copyright © 2011, 2007 by mosby, inc., an affiliate of elsevier inc. all rights reserved. 1 roles...

Copyright © 2011, 2007 by Mosby, Inc., an affiliate of Elsevier Inc. All rights reserved.

1

Roles of MusclesFrom the books of Joseph E. Muscolino, DC

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

1


2

Objectives• Define the key terms of this chapter and state the meanings of Define the key terms of this chapter and state the meanings of

the word origins of this chapter.the word origins of this chapter.• Describe the relationship between the role that a muscle plays Describe the relationship between the role that a muscle plays

and the action in question.and the action in question.• Compare and contrast the roles of mover and antagonist. Compare and contrast the roles of mover and antagonist. • Discuss the concept of cocontraction. Discuss the concept of cocontraction.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

2


3

ObjectivesObjectives

• State the muscle that is working during the action in question.• Describe the relationship between gravity and joint actions. • Explain the application of tight antagonists to restricted joint

motion.• Compare and contrast the roles of fixator and neutralizer.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

3


4

Mover MusclesMover Muscles• Movers: muscles that can do the action in questionMovers: muscles that can do the action in question• Can shorten in two ways:Can shorten in two ways:

• Concentrically contract and shortenConcentrically contract and shorten• Relax and shortenRelax and shorten

• For every joint action, a functional group of movers can contract For every joint action, a functional group of movers can contract to make the action happen.to make the action happen.


5

Mover Muscles (cont’d.)Mover Muscles (cont’d.)• Most powerful mover = prime moverMost powerful mover = prime mover• Other movers = assistant moversOther movers = assistant movers• Movers are also known as agonists.Movers are also known as agonists.

Figure 13-1


6

Mover Muscles (cont’d.)Mover Muscles (cont’d.)

Figure 13-1

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

6


7

Antagonist MusclesAntagonist Muscles

• Antagonists do the opposite action of the action in question.Antagonists do the opposite action of the action in question.• Can lengthen in two ways:Can lengthen in two ways:

• Eccentrically contract and lengthenEccentrically contract and lengthen• Relax and lengthenRelax and lengthen

• Sometimes called contralateral muscle (opposite side)Sometimes called contralateral muscle (opposite side)


8

Antagonist Muscles (cont’d.)Antagonist Muscles (cont’d.)• Most powerful antagonist = prime antagonistMost powerful antagonist = prime antagonist

Figure 13-2


9

Antagonist Muscles (cont’d.)Antagonist Muscles (cont’d.)

Figure 13-2

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

9


10

Antagonist Muscles (cont’d.Antagonist Muscles (cont’d.)

• Contraction: when the agonist and antagonist Contraction: when the agonist and antagonist contract at the same timecontract at the same time• Not considered healthyNot considered healthy• The same as pressing gas and brake pedals The same as pressing gas and brake pedals

simultaneouslysimultaneously


11

Determining the “Muscle Determining the “Muscle That Is Working”That Is Working”

• Muscle that is working = muscle that contracts during the Muscle that is working = muscle that contracts during the action in questionaction in question

• Easiest way is to examine gravity’s role in the action in Easiest way is to examine gravity’s role in the action in questionquestion

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

11


12

Determining the “Muscle That Is Determining the “Muscle That Is Working” (cont’d.)Working” (cont’d.)

• Three general rules:Three general rules:• Upward movements, movers work and antagonists relaxUpward movements, movers work and antagonists relax• Horizontal movements, movers work and antagonists Horizontal movements, movers work and antagonists

relaxrelax• Downward movements, antagonists work and movers Downward movements, antagonists work and movers

relaxrelax

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

12


13


Figure 13-3

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

13


14


Figure 13-3

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

14


15

Stopping Unwanted Actions of the Stopping Unwanted Actions of the “Muscle That Is Working”“Muscle That Is Working”

• Fixators and neutralizers both stop unwanted actions of Fixators and neutralizers both stop unwanted actions of working muscleworking muscle• Fixators stop action at fixed attachmentFixators stop action at fixed attachment• Neutralizers stop action at mobile attachmentNeutralizers stop action at mobile attachment

• Example: flexion of the fingers into a fistExample: flexion of the fingers into a fist

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

15


16

ObjectivesObjectives• Describe the general concept of the relationship Describe the general concept of the relationship

between fixators and neutralizers and the muscle between fixators and neutralizers and the muscle that is working. that is working.

