Neuromuscular Aspect of Movements Contents of the Lesson

 Functional Aspect  Types of Muscular Tension.  Properties of 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 Functional

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 . abdominus It spread force through larger area. External oblique 2. Fusiform 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 . 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 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 Role 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  pulling towards center.

Types of Muscular tension

Isotonic Isometric

Isokinetic Muscular 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”.  “ 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

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