Exam 2 Flashcards
Definition of osteokinematics vs. arthrokinematics
Osteokinematics - focuses on actions with respect to planes and axes (eg the movement of bones along joint axes)
Arthrokinematics - focuses on the small, unseen actions that occur with a joint between the surfaces
The types of arthrokinematics movements: glide, spin and roll. Be able to understand and
explain the convex/concave rule
roll= One surface rolls against another like a tire going down a road.
Glide: One surface slides against another like a tire skidding on a slippery road
Spin: One surace rotates against another like a car tire spinning out when it’s in the mud
convex/concave rule= when convex surface moves over the concave surface, glide and roll are in the opposite directions . When the concave surface moves around the convex surface, glide and roll are in the same direction
Open chain vs. closed chain movement
open chain= freely moving (curls)
closed chain= pushing against a fixed surface (squat, feet statiionary)
Open packed and close packed position; know what these mean and be able to give examples at
the knee and shoulder
Close-packed position: most stable, most congruent (greatest surface contact) and joint capsule is taut
Open-packed position: the least stable, loosest connective tissue, least congruent position of the joint
forces that act on joint
Traction (also tension or distraction) – joint surfaces are pulled apart
Compression (also approximation) – external force pushes joint surfaces together
Shear – external force glides the bone surfaces relative to one another
Combining forces:
Bending force is compression on one side with traction on the other side
Torsional force is a twisting/rotational force
Understand how muscle fibers generally function (eg they pull/get shorter actively, do not
push/get longer actively
muscle cell= muscle fiber
muscle cells function is to contract,
muscle cells cant push only pull
mobility= contraction of muscle cells is greater than outside force
stability= contraction of muscle cells equal to outside force
Understand the sliding filament mechanism including the following vocabulary
a. Actin
b. Myosin
c. M-line
d. Z-disc
e. H-zone
f. I-band
g. Sarcomere
h. Epimysium
i. Perimysium
j. Endomysium
k. Myofibril
l. Myofilament
m. Titan
sliding filament mechanism= Myosin heads at both ends of the thick filament attach to actin,
Myosin heads change shape which pulls the thin filaments toward the M-line,
Myofibril gets shorter from the telescoping action
actin= thin filaments
myosin= thick filaments
M-line (middle line) – center of the myosin (thick) filament
Z-disc (zigzag) – the end structures of the sarcomere –
H-zone= center where there is no overlap between thick and thin filaments
I-band= part of sarcomere that contains thin filaments
Sarcomere= the adjacent groups of myofilaments
Epimysium= covers the whole muscle belly
Perimysium separates the belly into fascicles (motor units)
Endomysium wraps each individual muscle fiber (muscle cell, also called extrafusal fiber
Myofibrils: The cylindrical, contractile organelles that make up each muscle fiber (cell)
Myofilaments: the protein structures that make up myofibrils
Describe the structure of muscles from the cellular level to the muscle belly
Many sarcomeres laid end to end form a myofibril
8-10 myofibrils bundled together create a muscle fiber (AKA muscle cell)
Muscle fiber/cell will have many nuclei and contain mitochondria
Myofibrils will be wrapped in sarcoplasmic reticulum with transverse tubules to be sure that calcium ions penetrate all parts of the cell
Bundles of myofibrils are wrapped in a sarcolemma (a membrane) which is fluid filled
Sarcolemma is then wrapped in endomysium
10-20 muscle fibers make a fascicle (a contractile unit), wrapped in perimysium and innervated with a nerve ending
A few hundred fascicles are wrapped together to create the muscle belly which is wrapped in epimysium
Know the functions and properties of muscle
function create movement, stabilize posture, assist with fluid circulation, perform thermogenesis
properties-
Excitability – the capacity to respond to stimuli
Contractility – The ability to develop tension when stimulated
Extensibility – the capacity to stretch without being damaged
Elasticity – tendency to return to its original length after being stretched
Muscle shapes and arrangements – pennate vs. parallel and how that impacts their function
Parallel muscle requires long fibers
and usually two short tendons, one
at each end, more ROM
Pennate belly calls for a larger
number of muscle fibers of shorter
length, with one or two long
tendons running the length of the
muscle, stronger
Motor neuron organization with respect to muscle fibers
amount of motor units firing determines the amount of contractile tension (force)
not all units fire simultaneously, there’s a sequential pattern of motor units turning off and on.
Types of muscle fibers (slow and fast twitch)
Slow fibers (Type 1) –
endurance; stay on
longer, fatigue slowly
Fast fibers (Type IIA) –
Larger, produce
faster contractions,
fatigue quickly,
recover slowly
Fast fibers (Type IIB) –
biggest and most
powerful, fatigue very
fast. Used for power.
Muscle tone – hyper and hypotonia
High tone is called “hypertonia”
Low tone is called “hypotonia
Types of muscle contractions – you should be very familiar with this by now!
Isotonic
Concentric= greater than the force of gravity (against gravity)
eccentric= less than force of gravity (moving with gravity)
Be very familiar with the roles of muscles from lecture 3 on muscles (agonist etc). For the major
muscles that we have discussed in class, be able to name a movement where that muscle is
agonist or antagonis
agonist= prime mover
antagonist= opposes action
elbow flexion: biceps is agonist, triceps is antagonist
Elbow extension: triceps is agonist, biceps is antagonist
synergist= any muscle-assisting the agonist (knee flexion, hamstrings are the agonist, gastrocnemius would be the synergist)
Understand how fiber direction impacts muscle function
Muscle fiber direction is rarely exactly in the direction that you are trying to move
For example, the hamstrings have an oblique angle. Muscles only shorten exactly in the direction of their fibers
Other muscles act to balance out the pull in a slightly different direction that is caused by the orientation of the agonist.
