HES 319 Lecture Notes - Vastus Lateralis Muscle, Accessory Muscle, Agonist
Document Summary
Sarcomeres (contractile units) either in series or parallel. L total change in length n - # sarcomeres. F total force n -# sarcomeres f force each can exert. The architectural features of a muscle affect force production considerably. A pennated arrangement allows for more fibers in the same volume of muscle. The arrangement of fibers in a muscle differs depending on muscle. Biceps must change length a lot shoulder and elbow. Vastus lateralis pennated, fibers at angle, in parallel. Physiological cross sectional area is the cross sectional area taken perpendicular to the muscle fibers. Pennated muscles produce more force than a non-pennated muscle of the same volume greater cross-sectional area. Properties of muscle that are unrelated to the magnitude of the descending command from the central nervous system exert a substantial influence on the force output of muscle. Control of submaximal motor forces discrete movements. Goal-directed movements of limbs usually involve coordinated activation of both the agonist and antagonist muscles.
