Chap 5: Muscular System Flashcards
What is a muscle origin?
where the mm starts
more stable bone which the mm moves towards
what’s the muscles insertion?
the more moveable bone which the mm is connected to
what is normal resting length?
the length of the mm when not in use
the length of the muscle when it is not shortened or lengthened - that is, when there are no forces or stresses placed upon it
what is irritability/excitability?
ability to respond to a stimulus
the ability to respond to a stimulus
what is contractility?
the mm ability to contract and generate force when it receives adequate stimulation
what is extensibility?
the mm ability to extend
the mm ability to stretch or lengthen when a force is applied
what is elasticity?
the mm ability to recoil or return to normal resting length when the stretching or shortening force is removed
what is passive tension
Stretching a muscle builds up passive tension, much like stretching a rubber band, and involves the noncontractile units of a muscle
what is active tension
Active tension comes from the contractile units and the force generated can be compared with releasing one end of a stretched rubber band.
what is tone?
Tone is the slight tension that is present in a muscle at all times, even when the muscle is resting.
Tone is a state of readiness that allows the muscle to act more easily and quickly when needed.
what is excursion?
general ability of a muscle to shorten to ½ of resting length and stretch to approximately twice as far as can be shortened
The excursion of a muscle is that distance from maximum lengthening to maximum shortening.
what is Active insufficiency?
occurs when a muscle cannot actively shorten any farther
The muscle runs out of contractile power before full joint ROM is reached
Occurs when 2-joint muscles attempt to perform full ROM at both joints
what is passive insufficiency?
occurs when a muscle cannot stretch/lengthen any farther without damage
The muscle runs out of available length before full joint ROM is reached; occurs in 2-joint muscles in general
what is Adaptive Lengthening
Poor posture can often result in a muscle being in a chronically overstretched (lengthened) state where it adopts an abnormally long resting length.
Stretching a muscle to increase it’s length
what is adaptive shortening
in situations when a muscle is left in a shortened position for a prolonged period of time without moving through its full excursion, it undergoes adaptive shortening in which the resting length and amount of extensibility decrease.
what is tenodesis?
A person who is quadriplegic and has no voluntary ability to open and close the fingers can use this principle to grasp and release light objects. By supinating the forearm, the weight of the hand and gravity causes the wrist to fall into hyperextension. This closes the fingers, creating a slight grasp. Pronating the forearm causes the wrist to fall into flexion, thus opening the fingers and releasing an object.
what is isometric muscle contraction
When a mm contract producing force without changing the force of the muscle
An isometric contraction occurs when a muscle contracts, producing force without changing the length of a muscle
what is isotonic muscle contraction
Contractions that involve shortening of the muscle
what is a concentric contraction
A concentric contraction occurs when there is joint movement, the muscles shorten, and the muscle attachments (origin and insertion ) move toward each other. It is sometimes referred to as a shortening contraction.
what is an eccentric contraction
An eccentric contraction occurs when there is joint motion but the muscle appears to lengthen; that is, the muscle attachments separate
what is acceleration and deceleration
the speed inwhich the muscle moves
what is force of gravity
this is when you allow gravity to help or resist muscle movement
what is gravity-elminated with mm contraction
this is where a pully type device or gravity-eliminated position like side-lying with the arm supported, to aid in movement when the pt is unable to make the movement themselves.
roles of muscles: agonist
muscle or muscle group that causes the motion
also called the prime mover
roles of muscles: antagonist
potenially oppeses the prime mover
In the case of elbow flexion, the antagonist is the triceps muscle.
role of muscles: co-contraction
When the antagonist contracts at the same time as the agonist
role of muscles: stabilizer
A stabilizer is a muscle or muscle group that supports, or makes firm, a part allowing the agonist to work more efficiently.
For example, when you do a push-up, the agonists are the elbow extensor muscles. The abdominal muscles (trunk flexor muscles) act as stabilizers to keep the trunk straight, whereas the arms move the trunk up and down.
also called a fixator.
role of muscles: neutralizer
contracts to prevent the unwanted motion
roles of mucles: synergist
A synergist is a nonspecific term describing a muscle that works with one or more other muscles to enhance a particular motion.
what is (line) angle of pull
the path which the muscles traves, it’s insertion and origin, joints is crosses, etc.
Kinetic chains: open kinetic chain
distal limb segment is fixed while proximal segment moves; static lunges, push-ups, squats, pull ups
If you were to remain seated and extend your knee, your hip and ankle joint would not move. This is an open kinetic chain activity.
