Kinesiology of PE
Chapter 2: Neuromuscular Fundamentals
Chapter 2: Neuromuscular Fundamentals
Lumbar Nerve Root 4
Dermatome afferent (sensory): medial aspect of lower leg and foot, inner border of foot, great toe
Myotome efferent (motor) tibialis anterior, extensor hallucis and digitorum longus, peroneals
Reflexes: patella or knee extensors
function app: ankle dorsiflexion, transverse tarsal/subtalar inversion. Sensation to medial buttock lateral thigh, medial leg, dorsum of foot, great toe.
Lumbar Nerve Root 5
Dermatome afferent (sensory): lateral border of leg, anterior surface of lower leg, top of foot to middle three toes
Myotome efferent (motor): extensor hallucis and digitorum longus,peroneals, gluteus maximus and medius, dorsiflexors
REflexes None
Functional app: Great toe extension, transverse tarsal/ subtalar eversion. Sensation to upper lateral leg, anterior surface of the lower leg, middle three toes
S1
Dermatome afferent (sensry): posterior aspect of the lower 1/4 of the leg, posterior aspect of the foot including the heel, lateral border of the foot and sole
Myotome efferent(motor): gastrocnemius, soleus, gluteus maximus and medius, hamstrings, peroneals
Reflexes: Achilles reflec
Functional App: Ankle plantar flexion, knee flexion, transverse tarsal/subtalar eversion. Sensation to lateral lef, lateral foot, lateral two toes, plantar aspect of foot
S2
Dermatome afferent (sensory): posterior central strip of the leg from below the gluteal fold to 3/4 of the way down the leg
Myotome efferent (motor): gastrocnemius, soleus, gluteus maximus, hamstrings
Reflexes: None
Functional app: Ankle plantar flexion and toe flexion. Sensation to posterior thigh and upper posterior leg
S3
Dermatome afferent (sensory): groin, medial thigh to knee
Myotome efferent (motor): intrinsic foot muscles
Reflexes: None
Functional app: Sensation to groin and adductor region
S4
Dermatome afferent(sensory): Perineum, genitals, lower sacrum
Myotome efferent (motor): bladder, rectum
Reflexes: None
Functional App: Urinary and bowel control. Sensation to saddle area, genitals, anus
Proprioceptors
Internal receptors located in skin, joints, muscles, & tendons that provide feedback relative to tension, length, & contraction state of muscle, the position of the body & limbs, & joint movement.
Muscle spindles & Golgi tendon organs specific to muscles
Meissner’s corpuscles, Ruffini’s corpuscles, Pacinian corpuscles, & Krause’s end-bulbs specific to joints & skin
Kinesthesis
conscious awareness of the position & movement of the body in space.
Proprioception
unconscious awareness of the body’s position in space.
Stretch Reflex
1. Impulse sent to the CNS
2. CNS activates motor neurons of muscle to contract
All muscles possess this stretch reflex
Examples:
Hammer reflex to the quadriceps
Quick jerk of cervical spine when falling asleep
Golgi Tendon Organs (GTO)
Located close to muscle-tendon junction
Are much less sensitive to stretch than muscle spindles requiring a greater stretch reflex to be activated
GTO protects us from excessive contraction by causing the muscle to relax & antagonist to contract
Example- when a weightlifter attempts a heavy resistance during a biceps curl & reaches the point of extreme overload, the GTO is activated, the biceps relaxes & the triceps contract
Pacinian corpuscles
Around joint capsules, ligaments, tendon sheaths, & under skin
Activated by rapid changes in joint angle & by pressure changes affecting joint capsule
Are helpful in providing feedback regarding location of a body part in space during quick movements such as running & jumping
Ruffini’s corpuscles
Located in deep layers of skin & joint capsule
Activated by strong & sudden joint motion & pressure changes
Their reaction to pressure changes is slower than of Pacinian corpuscles
Are essential in providing info as to exact joint angle
Meissner's corpuscles & Krause's end-bulbs
Located in skin & subcutaneous tissues
Important in receiving stimuli from touch
All or none principle
The individual muscle fibers within a motor unit will fire & contract maximally or not at all
Muscle Fiber Types
Type1: Slow twitch, Produce less force; fatigue slower
