Exam 2

Question 1

Definition of osteokinematics vs. arthrokinematics

Answer 1

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

Question 2

The types of arthrokinematics movements: glide, spin and roll. Be able to understand and
explain the convex/concave rule

Answer 2

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

Question 3

Open chain vs. closed chain movement

Answer 3

open chain= freely moving (curls)
closed chain= pushing against a fixed surface (squat, feet statiionary)

Question 4

Open packed and close packed position; know what these mean and be able to give examples at
the knee and shoulder

Answer 4

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

Question 5

forces that act on joint

Answer 5

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

Question 6

Understand how muscle fibers generally function (eg they pull/get shorter actively, do not
push/get longer actively

Answer 6

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

Question 7

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

Answer 7

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

Question 8

Describe the structure of muscles from the cellular level to the muscle belly

Answer 8

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

Question 9

Know the functions and properties of muscle

Answer 9

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

Question 10

Muscle shapes and arrangements – pennate vs. parallel and how that impacts their function

Answer 10

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

Question 11

Motor neuron organization with respect to muscle fibers

Answer 11

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.

Question 12

Types of muscle fibers (slow and fast twitch)

Answer 12

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.

Question 13

Muscle tone – hyper and hypotonia

Answer 13

High tone is called “hypertonia”
Low tone is called “hypotonia

Question 14

Types of muscle contractions – you should be very familiar with this by now!

Answer 14

Isotonic
Concentric= greater than the force of gravity (against gravity)
eccentric= less than force of gravity (moving with gravity)

Question 15

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

Answer 15

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)

Question 16

Understand how fiber direction impacts muscle function

Answer 16

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

Question 17

Postural vs. phasic muscles and how they are likely to relate to slow vs fast twitch

Answer 17

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

Question 18

Examples of muscle imbalance – long and weak vs. tight and strong

Answer 18

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.

Question 19

Basic structure of the nervous system

Answer 19

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

Question 20

Nerve cell structure

Answer 20

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)

Question 21

Afferent vs. efferent

Answer 21

afferent= carry information to CNS (sensory neurons)
efferent= carry information away from CNS (motor neurons)

Question 22

Parts of the brain; central vs. peripheral nervous system

Answer 22

PNS=
CNS=cerebrum

Question 23

Sympathetic vs. parasympathetic

Answer 23

Sympathetic – excitatory, fight or flight, speeds up processes
Parasympathetic – relaxing, rest and digest, slows down process

Question 24

Know vocabulary from these lectures such as synapse, epineurium etc

Answer 24

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

Question 25

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

Answer 25

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

Question 26

Definition of proprioception

Answer 26

Defined as the nervous system’s ability to perceive where the body is
in space and in relation to itself

Question 27

Basic mechanism of Golgi tendon organ and muscle spindle

Answer 27

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

Question 28

Reflexes: stretch reflex, reciprocal inhibition and how they work

Answer 28

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

Question 29

Newton’s laws of motion

Answer 29

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

Question 30

Classes of levers

Answer 30

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)

Question 31

Forces
i. Linear
ii. Concurrent
iii. Resultant

Answer 31

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

Question 32

Vector
Moment arm
Torque

Answer 32

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.

Question 33

Stability and its components, principles of stability

Answer 33

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

Question 34

Be able to draw the basic form of a joint with motion (bones, axis, line of pull, moment arm