Kinesiology-massage therapy school
which type of lever is most efficient
2 class levers
which type of lever has a mechanical disadvantage?
3rd class
how much does the pelvis move laterally during gait?
5cm
which fibers are the fastest and which are the slowest?
A - fastest C- slowest
sensory impulse from viscera to the brain are examples of which kind of fibers?
B fibers
what is a neurological gait described as?
CNS disorders
between Isometric, Isotonic concentric and essentric, which one produces the most force/tension
Essentric
True or False: adapted for maintaining posture and for aerobic, endurance activities like marathon running
True
what is the secondary agonist?
the muscle that helps produce desired action
Define Biomechanics
the study of mechanical laws and their applications to the living organism, especially the human body and its locomotor system
Kinetics
the study of the forces that produce, inhibit, or modify the motions of the body - Newtons laws 1 and 3 are very applicable to the study of kinetics
what is a fixator muscle?
this muscle will stabilize origin of prime mover so that the prime mover can be more efficient. - stabilizes a bone that is an attachment site for the prime mover
What is the "All or None Law?" (muscle stimulation)
when muscles are stimulated/excited at the neuromuscular junction by nerve, muscle fibers contract; if stimulation is inadequate (does not reach the threshold), muscles will not contract at all increased intensity of impulse to muscle will not change the muscle fiber response
What are the 3 planes of Reference for movements?
1. Frontal/Coronal - divides the body in front (anterior) and back (posterior) halves 2. Sagittal - divides the body in the right and left halves 3. Transverse or horizontal - divides the body in upper (cranial) and lower (caudal) halves
during midstance how many degrees of flexion does the knee have?
15
what is the conjoint synergist
2 muscles that work together to produce a movement which they could not produce indvidually
what is the average amount of pelvic rotation
3-5 degrees
which type of lever is very inefficient
3rd class
which type of lever do we have most of in our body?
3rd class levers
swing phase accounts for approximately ___% of the gait cycle
40%
stance phase accounts for ___% of the gait cycle?
60%
what % is maximal tension developed at?
80-120% of resting length
Out of the 3 Nerve Axon Diameters fibers(A, B and C) which has the largest diameter?
A Fibers (5-20um)
out of the 3 fibers, which are myelinated?
A and B fibers
Impulses from axons of motor neurons to skeletal muscles are examples of which type of Fibers?
A fibers
sensory impulses for touch, pain, temperatures of skin are examples of which type of Fibers?
C fibers
True or false: Isometric contraction produces less force/tension compared to a concentric contraction
False! it produces more. it does not use as much energy since muscle length doesn't change
Do Penniform fiber arrangements have less ROM or more?
Less
true or false: spurt muscles have their proximal attachments further from the joint and their distal attachments to the joint
Trueeee
what are the stages of stance phase?
a - heel strike to foot flat b- foot flat to mid stance c- midstance to heel off d- heel off to toe off (push off period)
what is the neutralizing/counteracting synergist?
a muscle that crosses more than 1 joint may produce the desired action at one joint but produce an undesirable action at the 2nd joint
what are the stages of swing phase?
a- toe off to mid swing (period of acceleration) b- midswing to heel strike (deceleration)
describe contractility
ability of muscle tissue to produce tension between its ends, leading to forceful contraction when stimulated by AP
Elasticity
ability of muscle tissue to return to its original length and shape after a contraction or extension (stretch) - ability to recoil
Distensibility/Extensibility
ability of muscle to stretch without being damaged, the stretch may be induced by gravity or by our own body
describe Irritability/excitability of a muscle.
ability of muscles to be stimulated by a stimulus (action potential) leading to muscle contraction
where do spurt muscles direct their forces?
across the bone and not along it
where do shunt muscles direct their forces
along the bone - pulls bones together
what is Newtons (1st law) Law of Inertia?
an object at rest tends to stay at rest, an object in motion tends to stay in motion, with the same speed and in the same direction, unless acted upon by an unbalanced force -inertia = the resistance an object produces, to a change in its state of motion
9 month pregnant woman, anterior or posterior center of gravity?
anterior
the ankle joint - the line of gravity falls ____________ to the axis of the ankle joint.
anterior
the knee joint - the line of gravity falls ______________ to the axis of the knee - posterior or anterior
anterior
is the plum line anterior or posterior to the knee?