Type 2: Fast twitch, produces greater forces, fatigue faster
neuromuscular concepts
Number of muscle fibers recruited
Frequency of motor unit activation
recruitment of motor units containing fast twitch fibers
muscle fibers that are at optimal length
action potential-electrical signal needed for motor unit to fire
subthreshold stimulus-when stimulus is not strong enough to cause action
Threshold stimulus-when stimulus is strong enough to cause action
Phases of a single muscle contraction/twitch
1. stimulus is received
2. Latent period-few milliseconds
3. Contraction phase- lasts about 40 milliseconds
4. Relaxation phase- lasts 50 milliseconds
Muscle length-tension relationship
´A “pulling” force
´Tension either passive by external forces or active by internal forces
´Passive tension
´As muscle is stretched beyond normal resting length
´Active tension
Dependent on number of motor units & fibers recruitment
Dependent on length of the muscle
Greatest amount of AT is developed when muscle is stretched between 100%-130% of resting length
Decrease in AT when muscle is 50%-60% of resting length
Muscle force-velocity relationship
Rate of length change is related to amount of force
With low resistance, muscle contracts at high velocity
With high resistance, muscle contracts at low velocity
With max resistance, muscle velocity is zero (isometric contraction)
As resistance increases more, the muscle begins to lengthen slowly; resistance/gravity wins
As resistance is at max, muscle will result in uncontrollable lengthening, or dropping of the load
Aggregate Muscle Action
Muscles work in groups rather than independently to achieve a given joint motion.
How are muscles named?
Shape
Size
Number of division
Directions of its fibers
Location
Points of attachment
Action
Action and shape
Action and size
Shape and location
location and attachment
location and number of divisions
Anterior/ Posterior view Superficial and deep muscles
See pic
Parallel Muscles
fibers arranged parallel to length of muscle. Generally will produce greater range of movement than similar size muscles with a pennate arrangement
Parallel Muscles: Flat
Muscles are usually thin and broad, originating from broad, fibrous, sheetlike aponeuroses that allow them to spread their forces over a broad area.
Ex: rectus abdominis and external oblique
Parallel Muscles: Fusiform
muscles are spindle-shaped with a central belly that tapers to tendons on each end; this allows them to focus their power on small, bony targets.
Ex: brachialis and brachioradials
Parallel Muscles: Strap Muscles
are more uniform in diameter with essentially all their fibers arranged in a long parallel manner. Enables a focusing of power on small, bony targets.
Ex: Sartorius
Parallel Muscles: Radiate
Muscles are also sometimes described as being triangular, fan-shaped, or convergent. They have the combined arrangement of flat and fusiform muscles, in that they originate on a broad surface or an aponeurosis and converge onto a tendon.
Ex: include the pectoralis major and trapezius
Parallel Muscles: Sphincter
circular muscles are technically endless strap muscles that surround openings and function to close them upon contraction.
Ex: orbicularis oris, surrounding the mouth.
Pennate Muscles
categorized on the basis of the exact arrangement between the fibers and the tendons
Pennate Muscle: Unipennate
fibers run obliquely from a tendon on one side only.
Ex: biceps femoris, extensor digitorum longus, and tibialis posterior
Pennate Muscle: Bipennate
Muscle fibers run obliquely from a central tendon on both sides
Ex: Rectus femoris ad flexor hallucis longus
Pennate Muscle: Multipennate
Muscles have several tendons with fibers running diagonally between them
Ex: Deltoid
Four Muscle tissue properties related to ability to produce force effecting movement about joints
Irritability/ Excitability: being sensitive or responsive to chemical, electrical, or mechanical stimuli.
Contractility: ability of muscle to contract and develop tension or internal force against resistance when stimulated.
Extensibility: ability of muscle to be passively stretched beyond its normal resting length.