• Give an example of a fixator and a neutralizer Give an example of a fixator and a neutralizer relative to a specific joint action. relative to a specific joint action.

• State the step-by-step method for determining State the step-by-step method for determining fixators and neutralizers relative to a specific fixators and neutralizers relative to a specific joint action. joint action.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

16


17

Fixator MusclesFixator Muscles• Fixators: stop unwanted action at the Fixators: stop unwanted action at the

fixed attachment of muscle that is fixed attachment of muscle that is workingworking

• Also known as stabilizersAlso known as stabilizers• Contract isometricallyContract isometrically

Figure 13-4

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

17


18

Fixator Muscles (cont’d.)Fixator Muscles (cont’d.)

Figure 13-4 Figure 13-5

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

18In the illustration on the right, the posterior deltoid acts as a fixator of the arm by In the illustration on the right, the posterior deltoid acts as a fixator of the arm by creating a force of extension on the arm at the shoulder joint. This prevents creating a force of extension on the arm at the shoulder joint. This prevents the biceps brachii from flexing the arm at the shoulder joint. the biceps brachii from flexing the arm at the shoulder joint.


19

Fixator Muscles (cont’d.)Fixator Muscles (cont’d.)

Figure 13-6

●● Which muscle is acting as the fixator in this figure?Which muscle is acting as the fixator in this figure?

The rectus abdominis.The rectus abdominis.

●● Why?Why?

It prevents the TFL from anteriorly tilting the pelvis.It prevents the TFL from anteriorly tilting the pelvis. ology of the musculoskeletal system: foundations for physical rehabilitation, ed 2, St Louis, 2010, Mosby

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

19


20

Concept of Fixation and Concept of Fixation and Core StabilizationCore Stabilization

• Mobility (phasic) muscles: larger, longer, more superficialMobility (phasic) muscles: larger, longer, more superficial• Postural stabilization (tonic) muscles: smaller, deeper, closer Postural stabilization (tonic) muscles: smaller, deeper, closer

to jointsto joints• Core stabilization, strength, and efficiency of movementCore stabilization, strength, and efficiency of movement• Core stabilization and spinal healthCore stabilization and spinal health

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

20


21

Concept of Fixation and Core Concept of Fixation and Core Stabilization (cont’d.)Stabilization (cont’d.)

If we stabilize our core’s axial body, then we can channel all the strength of our muscles’ contractions toward moving our extremities.

Modeled from Neumann DA: Kinesiology of the musculoskeletal system: foundations for physical rehabilitation, ed 2, St Louis, 2010, Mosby

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

21


22

Concept of Fixation and Core Concept of Fixation and Core Stabilization (cont’d.)Stabilization (cont’d.)

Figure 13-8

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

22If the vertebrae in this scenario are not fixed, then they will move every time the arm abducts. This can eventually result in excessive wear and tear and therefore damage to the spine.


23

• Neutralizers stop unwanted action at the mobile Neutralizers stop unwanted action at the mobile attachment of the muscle that is working.attachment of the muscle that is working.• They create a contraction force equal in strength but They create a contraction force equal in strength but

opposite in direction to the force of the unwanted opposite in direction to the force of the unwanted action.action.

