1 / 39

Roles of Muscles

Roles of Muscles. From the books of Joseph E. Muscolino, DC. Objectives. Define the key terms of this chapter and state the meanings of the word origins of this chapter. Describe the relationship between the role that a muscle plays and the action in question.

basil-johns
Download Presentation

Roles of Muscles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Roles of Muscles From the books of Joseph E. Muscolino, DC TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  2. Objectives • Define the key terms of this chapter and state the meanings of the word origins of this chapter. • Describe the relationship between the role that a muscle plays and the action in question. • Compare and contrast the roles of mover and antagonist. • Discuss the concept of cocontraction. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  3. Objectives • 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. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  4. Mover Muscles • Movers: muscles that can do the action in question • Can shorten in two ways: • Concentrically contract and shorten • Relax and shorten • For every joint action, a functional group of movers can contract to make the action happen.

  5. Mover Muscles (cont’d.) • Most powerful mover = prime mover • Other movers = assistant movers • Movers are also known as agonists. Figure 13-1

  6. Mover Muscles (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-1

  7. Antagonist Muscles • Antagonists do the opposite action of the action in question. • Can lengthen in two ways: • Eccentrically contract and lengthen • Relax and lengthen • Sometimes called contralateral muscle (opposite side)

  8. Antagonist Muscles (cont’d.) • Most powerful antagonist = prime antagonist Figure 13-2

  9. Antagonist Muscles (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-2

  10. Antagonist Muscles (cont’d.) • Contraction: when the agonist and antagonist contract at the same time • Not considered healthy • The same as pressing gas and brake pedals simultaneously

  11. Determining the “Muscle That Is Working” • Muscle that is working = muscle that contracts during the action in question • Easiest way is to examine gravity’s role in the action in question TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  12. Determining the “Muscle That Is Working” (cont’d.) • Three general rules: • Upward movements, movers work and antagonists relax • Horizontal movements, movers work and antagonists relax • Downward movements, antagonists work and movers relax TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  13. Determining the “Muscle That Is Working” (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-3

  14. Determining the “Muscle That Is Working” (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-3

  15. Stopping Unwanted Actions of the “Muscle That Is Working” • Fixators and neutralizers both stop unwanted actions of working muscle • Fixators stop action at fixed attachment • Neutralizers stop action at mobile attachment • Example: flexion of the fingers into a fist TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  16. Objectives • Describe the general concept of the relationship between fixators and neutralizers and the muscle that is working. • Give an example of a fixator and a neutralizer relative to a specific joint action. • State the step-by-step method for determining fixators and neutralizers relative to a specific joint action. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  17. Fixator Muscles • Fixators: stop unwanted action at the fixed attachment of muscle that is working • Also known as stabilizers • Contract isometrically TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-4

  18. Fixator Muscles (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY 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 the biceps brachii from flexing the arm at the shoulder joint. Figure 13-4 Figure 13-5

  19. Fixator Muscles (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY ● Which muscle is acting as the fixator in this figure? The rectus abdominis. ● Why? It prevents the TFL from anteriorly tilting the pelvis. ology of the musculoskeletal system: foundations for physical rehabilitation, ed 2, St Louis, 2010, Mosby Figure 13-6

  20. Concept of Fixation and Core Stabilization • Mobility (phasic) muscles: larger, longer, more superficial • Postural stabilization (tonic) muscles: smaller, deeper, closer to joints • Core stabilization, strength, and efficiency of movement • Core stabilization and spinal health TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  21. Concept of Fixation and Core Stabilization (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Modeled from Neumann DA: Kinesiology of the musculoskeletal system: foundations for physical rehabilitation, ed 2, St Louis, 2010, Mosby If we stabilize our core’s axial body, then we can channel all the strength of our muscles’ contractions toward moving our extremities.