Elasticity: ability of muscle to return to its original resting length following stretching
Intrinsic
Pertaining usually to muscles within or belonging solely to the body part on which they act
Ex: Small intrinsic muscle found within hands
Extrinsic
Pertaining usually to muscles that arise or orginate outside (proximal to) the body part on which they act.
Action
is the specific movement of the joint resulting from a concentric contraction of a muscle that crosses the joint.
Innervation
occurs in the segment of the nervous system responsible for providing a stimulus to muscle fibers within a specific muscle or portion of a muscle. A particular muscle may be innervated by more than one nerve, and a particular nerve may innervate more than one muscle or portion of a muscle
Amplitude
is the range of muscle fibers length between maximal and minimal lengthening
Gaster (belly or body)
is the central, fleshy portion of the muscle. Generally increases in diameter as the muscle contracts.
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Lernkarten
Aggregate Muscle Action
Muscles work in groups rather than independently to achieve a given joint motion.
How are muscles named?
Shape
Size
Number of division
Directions of its fibers
Location
Points of attachment
Action
Action and shape
Action and size
Shape and location
location and attachment
location and number of divisions
Anterior/ Posterior view Superficial and deep muscles
See pic
Parallel Muscles
fibers arranged parallel to length of muscle. Generally will produce greater range of movement than similar size muscles with a pennate arrangement
Parallel Muscles: Flat
Muscles are usually thin and broad, originating from broad, fibrous, sheetlike aponeuroses that allow them to spread their forces over a broad area.
Ex: rectus abdominis and external oblique
Parallel Muscles: Fusiform
muscles are spindle-shaped with a central belly that tapers to tendons on each end; this allows them to focus their power on small, bony targets.
Ex: brachialis and brachioradials
Parallel Muscles: Strap Muscles
are more uniform in diameter with essentially all their fibers arranged in a long parallel manner. Enables a focusing of power on small, bony targets.
Ex: Sartorius
Parallel Muscles: Radiate
Muscles are also sometimes described as being triangular, fan-shaped, or convergent. They have the combined arrangement of flat and fusiform muscles, in that they originate on a broad surface or an aponeurosis and converge onto a tendon.
Ex: include the pectoralis major and trapezius
Parallel Muscles: Sphincter
circular muscles are technically endless strap muscles that surround openings and function to close them upon contraction.
Ex: orbicularis oris, surrounding the mouth.
Pennate Muscles
categorized on the basis of the exact arrangement between the fibers and the tendons
Pennate Muscle: Unipennate
fibers run obliquely from a tendon on one side only.
Ex: biceps femoris, extensor digitorum longus, and tibialis posterior
Pennate Muscle: Bipennate
Muscle fibers run obliquely from a central tendon on both sides
Ex: Rectus femoris ad flexor hallucis longus
Pennate Muscle: Multipennate
Muscles have several tendons with fibers running diagonally between them
Ex: Deltoid
Four Muscle tissue properties related to ability to produce force effecting movement about joints
Irritability/ Excitability: being sensitive or responsive to chemical, electrical, or mechanical stimuli.
Contractility: ability of muscle to contract and develop tension or internal force against resistance when stimulated.
Extensibility: ability of muscle to be passively stretched beyond its normal resting length.
Elasticity: ability of muscle to return to its original resting length following stretching
Intrinsic
Pertaining usually to muscles within or belonging solely to the body part on which they act
Ex: Small intrinsic muscle found within hands
Extrinsic
Pertaining usually to muscles that arise or orginate outside (proximal to) the body part on which they act.
Action
is the specific movement of the joint resulting from a concentric contraction of a muscle that crosses the joint.
Innervation
occurs in the segment of the nervous system responsible for providing a stimulus to muscle fibers within a specific muscle or portion of a muscle. A particular muscle may be innervated by more than one nerve, and a particular nerve may innervate more than one muscle or portion of a muscle
Amplitude
is the range of muscle fibers length between maximal and minimal lengthening
Gaster (belly or body)
is the central, fleshy portion of the muscle. Generally increases in diameter as the muscle contracts.
Tendon
are tough yet flexible bands of fibrous connective tissue, often cordlike in appearance that connect muscles to bones and other structures. Transmit the force generated by the contracting muscle to the bone.