anterior to axis of the knee (posterior to patella)
how much does the pelvis drop during gait?
apporximately 4-5 degrees
what does the cerebellum help to maintain?
balance
what is the stance phase?
begins from the time of initial contact until the toes leave the floor at toe-off
what is swing phase ?
begins when the great toe leaves the floor and ends when the heel makes floor contact
give an example multipenniform
deltoid muscles
fusiform muscle fibers example
digastric and biceps brachii muscles
when does the lowest point occur at?
double support (both flat feet)
are Pecs an example of fast twitch or slow twitch fibers
fast twitch
give an example of a unipennate fiber arrangement
flexor and extensor digitorum longus muscle
what is Newtons (3rd law) reaction
for every action, there is an equal and opposite reaction - if object A exerts a force on object B, then object B also exerts an equal an opposite force on object A
are second class levers designed for force? or speed?
force
what are Slow twitch fibers designed for?
generate force throughout a long time period - the force generated is much less, however can be sustained for a prolonged period of time
in Antalgic Gait disorders, what is usually absent?
heel strike.
will a large breasted woman or nursing mother have a higher or lower center of gravity?
higher
which stage does the highest point of gait occur in
highest point occurs at mid-stance
Describe Lengthened Active Insufficiency
inability of a 2 joint muscle to generate an effective force when placed in a fully lengthened position
Describe Shortened Active Insufficiency?
inability of a 2 joint muscle to generate an effective force when placed in a fully shortened position
Describe muscle irritability
intensity required to stimulate a particular muscle fiber - is dependant on a muscle fibers irritability
which produces the least amount of force/tension?
isotonic concentric
in females is center of gravity usually higher or lower?
its typically lower
when muscle fibers are highly irritable, is more or less intensity required?
less is required
would a body builder who trains to power lift from his legs only, have a higher or lower center of gravity?
lower
are spurt muscles movers or stabilizers?
movers
Tone
muscle at rest exhibits a small amount of tautness or tension; is established by CNS
what is a STABILIZING synergist?
muscle group that stabilizes a proximal joint so that the more distal joint may produce the desired action
what is the prime mover
muscle that contracts to cause desired movement ; muscle most responsible for the completion of desired action
what is a paralytic Gait described as?
muscular weakness disorders
what is an Antalgic Gait described as?
pain disorders
Triangular muscle fiber example
pec major muscle
whats mid-stance?
period between foot flat and toe-off
does the line of gravity fall posterior or anterior to the axis of a joint?
posterior to the axis of a joint - therefore our anterior muscles, ligaments and joints capsules work to maintain neutral position
where are the attachment points for shunt muscles
proximal attachments closer to the joint and their distal attachments further from the joint
give an example of bipennate
rectus femoris muscle
what is a structural gait described as?
reduced ROM disorders
which length of a muscle fiber is the length at which it can generate the maximum force?
resting length
what tract does the information travel along?
reticulospinal tract to the cervical or lumbosacral spine
Rhomboidal muscle fibers?
rhomboid major/minor, pronator quadratus muscles
give an example of Straplike muscle fibers
sartorious, stylohyoid muscles
give an example of a 1st class lever
scissors, pliers.
Define Kinesiology
The scientific study of muscular activity and the anatomy, physiology and mechanics of the movement of body parts
what are 3rd class levers designed for?
speed and ROM
are shunt muscles stabilizers or movers?
stabilizers
what is Newtons (2nd law) Law of Acceleration
the acceleration of an object, as a produced by a force, is directly proportional to the magnitude of the force and inversely proportional to the mass of the object - explains how the velocity of an object changes when its subjected to an external force
Define Dynamics
the branch of biomechanics that studies movement and its velocity, acceleration and associated forces
Describe an Isometric muscle contraction
the involved muscle neither lengthens or shortens
what controls the cervical and lumbar pattern generators?
the midbrain
what is "festinating gait" described as?
the trunk is flexed forward, and the person may have difficulties with stops and turns appearing to chase after their Center of Gravity
what are Fast Twitch fibers designed for?
to produce powerful actions for short durations - the force generated is large
True or False: the speed of contraction is inversely proportional to the load
true
give an example of 2nd class levers
wheelbarrow, nut cracker