ES - Basic Principles of Biomech. Regarding... - Roles of Muscles in Movement

Question 1

Origin and Insertion attachments

Answer 1

O: proximal/stationary; toward center of body
I: distal/mobile; away from center of body
Ex. iliacus muscle during straight-leg sit-up
O: femur b/c it’s immobile
I: pelvis

Question 2

Fibrous attachments

Answer 2

Tendons

blend into and are continuous w/ both muscle sheaths and connective tissue surrounding bone.

Question 3

Types of Muscles (5)

Answer 3

Agonist
Antagonist
Synergist
Neutralizers
Stabilizers (fixators)

Question 4

Agonist

Answer 4

aka prime mover

muscles most directly involved in bringing about movement.

Question 5

Antagonist

Answer 5

work on opposite of joint and have opposite concentric action from agonists.
Muscles that slow down or stop movement.
Assists in joint stabilization and in stopping the limb toward the end of a fast movement, thereby protecting ligamentous and cartilaginous joints from destructive forces.

Question 6

Synergist

Answer 6

muscles that assist indirectly to the action of agonist muscles.
Assist in refined movements.
ex. muscles that stabilize the scapula during upper arm movement.

Question 7

Neutralizers

Answer 7

counteract or neutralize the action of other muscles to prevent undesirable movements such as inappropriate muscle substitutions.

ex. when only supination action of the biceps brachii is desired, the triceps brachii contracts to neutralize the flexion action of the biceps brachii.
ex2. bicep hammer curl when only flexion is desired. When the biceps brachii contracts, it normally attempts to both flex the elbow and supinate the forearm.

Question 8

Stabilizers

Answer 8

aka fixators
Surround the joint or body part and contract to fixate or stabilize the area to enable another limb or body segment to exert force and move (aka proximal stabilization).
Essential in establishing firm base for distal joints to work.
ex. biceps curl; muscles of scapula and glenohumeral joint must contract in order to maintain shoulder complex and humerus in a static position so the biceps brachii can effectively perform curls.

Question 9

Various roles muscles play in movement (*****)

Answer 9

a

Question 10

Roles of Muscle type in sports performance (sprinting) (****)

Answer 10

Agonist: quad muscles
Antagonist: 
Synergist
Neutralizers
Stabilizers