control are limited in their explanatory power without proper insights into the kinematics and dynamics of a system. Identical activation patterns may imply radically different control strategies in systems constrained by morphology and/or mechanics. These aspects will be illustrated using examples of the evolution of the feeding system in reptiles and the locomotor system in lizards and frogs.