Neuromuscular Aspect of Movements Contents of the Lesson Muscular System Functional Aspect Types of Muscular Tension. Properties of Skeletal muscle Muscular system Organ system consists of Smooth, Cardiac and Skeletal Muscles. Functional Aspect of Muscle Role/ function in the body Shape and fiber arrangement Role in the movement execution Position of origin and insertion with respect to joints Functional aspect Other classification Role/Function in the body Skeletal Muscles Smooth Muscles Cardiac Muscles ROLE: Moves ROLE: Provides motor Attached to skeletal substance inside the power to the activity of system. organs and heart. regulating internal Pumps blood ROLE: locomotion environment . and movement. Found only in heart. Shape and fiber arrangement Based on the kind of fiber of arrangement there are two category; Fiber arrangement Parallel muscle Pennate muscle Fiber arrangement- Parallel muscles Fibers are arranged parallel to the length of muscle. Produces greater range movement or higher amplitude movement. Types of parallel muscles Flat muscle Fusiform Muscle. Types of parallel muscles Strap muscle Radiate Muscle. Types of parallel muscle Circular muscle Fiber arrangement- Parallel muscles S. Name of the Feature Examples N muscle o 1. Flat muscle Thin and broad shaped Rectus Orginates from aponeurosis. abdominus It spread force through larger area. External oblique 2. Fusiform muscle Spindle shaped with a central belly. Brachialis It focuses power into bony projections. Brachioradialis 3. Strap Muscle Fibers are arranged in a long parallel and Sartorius. uniform manner. Focuses power on small bony targets. 4. Radiate Muscle Have combined arrangement of flat and Pectoralis fusiform muscles major Triangle, fan shaped or convergent. Trapezius. Originate from aponeurosis and converge into tendon. 5. Sphincter or Appears like a endless strap of muscle. Orbicularis oris. circular muscle Function to close upon contraction Fiber arrangement- Pennate muscles Have shorter fibers that are arranged obliquely to their tendon. Have greater cross-sectional area thus, have greater force production capability. Fiber arrangement- Pennate muscles S. Name of the Feature Examples N muscle o 1. Unipennate Fibers run obliquely on one side only. Biceps femoris muscle Tibialis posterior 2. Bipennate Fibers run obliquely on both side from a Rectus femoris muscle central tendon 3. Multipennate Consists of several tendon with fibers Deltoid. muscle running diagonally between them. Note: bipennate and unipennate produce strongest contraction. Role in movement execution Classifies muscle on the basis of role played in a movement. Agonist: prime movers Antagonist: contralateral muscle Stabilizers Synergist Role in movement Neutralizers Role in movement execution Ex. In biceps curl exerise Prime mover; Biceps Brachii Anta agonist: Triceps brachii Synergists: Brachialis, Brachioradialis Stabilizers: Anterior Deltoid, Upper and middle Trapezius, Levator Scapulae, Wrist Flexors Position of insertion and origin with respect to joint Based on no. of joints transversed: One joint muscle , also known as uniarticlute Two joint muscle, also known as biarticulate Multi-joint muscle ( e.g. finger flexors). Other classification Classifies as spurt and shunt. Spurt muscles Rotator or movement producing muscles Their origin is away from the concerned joint and insertion near to the joint. Thus, when they contract they apply force across the bone to produce motion . Other classification Shunt muscles Stabilizing muscle. Their insertion is away from the concerned joint and origin is near to the joint. Thus, when they contract they apply force along the bone which pulls the joint surface together and stabilize the joint. Muscular tension Muscular Contraction; “ Muscular tension” Imperative Characteristics of Muscular Contraction: Actomyosin Complex Myosin pulling actin towards center. Types of Muscular tension Isotonic Isometric Isokinetic Muscular tension Isotonic Contractions Concentric Contraction Eccentric Contraction “towards the center” “away from the center” Force of contraction> External resistance > external resistance. force of contraction. Creates movement. Modifies movement(slows it) Identify concentric and eccentric contractions in biceps muscle. Isometric Contractions. “Contracts but length stays same” Force of contraction = External force. Purpose: “fix” or “stabilize” the body part Isokinetic Contractions Like “Isotonic contraction”. “Muscle contraction with constant rate of limb movement”. But here, Done on “Accomodating Variable resistence exercise machines” or “isokinetic dynamometer” External resistence: A fixed Speed of movement ex. 15 degree/sec., etc. Properties of Skeletal Muscles Irritability : is the ability of the muscle to respond to stimulus. Contractility: is the capacity of the muscle to produce tension between it’s ends. Relaxation: is the opposite of contraction and is the giving up of tension. Both contraction and relaxation progress from zero to maximal values over a finite time. Distensibility: is the ability of the muscle to be stretched or lengthened up to a certain limit by an outside force. The muscle suffers no harm so long as it is not stretched beyond its physiological limits. Elasticity: is the ability of the muscle to recoil to its original length when an outside force is removed unless it has been overstretched. References OSTERNIG ,LOUIS.R.(1986). Isokinetic dynamometry: implications for muscle testing and rehabilitation. Exercise and Sport Sciences Reviews,14(1),pp.45-80. Shaw,Dhananjoy. (2014).Biomechanics and kinesiology of human motion.Khelsahityapublication. Newdelhi https://www.teachpe.com/anatomy/skeleton_axial.php https://www.verywellhealth.com/wolffs-law-in-physical- therapy-2696151 https://en.wikipedia.org/wiki/Muscular_system https://exrx.net/WeightExercises/Biceps/DBCurl http://nisharbasha.blogspot.com/2013/05/what-is- difference-between-spurt-and.html Floyed ,R.T.(2009). manual of structural kinesiology.,USA,ed.16. humankinetics Doubts? .