Neutralizer MusclesNeutralizer Muscles

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

23

● There are three cardinal planes: sagittal, frontal, and transverse. If There are three cardinal planes: sagittal, frontal, and transverse. If we assume that the desired action occurs in one of these planes, we we assume that the desired action occurs in one of these planes, we should also recognize that undesired actions might occur in the other should also recognize that undesired actions might occur in the other two, were it not for the presence of neutralizers. two, were it not for the presence of neutralizers.


24

Neutralizer Muscles (cont’d.)Neutralizer Muscles (cont’d.)

Figure 13-9

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

24

In B (on the right), why is the sternocleidomastoid (SCM) a In B (on the right), why is the sternocleidomastoid (SCM) a neutralizer?neutralizer?

It is a neutralizer because it cancels out unwanted actions of It is a neutralizer because it cancels out unwanted actions of the right levator scapulae. (Neck flexion cancels out neck extension, the right levator scapulae. (Neck flexion cancels out neck extension, and left rotation of the neck cancels out right rotation of the neck.) and left rotation of the neck cancels out right rotation of the neck.)


25

Neutralizer Muscles (cont’d.)Neutralizer Muscles (cont’d.)

Figure 13-10 Figure 13-11

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

25Which muscle is the neutralizer in the illustration on the left?

The pronator teres is the neutralizer because its action of pronation of the forearm at the radioulnar joints cancels out the biceps brachii’s action of supination of the forearm at the radioulnar joints.


26

Step-by-Step Method for Step-by-Step Method for Determining Fixators and Determining Fixators and NeutralizersNeutralizers

• Determine the action in question.Determine the action in question.• Determine the muscle that is working and its role.Determine the muscle that is working and its role.• Determine the fixed and mobile attachments.Determine the fixed and mobile attachments.• List all actions of the muscle that is working, and state List all actions of the muscle that is working, and state

whether the actions are desired or undesired.whether the actions are desired or undesired.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

26


27

Step-by-Step Method for Determining Step-by-Step Method for Determining Fixators and Neutralizers (cont’d.)Fixators and Neutralizers (cont’d.)

• Determine the action of each fixator at the fixed Determine the action of each fixator at the fixed attachment.attachment.

• Choose a muscle that can do the action determined for Choose a muscle that can do the action determined for each fixator.each fixator.

• Determine the action of each neutralizer at the mobile Determine the action of each neutralizer at the mobile attachment.attachment.

• Choose a muscle that can do the action determined for Choose a muscle that can do the action determined for each neutralizer.each neutralizer.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

27


28

Step-by-Step Method for Determining Step-by-Step Method for Determining Fixators and Neutralizers (cont’d.)Fixators and Neutralizers (cont’d.)

Figure 13-12

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

28


29


• Describe the role of a support muscle.Describe the role of a support muscle.• Explain the two ways in which a synergist can be Explain the two ways in which a synergist can be

defined. defined. • Compare and contrast synergists and antagonists for a Compare and contrast synergists and antagonists for a

given joint action.given joint action.• Explain the concept of coordination as it relates to the Explain the concept of coordination as it relates to the

role of muscles.role of muscles.• Describe the possible clinical effects of isometric Describe the possible clinical effects of isometric

contractions. contractions.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

29


30


• Define and give an example of a 2nd-order fixator. Define and give an example of a 2nd-order fixator. • Explain why it is difficult to isolate a specific muscle Explain why it is difficult to isolate a specific muscle

contraction; further, explain and give an example of how contraction; further, explain and give an example of how muscle contractions tend to spread through the body. muscle contractions tend to spread through the body.

• Discuss and give an example of the concept of coupled Discuss and give an example of the concept of coupled actions in the body. actions in the body.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

30


31

Support MusclesSupport Muscles

• Hold another part of the body in position while the Hold another part of the body in position while the action in question is occurringaction in question is occurring

• Do not work directly at the jointDo not work directly at the joint• Oppose the force of gravity on a body partOppose the force of gravity on a body part• Contract isometricallyContract isometrically

● Support muscles usually work far away from the joint Support muscles usually work far away from the joint where an action is occurring. where an action is occurring.


