muscular analysis of movement chapter 14, pp.260-264 chapter 17
TRANSCRIPT
Muscular Analysis of Movement
Chapter 14, pp.260-264Chapter 17
Simple Joint System
System Level Function
Force & torque production for joint mobility and stability through rotation and translation of bones (segments)
Muscle ActionsMuscle Coordination (Synergy)
Related Terminology
muscle action – the development of tension (force) by a muscle
functional muscle group – a group of muscles that are capable of causing a specific joint action (e.g., wrist radial deviators)
motive force (or torque) – force causing the observed movement
resistive force (or torque) – force opposing the observed movement
Types of Muscle Actions
ConcentricEccentricIsometric
Concentric
Shortens to cause movementRotational movementMechanically:
Net Muscle (Motive) Torque > Net Resistive Torque
Eccentric
Lengthens to resist, control, or slow down movement
Rotational movementMechanically:
Net Muscle (Resistive) Torque < Net Motive Torque
Isometric
Stays the same so that bone will stay fixed
No movementMechanically:
Net Muscle Torque = Other TorqueTotal Net Torque = 0
System Level: Muscle Actions
Resulting motion dependent on all torques acting about the joint (net torque)
Isometric?Eccentric?Conditions for concentric?
Muscle Coordination: Roles that Muscles Play
AgonistsAntagonistsStabilizersNeutralizers
Agonist (Mover)
The role played by a muscle acting to cause a movementPrime moversAssistant movers
Arbitrary distinction
Force development during concentric action Relaxation during eccentric action
Antagonist
The role played by a muscle acting to control movement of a body segment
against some other non-muscle force to slow or stop a movement
Force development during eccentric actionCheck ballistic movements
Relaxation during concentric action
Stabilizer
The role played by a muscle to stabilize (fixate) a body part against some other force rotary (joint) stabilizer linear (bone) stabilizer
Isometric muscle action
Neutralizer
The role played by a muscle to eliminate an unwanted action produced by an agonist Scapular or pelvic stabilization Multijoint muscles Elevation of the humerus
Muscle action varies
To perform a muscular analysis:
1. Break the skill into phases.2. Determine the joint action?3. Determine the motive force –
muscle or some other force?4. Determine the resistive force –
muscle or some other force?
To perform a muscular analysis (ID muscle actions and responsible groups):
5. Identify whether there are joints/bones that must be stabilized
6. Identify the FMG(s) that is(are) developing force the type of muscle action of the FMG(s) the roles played by the FMG(s)
7. Identify neutralization.
Example 1: Biceps CurlUp Phase Down Phase
Joint Action
Motive Force
Resistive Force
FMG Developing Force
Muscle Action
Flexion
Muscle
Weight/Gravity
Concentric
Elbow Flexors
Example 1: Biceps CurlUp Phase Down Phase
Joint Action
Motive Force
Resistive Force
FMG Developing Force
Muscle Action
Flexion
Muscle
Weight/Gravity
Concentric
Extension
Muscle
Weight/Gravity
Eccentric
Elbow FlexorsElbow Flexors
Example 1: Biceps CurlUp Phase Down Phase
Joint Action
Motive Force
Resistive Force
FMG Developing Force
Muscle Action
Flexion
Muscle
Weight/Gravity
Concentric
Extension
Muscle
Weight/Gravity
Eccentric
Elbow FlexorsElbow Flexors
Agonists: Flexors Extensors
Example 1: Biceps CurlUp Phase Down Phase
Joint Action
Motive Force
Resistive Force
FMG Developing Force
Muscle Action
Flexion
Muscle
Weight/Gravity
Concentric
Extension
Muscle
Weight/Gravity
Eccentric
Elbow FlexorsElbow Flexors
Antagonists: Extensors Flexors
Stabilization?
1. Rotary stabilization Wrist flexors
2. Linear stabilization
Neutralization?
1. To prevent scapular or pelvic movement when moving humerus or femurShoulder girdle retractorsShoulder girdle elevators
2. To prevent unwanted motion caused by multijoint musclesShoulder extensorsForearm pronators
Neutralization
3. To prevent scapular movement during elevation of the humerus
4. Other? Biceps brachii – shoulder flexion, RU
supination Brachialis – none Brachioradialis – RU motion Pronator teres – RU pronation
Summary
Movement at a single joint is possible because of the complex coordination that occurs between numerous muscles.
Therefore, all those muscles must have adequate strength to accomplish its task in a given movement.
Injury to or lack of strength in any of those muscles can result in the inability to perform the movement.
Summary
A muscular analysis allows us to identify the muscles that contribute to a movement and how they contribute to the movement.
We can then prepare conditioning & rehabilitation programs that target utilized muscles appropriately.