KINE 3050: Muscle

muscle

What is the source of the force needed for movement?

magnitude, velocity, direction

What do we need to consider for forces?

force, cross-sectional area, sarcomeres, arranged, penetration angle, advantage

___ is dependent on:

*Muscle ___-__ ___ (CSA)

*Number of ___ and how they're ___

*Muscle fiber ___ __

*Mechanical ___ or disadvantage

rate, duration, development, fiber

The ___ and ___ of force ___ is dependent on ___ type

form, function

Muscle architecture:

*___ dictates ___

sarcomeres

contractile units within myofibrils, the smallest contractile unit of a muscle

myosin, thick

A protein present in muscle fibers that aids in contraction and makes up the majority of muscle fiber

*___ filament

actin

thin filament

myosin, actin, heads, binding site

In order for ___ to pull ___ over, the myosin ___ must attach to a specific ___ ___ on actin filament

actin-myosin cross bridge

The bond formed when a myosin head binds to an actin filament

force, directly, cross bridges

Overall __ production is ___ related to number of ___ ___ that are formed

Goldilocks, normal, highest, production

____ zone: has ___ (resting) length, and ___ force ___ capability

short, low, full, shortened, itself, difficult, attach

Too ___, ___ force production:

*Sarcomere is near ___ contractile length

*Lots of overlap between actin & myosin, but it's ___ too much that actin begins to overlap ___ in some areas

*Makes it more ___ for myosin heads to ___ in cross-bridge

normal resting length

length of muscle when it is not shortened or lengthened

nearly, stretch, beyond, heads, binding, cross-bridge

___ optimal, beginning to ___

*Nearly optimal position, but just ___ normal resting length

*Some myosin ___ that can't quite reach the ___ site, and can't form a ____

maximal, low/no, stretched, much, few, reach

___ sarcomere length, ___/___ force production

*Sarcomere is maximally ___ out of length

*Far too ___ and very ___ myosin heads are able to ___ binding site

cross-bridge, length, sarcomere, overlap

The number of ____ that can form is related to the ___ of the ___ and amount of ___ between the myosin & actin

normal/resting length

When does optimal force production occur?

length-tension relationship

The resting length of a muscle and the tension the muscle can produce at this resting length.

passive, stretching, connective, force, lengthening, stretching

Sarcomeres have ___ resistance to ___ from ___ tissue that don't produce ___ themselves but resist ___ or ___

90 degrees

Which position is an exercise the most difficult: 90 or 160 degrees?

90, torque, moment arm, external, third, disadvantage

It's hardest to move at ___ degrees due to torque, or, more specifically, the ___ ___, particularly the ___ component

*__ class lever, mechanical ____

sticking point

The most strenuous movement of a repetition; typically occurs soon after the transition from the eccentric phase to the concentric phase.

cams, mechanical advantage, single

*___ are used in weight training machines to alter ___ ___

*Primarily designed for ___ joint movements

mechanical advantage, multiple, chains, rubber bands

You can change ___ __ in free weight ___ joint exercises using ___ & ___ __

high, low, large

Sarcomeres in SERIES will have ___ velocity and __ forces

*Have ___ excursion

low, high, small

Sarcomeres in PARALLEL will have ___ velocity and __ forces

*Have ___ excursion

full length, small

Some muscle fibers run the __ __ of the muscle while others only cover a ___ distance of overall muscle length

grow, diameter, length, adulthood

Muscle fibers can ___ in ___ & in ___ through ___

series, longer, longitudinal, end, end

Sarcomeres in ___ are usually found in ___ muscle fibers that run along the ___ axis of muscle and will attach __ to ___

parallel, pennate, shorter, tendons

Sarcomeres in ___ are predominately found in ___ muscle fiber and will be much ___ and will attach directly to ___

pennation, cross sectional area

Muscle fiber ___ also impacts __ __ ___

anatomical, diameter, thickest

___ CSA ___ of the __ part of the muscle

physiological, perpendicularly, arrangement

___ CSA is measured ___ to muscle fiber ___

greater, pennate

PCSA will be ___ than ACSA when ___ fibers are present

parallel/pennate

Which produces a greater force production?