32

Support Muscles

Figure 13-13Figure 13-14

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

32

The left-sided erector spinae musculature The left-sided erector spinae musculature supports this action.supports this action.

Its force of left lateral flexion of the trunk at the spinal joints prevents Its force of left lateral flexion of the trunk at the spinal joints prevents the trunk from falling into right lateral flexion of the trunk at the spinal the trunk from falling into right lateral flexion of the trunk at the spinal joints.joints.


33

Synergists• Synergists: muscles or forces that work with the Synergists: muscles or forces that work with the

muscle that is contractingmuscle that is contracting• Example #1: Biceps brachii and pronator teresExample #1: Biceps brachii and pronator teres

Figure 13-15


34

SynergistsSynergists

• Example #2: Right external Example #2: Right external abdominal oblique and left abdominal oblique and left internal abdominal obliqueinternal abdominal oblique

Figure 13-15

In the sagittal plane, these muscles are In the sagittal plane, these muscles are synergists. In the frontal plane, however, synergists. In the frontal plane, however, they are antagonists. they are antagonists.


35

Coordinating Muscle RolesCoordinating Muscle Roles

• Muscles rarely act in isolation.Muscles rarely act in isolation.• A number of muscles may contract for any given joint action.A number of muscles may contract for any given joint action.• Coordination is the co-ordering of muscles in the body in Coordination is the co-ordering of muscles in the body in

their various roles to create smooth and efficient movementtheir various roles to create smooth and efficient movement.

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

35


36


• Clinical effects of isometric contractionsClinical effects of isometric contractions• Close off veins for the entire lengthClose off veins for the entire length

of contractionof contraction• Buildup of toxic waste productsBuildup of toxic waste products• Waste products irritate nervesWaste products irritate nerves

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

36


37

Coordinating Muscle RolesCoordinating Muscle Roles• 2nd-order fixators2nd-order fixators

• Fixators that fix attachments Fixators that fix attachments of fixator or neutralizer of fixator or neutralizer musclesmuscles

Figure 13-16

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

37

One way to explore the complexity of One way to explore the complexity of coordination is to lift a heavy weight in coordination is to lift a heavy weight in your right hand (as shown in the your right hand (as shown in the illustration) and slowly palpate the illustration) and slowly palpate the pronator teres, biceps brachii, posterior pronator teres, biceps brachii, posterior deltoid, and left erector spinae. You will deltoid, and left erector spinae. You will be able to feel each of these muscles as be able to feel each of these muscles as they work in concert to lift the weight. they work in concert to lift the weight.


38


Figure 13-17

04

/18

/23

TC

CD

MA

SS

AG

E T

HE

RA

PY

P

RO

GR

AM

MS

SG

20

14

K

INE

SIO

LO

GY

38

In the soccer scenario, In the soccer scenario, what is the role of the what is the role of the support muscle?support muscle?

It is keeping the player It is keeping the player from falling to the from falling to the ground.ground.


39

Coupled ActionsCoupled Actions• Two separate joint actions that must occur simultaneouslyTwo separate joint actions that must occur simultaneously

Figure 13-18

● Abduction of the arm 180 degrees relative to the trunk really consists of Abduction of the arm 180 degrees relative to the trunk really consists of two separate coupled joint actions.two separate coupled joint actions.

●● What are they?What are they?The two separate coupled joint actions are abduction of the arm at the The two separate coupled joint actions are abduction of the arm at the shoulder joint and upward rotation of the scapula at the scapulocostal shoulder joint and upward rotation of the scapula at the scapulocostal joint.joint.

copyright © 2011, 2007 by mosby, inc., an affiliate of elsevier inc. all rights reserved. 1 roles...

Documents

mover muscles movers

question movers

opposite action

affiliate of elsevier

assistant movers movers

prime mover

powerful mover

roles of mover