EXAM 2 Flashcards
Role, Characteristics and Importance of Agonist Muscles
Role: do the main work when the body moves (PRIME MOVERS)
Characteristic: may produce concentric and eccentric contractions
Importance: allow for joint movement
A is for Active Muscle = they are the main players
Role, Characteristics and Importance of Antagonist Muscles
Role: Produce opposite joint movements to agonists
Characteristics: Located on opposite side of joint from agonist
Importance: Main function is to relax and allow agonist muscles to produce movement
Antagonist = “Opposite” action; when you do a bicep curl biceps contract (agonist) and triceps relax (antagonist)
Role, Characteristics and Importance of Neutralizer Muscles
Role: help stop unwanted movements when you’re performing a certain movement
Characteristics:
Importance: Contract to resist specific actions of other muscles
Neutralizer muscles are the “bodyguards” aren’t the celebrities of movement but the protector
Neutralizer = “No Extra Movements”
Role, Characteristics and Importance of Stabilizer Muscles
Role: keep the body steady and in the right position. (Core during push-ups)
Characteristics: Surround joint or body part
Importance: Establishes a firm base for the distal joints to carry out movements
Support team or backstage crew = make sure everything runs smoothly but are not in the spotlight
Role, Characteristics and Importance of Synergist Muscles
Role: help the agonist do their job more effectively
Characteristics: Assist agonist muscles
Importance: allows for a smooth muscles movement
Synergist = sidekick; support and assist the main muscle in doing its work
What are Uniarticular Muscles?
Muscles that cross and act directly only on the joint that they cross; move one joint at a time
EX: Brachialis can only pull the humerus and ulna closer together
What are Biarticular Muscles?
Muscles that cross and act on two different joints; move two joints at a time
EX: quadriceps muscles
What are Multiarticular Muscles?
Muscles that act on three or more joints between their origin and insertion crossing multiple joint; move multiple joints at a time
EX: Finger flexors
What are the characteristics/advantages of Biarticular and Multiarticular Muscles over Uniarticular Muscles?
Two advantages:
1. Cause and/or control motion at more than one joint
2. Maintain a relatively constant length due to “shortening” at one joint and “lengthening” at another joint”
What is Active Insufficiency?
Active Insufficiency is reached when the muscle becomes shortened to the point that it can not generate or maintain active tension
- the muscle cannot shorten any further
rubber band stretched completely
What is Passive Insufficiency?
Passive insufficiency is reached when the opposing muscle becomes stretched to the point where it can no longer lengthen and allow movement
What are the differences between Active and Passive Insufficiency?
Active insufficiency is when an actively participating muscle becomes maximally short
Passive insufficiency is when a muscle that is not actively participating becomes maximally stretched
What is Proprioception?
The body’s ability to sense and know where its parts are and what they are doing, even when you’re not looking at them
”proprio-“ = self; “ception” = perception
What is Kinesthesis?
The ability to sense your body’s movement and how you body parts are moving through space
Kinesis = movement; -thesis = sense
What is the role of Muscle Spindles?
Leads to muscle contraction; the springs of the muscles
Where are Muscles Spindles located?
Concentrated primarily in muscle belly between the fibers; springs within a mattress
What is the concept behind the Stretch Reflex?
More sudden the stretch, the more significant the reflexive contraction
“I’m stretching too fast! I need to contract and protect myself!”
the body’s automatic “bounce-back” reaction
What is the role of the Golgi Tendon Organ?
GTO protects us from an excessive contraction by causing its muscle to relax
The GTO is a “safety brake” for the muscles. When your muscles are working hard and getting too much tension, the GTO pulls the brakes to keep you from injuring yourself
Where is the Golgi Tendon Organ located?
Found in the tendon close to muscle tendon junction
Located in your tendons-the stretchy parts of your body that connect your muscles to your bones
How does the Golgi Tendon Organ help the muscle to relax?
- When your muscles contract, your tendons stretch and feel the tension
- This activates the GTO which can sense how much force is being put on the tendon; sends impulse to CNS
- CNS causes muscles to relax by activating antagonists are protective mechanism
What is Reciprocal Innervation or Inhibition?
Reciprocal Innervation is like a team effort: when one muscle is active, the other takes a break. This helps us move easily and prevents our muscles from fighting against each other!
a vacation for muscles
What is the role of Reciprocal Innervation in muscle contraction?
- It makes sure the muscles don’t get in each other’s way by letting the muscles work together to make movements easy and controlled
- It prevents injury by making sure that when one muscle is working, the other isn’t being forced to do the opposite action at the same time
How does Reciprocal Innervation operate?
- It happens automatically: the brain sends messages to muscles being used - telling one muscle to contract and the other to relax - without having to think about it.
What is the All or None Principle?
Regardless of number, individual muscle fibers within a given motor unit will either fire and contract maximally or not at all
Like a light switch: when you flip the light switch, the light is either on or off; there is no “half-contraction”
What is a motor unit?
A motor unit is a group of things in your body that work together to help you move; a team made up of :
- THE COACH: a motor neuron (sends messages from the brain to the muscles) that tells the players (muscle fibers) what to do
- THE PLAYERS: muscle fibers who do the work
What is the importance of the Shoulder Girdle?
- Stabilize scapula during shoulder joint actions
- Enhance movements of upper extremity when shoulder goes through extreme ranges of motion (EX: 180 degrees of shoulder abduction= 120 degrees of glenohumeral abduction + 60 degrees of upward rotation at shoulder girdle)
What are the three Shoulder Girdle Joints?
Sternoclavicular Joint, Acromioclavicular Joint and Scapulo-thoracic Joint
What bones are involved in the Sternoclavicular Joint?
Sternum + Medial End of Clavicle
What movements occur at the Sternoclavicular Joint?
Protraction, Retraction, Elevation and Depression
What bones are involved in the Acromioclavicular Joint?
Acromion process of the scapula + Lateral end of clavicle
What movements occur at the Acromioclavicular Joint?
Allows gliding and rotational motion of the scapula
Posterior Tilt (Shoulder Hyperflexion)
Anterior Tilt (Shoulder Hyperextension)
Lateral Tilt or Internal Rotation (Shoulder Abduction)
Medial Tilt or External Rotation (Shoulder adduction)
What bones are involved in the Scapulo-thoracic Joint?
Scapula + Posterior part of the ribcage