*Series or parallel/pennate

series

Which produces a greater movement velocity?

*Series or parallel/pennate

antagonistic muscle pairs

how all muscles are arranged

contraction & relaxation

What do antagonistic muscle pairs cause?

stretched, antagonist

Each muscle can only be ___ by its ____ muscle

dynamometers & force plates/gauges

What do you use to measure force/torque capability

ultrasound

What do you use to measure muscle architecture?

electromyography

What do you use to measure muscle activation?

isokinetic dynamometer

How can we measure SINGLE joint moment?

isokinetic

a muscle contraction with a constant speed of contraction

closed kinetic-chain exercise

exercise incorporating several muscle groups through the use of several joints with the end segment fixed

force plate, closed, isometric

How can we measure MULTIPLE joint moment?

*Only works for ___ kinetic-chain exercises or ___ exercises

pennation angle, fibers/muscle length, cross sectional area

What can you look at using ultrasound for muscle architectures (3)

pennation angle

angle of orientation between muscle fibers and tendon

electrodes, on, into, electromyography, EMGs

*Muscle activation can be measured by putting ___ __ or ___ a muscle

*Called ___ and resulting signals are called ___

EMG, summation, discharges, motor units, electrode

The __ signal is the ___ of the ___ of all __ ___ within the pick-up range of the ___

threshold, depolarization, repolarization, hyperpolarization

What are the 4 steps of electric muscle potentials?

Na+, in

In depolarization, ___ flows __

K+, out

In repolarization, ___ flows __

waves, depolarization, repolarization, electrodes, short

"___" of ___ & ___ are detected by recording ____, but only for a ___ distance

-90mV to -70mV

What is the value/range for resting membrane potential

inside, 30-40mV, recorded, multiple, motor unit simultaneously

With sufficient stimulation potential ___ cell rises to __-_ __

*Change in potential can be ___

*Action potentials from ___ fibers in a __ __ can be ___ recorded

Schematic Representation

Measure of changes in electrical potential across muscle fiber

motor unit action potential

*Signal from depolarization of motor unit

the summed electrical activity of all muscle fibers activated within the motor unit

two

How many electrodes do you need at minimum for an EMG?

force, nonlinear, more, more, much

EMG is related to muscle ___

*Relationship is ___: when you have ___ EMG, you have more ___, but don't know by how ___

electromyography, muscle, activity, on, off, fatigued

___ Uses:

*Provides an indication of how much a __ is being used during a certain ___

*Is muscle __ or __

*Is a muscle ___

electromyography, clinical, neuromuscular, neurological

___ __ Uses:

*Assessment of ___ & ___ disorders

surface, most, small, muscle belly, skin

___ Electrode

*___ commonly use

*___ recording surface

*Placed over ___ ___

*Only can measure single that reaches the ___

hair, oil, dirt, skin

What do you need to remove (4) to have adequate skin preparation for surface electrodes?

indwelling/needle, hypodermic needle, deep, motor units, many, activity

___/___ Electrodes:

*Insert directly into muscle via ___ __

*Used for ___ muscle

*Used to identify different ___ __ recruited or how ___ motor units recruited during an ___

direct, muscle, electrode

What is the relationship between electrode signal & force

*ONLY within the SAME ___ w/ the SAME __

primary, movement, no direct, concentric, eccentric, force

EMG Use (part 1):

*The ___ muscle involved w/ a particular ___

*___ indication of muscle force

*___ or ___ contractions

*Related to muscle ___

electromyography, antagonist

____ helps to measure ___ muscle activity

Ex: Hamstring activity at terminal phase of knee extension

fatigue, recruitment, frequency, signals, type, conduction velocity

EMG Use (part 3):