In the case of the hamstrings, they cross both the hip and knee joint. That means they can both flex the knee and extend the hip. If we are trying to only flex the knee, the hip flexors contract to neutralize the hip extension part of the movement, leaving only knee flexion
Postural vs. phasic muscles and how they are likely to relate to slow vs fast twitch
Postural muscles are designed to work for long periods of time in a semi-contracted state to keep you upright. Good endurance.
Phasic muscles perform movement and can act quickly. They fatigue quickly
Examples of muscle imbalance – long and weak vs. tight and strong
A muscle imbalance will often occur when a postural muscle becomes short and tight while the phasic muscle that is its antagonist because long and weak.
Basic structure of the nervous system
Central Nervous System (CNS)= Brain and spinal cord.
Peripheral Nervous System (PNS)= Has the autonomic nervous system and Somatic nervous system. Autonomic (involuntary) has the sympathetic and parasympathetic. Somatic is voluntary
Nerve cell structure
A cell of the nervous system is called a neuron and has three basic parts
Cell body which contains the nucleus
Dendrites are branches that extend off the cell body and make connections (transmit toward the cell body)
Axon is a long tail that extends away from the cell body. An axon can be very long! (transmit away from the cell body)
Afferent vs. efferent
afferent= carry information to CNS (sensory neurons)
efferent= carry information away from CNS (motor neurons)
Parts of the brain; central vs. peripheral nervous system
PNS=
CNS=cerebrum
Sympathetic vs. parasympathetic
Sympathetic – excitatory, fight or flight, speeds up processes
Parasympathetic – relaxing, rest and digest, slows down process
Know vocabulary from these lectures such as synapse, epineurium etc
synapse= A junction between any two neurons or a neuron and an organ (like muscle or gland
Nerves have fascia-coating layers just like muscles
Endoneurium coats each individual axon
Perineurium coats a group of axons
Epineurium sheaths the entire nerve
Cranial nerves 1-12; names and their roles (this would show up in matching or multiple choice
Oh, Oh, Oh, To Touch And Feel Very Good Velvet, Such A Heaven
CN I – Olfactory – sense of smell
CN II – Optic – sense of sight
CN III – Oculomotor – eye movements
CN IV – Trochlear – eye movements
CN V – Trigeminal – face sensation and jaw movement
CN VI – Abducens – eye movements
CN VII – Facial – face movements and sensation
CN VIII – Vestibulocochlear – sense of hearing and balance
CN IX – Glossopharyngeal – taste sensation and tongue movement
CN X – Vagus – controls organ function such as heart/digestion
CN XI – Accessory – upper traps and SCM muscles
CN XII – Hypoglossal – swallowing muscles
Definition of proprioception
Defined as the nervous system’s ability to perceive where the body is
in space and in relation to itself
Basic mechanism of Golgi tendon organ and muscle spindle
muscle spindle= The job of muscle spindle cells is to gauge the amount of stretch on a muscle cell,
The purpose of the muscle spindle cells is to protect the muscle from tearing if it
gets stretched too far
golgi tendon organ= the job of the GTO is to protect the tendon by detecting and
responding to changes in muscle tension, opposite effect of muscle spindle
Reflexes: stretch reflex, reciprocal inhibition and how they work
Reciprocal inhibition means that there is
a reflex arc that causes the antagonist
to relax when the agonist activates
Stretch reflex = an example of a reflex arc. The route starts at the muscle spindle
organ, sends a signal to the spinal cord which quickly sends back a motor
message for the muscle to contract. There is no conscious control over this
Newton’s laws of motion
1= (law of inertia )An object at rest
tends to stay at rest,
an object at motion
tends to stay in
motion”
2= (law of acceleration) F=MA
3= (law of action-reaction) For every action
there is an equal and
opposite reaction
Classes of levers
first class lever= Axis is in the middle
Effort arm is longer than resistance arm
Specialty is force amplification
Expense is range of motion (ex: crowbar, neck flexion/extension
second class lever= The load (resistance) is placed between the axis
and the effort (axis is at one end)
Specialty is force production
Expense is a
range of motion and speed (ex: wheelbarrow, raising up your toes)
third class leverl= The effort is placed closer to the axis than the
resistance
Specialty is speed and Range of motion
Expense is force production (example: shovel, limbs)
Forces
i. Linear
ii. Concurrent
iii. Resultant
Linear force: Forces all occur along the same line of pull
Concurrent forces: When two or more forces connect at a common
point but pull together in one direction
► Rectus femoris and vastus intermedius
Resultant forces: Net result of two or more different forces
► Anterior fibers and posterior fibers of the gluteus medius cancel out
anterior and posterior directions of movement; resulting force is straight
abduction in the frontal plane
Vector
Moment arm
Torque
Vector – a force with direction and magnitude
Torque - a twisting force. The force still has a linear direction, but
causes a rotational displacement
moment arm= think about how holding a barbell up with weight on one side. Its easier to hold it up closer to the weight side rather than the opposite.
Stability and its components, principles of stability
stability= ability to be firmly supported
Components of stability
Center of gravity – an imaginary balancing point where the weight of an object is
concentrated
Base of support – the part of the body in contact with the supportive surface (can include
an assistive device)
Line of gravity – an imaginary plumb line that runs straight through your head, torse and
center of gravity to the ground
Be able to draw the basic form of a joint with motion (bones, axis, line of pull, moment arm