  22. Concept of Fixation and Core Stabilization (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY If 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. Figure 13-8

  23. Neutralizer Muscles • Neutralizers stop unwanted action at the mobile attachment of the muscle that is working. • They create a contraction force equal in strength but opposite in direction to the force of the unwanted action. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY ● There are three cardinal planes: sagittal, frontal, and transverse. If we assume that the desired action occurs in one of these planes, we should also recognize that undesired actions might occur in the other two, were it not for the presence of neutralizers.

  24. Neutralizer Muscles (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY In B (on the right), why is the sternocleidomastoid (SCM) a neutralizer? It is a neutralizer because it cancels out unwanted actions of the right levator scapulae. (Neck flexion cancels out neck extension, and left rotation of the neck cancels out right rotation of the neck.) Figure 13-9

  25. Neutralizer Muscles (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Which 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. Figure 13-10 Figure 13-11

  26. Step-by-Step Method for Determining Fixators and Neutralizers • Determine the action in question. • Determine the muscle that is working and its role. • Determine the fixed and mobile attachments. • List all actions of the muscle that is working, and state whether the actions are desired or undesired. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  27. Step-by-Step Method for Determining Fixators and Neutralizers (cont’d.) • Determine the action of each fixator at the fixed attachment. • Choose a muscle that can do the action determined for each fixator. • Determine the action of each neutralizer at the mobile attachment. • Choose a muscle that can do the action determined for each neutralizer. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  28. Step-by-Step Method for Determining Fixators and Neutralizers (cont’d.) TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-12

  29. Objectives • Describe the role of a support muscle. • Explain the two ways in which a synergist can be defined. • Compare and contrast synergists and antagonists for a given joint action. • Explain the concept of coordination as it relates to the role of muscles. • Describe the possible clinical effects of isometric contractions. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  30. Objectives • Define and give an example of a 2nd-order fixator. • Explain why it is difficult to isolate a specific muscle contraction; further, explain and give an example of how muscle contractions tend to spread through the body. • Discuss and give an example of the concept of coupled actions in the body. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  31. Support Muscles • Hold another part of the body in position while the action in question is occurring • Do not work directly at the joint • Oppose the force of gravity on a body part • Contract isometrically ● Support muscles usually work far away from the joint where an action is occurring.

  32. Support Muscles TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY The left-sided erector spinae musculature supports this action. 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 joints. Figure 13-13 Figure 13-14

  33. Synergists • Synergists: muscles or forces that work with the muscle that is contracting • Example #1: Biceps brachii and pronator teres Figure 13-15

  34. Synergists • Example #2: Right external abdominal oblique and left internal abdominal oblique In the sagittal plane, these muscles are synergists. In the frontal plane, however, they are antagonists. Figure 13-15

  35. Coordinating Muscle Roles • Muscles rarely act in isolation. • A number of muscles may contract for any given joint action. • Coordination is the co-ordering of muscles in the body in their various roles to create smooth and efficient movement. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  36. Coordinating Muscle Roles • Clinical effects of isometric contractions • Close off veins for the entire lengthof contraction • Buildup of toxic waste products • Waste products irritate nerves TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY

  37. Coordinating Muscle Roles • 2nd-order fixators • Fixators that fix attachments of fixator or neutralizer muscles One way to explore the complexity of coordination is to lift a heavy weight in your right hand (as shown in the illustration) and slowly palpate the pronator teres, biceps brachii, posterior deltoid, and left erector spinae. You will be able to feel each of these muscles as they work in concert to lift the weight. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-16

  38. Coordinating Muscle Roles In the soccer scenario, what is the role of the support muscle? It is keeping the player from falling to the ground. TCCD MASSAGE THERAPY PROGRAM MSSG 2014 KINESIOLOGY Figure 13-17

  39. Coupled Actions • Two separate joint actions that must occur simultaneously ● Abduction of the arm 180 degrees relative to the trunk really consists of two separate coupled joint actions. ● What are they? The two separate coupled joint actions are abduction of the arm at the shoulder joint and upward rotation of the scapula at the scapulocostal joint. Figure 13-18

More Related