Aponeurosis
is a tendinous expansion of dense fibrous connective tissue that is sheet-orribbonlike in appearance and resembles a flattened tendon. Serve as a fascia to bind muscles together or as a means of connecting muscle to bone
Fascia
is a sheet or band of fibrous connective tissue that envelopes, separates, or binds together parts of the body such as muscles, organs and other soft-tissue structures of the body.
Origin
from a structural perspective, the proximal attachment of a muscle or the part that attaches closest to the midline or center of the body is usually considered to be the origin. Lease movable part or attachment of the muscle
Insertion
structurally the distal attachment, or part that attaches farthest from the misline or center of the body. The most movable part.
Isometric Contraction
Muscle tension developed but angle remains constant
static contractions
Concentric
involve muscle developing active tension as it shortens and occur when the muscles develops enough force to overcome the applied resistance. Are used to accelerate the movement of a body segment from a lower speed to a higher speed.
Eccentric contraction
involve the muscle lengthening under active tension and occur when the muscle gradually lessens in tension to control the descent of resistance. Weight of resistance may be thought of as overcoming the muscle contraction, but not tp the point that muscle cannot control the descending movement.
Isokinetics
type of dynamic exercise usually using concentric and/ or eccentric muscle contractions in which the speed (or velocity) of movement is constant and muscular contraction (ideally, maximum contraction) occurs throughout the movement.
Agonist Muscles
when contracting concentrically cause join motion through s specified plane of motion.
known as primary movers
Antagonist Muscles
located on opposite side from agonist
contra-lateral muscles
have the opposite concentric action
work to relax & lengthen while agonists contract & shorten
Stanilizers/ Fixators
surround joint or body part
contract to stabilize the area to enable another limb or body segment to exert force & move
Ex: In biceps curl the muscles of the scapula and glenohumeral joint must contract in order to maintain the shoulder complex and humerus in relatively static positition so biceps brachii can more effectively perform the curls.
Synergist/Assisters
assist in action of agonists
not necessarily prime movers for the action
known as guiding muscles
Ex. Biceps brachii during shoulder flexion
Helping synergists
have action in common but also have actions antagonistic to each other.
help another muscle move the joint in desired manner and at same time prevent undesired actions.
True Synergists
contract to prevent an undesired joint action of the agonist and have no direct effect on the agonist action
Neutralizers
Counteract/ neutralize the action of another muscle to prevent undesirable movements
Compensation
contract to resist specific actions of other muscles
´Ex. Triceps brachii neutralizes flexion action of biceps brachii during supination
Lines of Pull
Consider the following about muscles:
Know muscle’s origin & insertion
Where is it located?
What direction does it run from & to in the body?
Know muscle’s actions at specific joint
Central Nervous System (CNS)
1. Cerebral Cortex- highest level of control, provides creation of voluntary motion as aggregate, not primary action
2.Basal Ganglia: controls maintenance of postures & equilibrium, controls learned movements such as driving a car, controls sensory integration for balance and rythmic activities.
3. Cerebellum- sensory impulses, provides feedback from motion, and assists in refinement of motion
4. Brain stem- integrates activity through excitation and inhibition of desired neuromuscular functions, functions of maintaining a wakeful state.
5. Spinal Cord- common pathway between CNS & PNS, integrates simple and complex spinal reflexes
Peripheral Nervous System (PNS)
Sensory (afferent) nerves-bring impulses from receptors in the skin, joints, muscles, and other peripheral aspects of body to the CNS
Motor (efferent) nerves- carry impulses to the outlying regions of the body
Cranial nerves – 12 pairs
Motor & Sensory
Spinal nerves- named for location of vertebral column
Dermatome- area of skin innervated by spinal nerve/s
Myotome – muscle/group innervated by spinal nerve/s that performs a motor function
Reflexes
Cervical Nerve Root 1
C1: Dermatome afferent (sensory)- Touch: Vertex of skull
Myotome efferent (motor) upper neck muscles
Reflexes: None
Functional application: Capital flexion and extension