Kinetic chains: close kinetic chain
distal limb segment is not fixed; free to move
i.e., biceps curls, knee extensions, walking lungesdistal limb segment is fixed while proximal segment moves; static lunges, push-ups, squats, pull ups
Usually when a muscle contracts, the distal attachment moves toward the proximal attachment.
What is another name to describe the distal attachment?
Insertion
Usually when a muscle contracts, the distal attachment moves toward the proximal attachment.
What is another name for the proximal attachment?
origin
What is the term that describes a muscle contraction in which the proximal end moves toward the distal end?
Reversal of muscle action
The flexor carpi radialis performs wrist flexion and radial deviation. The flexor carpi ulnaris performs wrist flexion and ulnar deviation.
In what wrist action do the two muscles act as agonists?
Agonists in wrist flexion
The flexor carpi radialis performs wrist flexion and radial deviation. The flexor carpi ulnaris performs wrist flexion and ulnar deviation.
In what wrist action do they act as antagonists?
Antagonists in ulnar/radial deviation
The following chart identifies the hip motions of three muscles. Hip extension is the desired motion.
Gluteus Maximus: Extension & Lateral Rotation
Hamstrings: Extension
Gluteus minimus: Medial Rotation
Which of these muscles are acting as agonists in hip extension?
Gluteus maximus and hamstrings
The following chart identifies the hip motions of three muscles. Hip extension is the desired motion.
Gluteus Maximus: Extension & Lateral Rotation
Hamstrings: Extension
Gluteus minimus: Medial Rotation
What motion must be neutralized so the agonists can do only hip extension?
Hip lateral rotation
The following chart identifies the hip motions of three muscles. Hip extension is the desired motion.
Gluteus Maximus: Extension & Lateral Rotation
Hamstrings: Extension
Gluteus minimus: Medial Rotation
What muscle must act as a neutralizer to rule out the undesired motion?
Gluteus minimus
What is the term for the situation in which a muscle contracts until it can contract no farther, even though more joint range of motion is possible?
Active insufficiency
Is walking downhill a concentric or an eccentric contraction of your quadriceps muscle?
Eccentric
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What is the joint motion at the shoulder?
Shoulder abduction
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
Is an isometric, concentric, or eccentric muscle contraction occurring at the shoulder?
Concentric
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What muscle group is contracting at the shoulder?
Shoulder abductors
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What type of muscle contraction is occurring at the elbow?
Isometric
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What muscle group is contracting at the elbow?
Elbow extensors
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What is the joint motion at the shoulder?
Shoulder flexion
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
Is an isometric, concentric, or eccentric muscle contraction occurring at the shoulder?
Concentric
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What muscle group is contracting at the shoulder?
Shoulder flexors during first 90 degrees
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What type of muscle contraction is occurring at the elbow?
Eccentric
Sitting with a weight in your hand, forearm pronated, elbow extended, and shoulder medially rotated, slowly move your hand out to the side and raise it.
What muscle group is contracting at the elbow?
Shoulder extensors during second 90 degrees
Identify the following in terms of open- or closed-kinetic chain activities:
Wheelchair push-ups
Wheelchair push-ups: closed-chain activity
Identify the following in terms of open- or closed-kinetic chain activities:
Exercises with weight cuffs
Exercises with weight cuffs: open-chain activity
Identify the following in terms of open- or closed-kinetic chain activities:
Overhead wall pulleys
Overhead wall pulleys: open-chain activity
What position would a person have to be in to perform shoulder abduction and adduction in a gravity-eliminated position?
Supine (or prone) lying
For a muscle to have an effective angle of pull to be a shoulder flexor and not a shoulder abductor, it would have to span the shoulder on what surface?
Anterior surface
The rectus femoris flexes the hip and extends the knee. The vastus medialis extends only the knee. In what position must the hip and knee be placed to be able to stretch only the vastus medialis?
The hip must be flexed to place the rectus femoris on slack, and the knee is flexed.
If you wanted a muscle to lift a very strong load, what muscle fiber arrangement would you want?
Oblique
If you wanted a muscle to contract through a very great range, what muscle fiber arrangement would you want?
Parallel
In terms of muscle tissue characteristics:
What can a muscle do that a rubber band cannot?
Contract
In terms of muscle tissue characteristics:
What characteristic does a rubber band have that chewing gum does not?
Elasticity
Please perform an analysis of what is happening to the length of the rectus femoris muscle at both the hip and the knee when an individual moves from a seated position to a standing position.
The rectus femoris is lengthening over the anterior aspect of the hip and contracting (shortening) over the anterior aspect of the knee.