*Assessment of muscle ___ & ___ of different motor units/fiber types

*Analyzing the ___ of the EMG __

*Related to __ of motor unit activated & __ __

resilient, stretched, shortened, high, damage

Muscle is a ___ tissue

*__ or __ at fairly __ speeds without major __

irritability, contractibility, extensibility, elasticity

What are the 4 properties of muscle?

irritability, stimuli, electrical, contraction

____:

*Ability to receiver & respond to ___ via generation of an __ pulse that causes muscle cells ___

contractibility

ability to shorten

extensibility

ability to be stretched or extended

elasticity, recoil, resting

____:

*Ability of a muscle fiber to ___ and resume its __ length

performance, loads, velocities

The four properties of muscle determine the ___ of muscle tissue under various __ & ___

muscle, movement, postures/positions, stabilize, heat

___ functions:

*Produce ___

*Maintain ___/___

*___ joints

*Generate body ___

agonist

Muscle or group of muscles that causes the motion

assist, prime, less

___: assist the movement of a __ mover but is __ effective

antagonist

performs the OPPOSITE motion of the prime mover

stabilize, hold, immobile

___: Muscle may contract to __ a body part ___ while another part is moving

neutralize, unwanted, specific

___: prevents __ motions a muscle can perform so a __ motion can occur

agonist, assist, antagonist, stabilize, neutralize

What are the 5 roles a muscle can have for a given movement?

continued, concentrically, distal, contract, proximal

____ Action:

*Muscle FIRST ___ contracts to perform the motion at the most ___ joint is crosses

*Then continue to ___/shorten and perform motions at more ___ joints through continued action

reverse, proximal, distal

___ function

In muscle CONCENTRICALLY contraction: ___ attachment to __ attachment

towards

In a REVERSE function CONCENTRIC contraction, proximal lever moves ___ (the or from) the distal lever

reverse, concentric, heavy work

The ___ function of __ contraction is associated w/ ___ ___

arrangement, axis, generation

___ of muscle fibers within a muscle relative to the __ of force ___

consistent, diameter, sizes, generation

*Relatively ___ fiber __ between muscles of different __

*Differences can affect force ___

architectural, variability, function

§____ differences between muscles have much:

§More ___

§Impact ___

parallel/longitudinal, fusiform, pennate

What are the 3 classes muscles fibers can have

*Abdominals

*Biceps brachii

*Digital extensor, rectus femoris (can be uni or bi)

slow-twitch oxidative, fast-twitch oxidative, fast-twitch glycolytic

What are the 3 types of muscle fibers?

*Type I, IIA, IIX

slow, oxidative, slow, small, long, slow, resistant, aerobic/oxidative, high, red

___ Twitch __ Fibers (Type I)

*___ myosin ATPase activity

*___ size/diameter

*___ contraction duration

*___ SERCA pump activity

*Fatigue __

*Uses ___/___ energy

*__ capillary density/mitochondria

*Color: ___ (has myoglobin)

fast, oxidative, fast, medium, short, fast, resistant, aerobic, anaerobic, medium, red

___ Twitch __ Fibers (Type IIA)

*___ myosin ATPase activity

*___ size/diameter

*___ contraction duration

*___ SERCA pump activity

*Fatigue __

*Uses BOTH ___ & ___

*__ capillary density/mitochondria

*Color: ___ (has myoglobin)

fast, glycolytic, fast, large, short, fast, easily, anaerobic/glycolytic, low, white

___ Twitch __ Fibers (Type IIX)

*___ myosin ATPase activity

*___ size/diameter

*___ contraction duration

*___ SERCA pump activity

*Fatigue __

*Uses ___/__ energy

*__ capillary density/mitochondria

*Color: ___

slow-twitch oxidative

Which fiber is the only one with SLOW Myosin ATPase activity?

slow-twitch oxidative

Which fiber is the only one with LONG contraction duration?

slow-twitch oxidative

Which fiber is the only one with SLOW SERCA pump activity?

fast-twitch glycolytic

Which fiber is the only one that is EASILY fatigued?