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Chapter 4
The Language of the Health-Care Professions
From R. C. Schafer, DC, PhD, FICC's best-selling book:
“The Chiropractic Assistant”
The following materials are provided as a service to our profession. There is no charge for individuals to copy and file these materials. However, they cannot be sold or used in any group or commercial venture without written permission from ACAPress.
All of Dr. Schafer's books are now available on CDs, with all proceeds being donated
to support chiropractic research. Please review the complete list of available books.The Universal Language of HealthCare: Why It Is Necessary Phonetics: The Quick Way to Grasp Meanings How the Words Are Formed Common Latin and Greek Word Roots Common Latin and Greek Prefixes Common Latin and Greek Suffixes Singulars and Plurals Traditional Style Modern Style Common Anatomical Terms Terms of Patient Position Terms of Direction and Location The Planes of the Body in Biodynamics Structural Motion Describing Positions in Space Axes Linear and Circular Motion Degrees of Joint Movement Freedom Combined Movements Plane Motion The Instantaneous Axis of Rotation Out-of-Plane Motion Terms of Motion Common Diagnostic and Procedural Terms Background Review Terminology
Chapter 4: The Language of the Health-Care Professions
When more than one person is involved in any task, good communication is basic for success. Thus, a sound foundation in chiropractic terminology is an important functional skill to be possessed by any chiropractic assistant. It is a requisite to becoming an important asset to the office.
If a CA’s duties include taking dictation of case histories, examination findings, or narrative reports, she must know how to record scientific terms in shorthand and know how to spell them accurately. A good medical dictionary will be an important reference. Even if dictation is not required, she still must know what the doctor means when certain terms are used. He will expect his assistants to have a fundamental grasp of commonly used medical terms, abbreviations, and acronyms.
Do not enter this study lightly. On the other hand, do not let yourself be appalled by the formidable and specialized vocabulary used in health care. The learning of professional terms will not come overnight. It will extend the entire length of your career as new and unfamiliar words are confronted.
THE UNIVERSAL LANGUAGE OF HEALTH CARE: WHY IT IS NECESSARYIt would not be unusual if you found many words used in the first three chapters of this program strange or at least unknown. When you undertake the transposition from lay person to chiropractic assistant, you are faced with an entirely new language that must be mastered so the transition be successful. The most efficient method to accomplish this is by securing an understanding of basic word roots, prefixes, and suffixes used in the formation of technical words and gaining an understanding of the meaning of commonly used abbreviations and acronyms. Study and repetitive use is the way to mastery.
A fundamental knowledge of anatomy (structure) and physiology (function) will be of great assistance in learning terminology. A basic understanding of human anatomy and physiology is offered in the following chapter. This chapter will prepare you for the terminology of those and other clinical subjects. While professional terms may at first seem strange, you will see their purpose in this and following chapters.
PHONETICS: THE QUICK WAY TO GRASP MEANINGS
In studying the terminology of any science as in learning any language, phonetics or word sound plays an important role. While you will never need to know how to spell or pronounce every word in your reference dictionary, you will be required to be familiar with common terms and know where and how to look up unfamiliar terms. Phonetics and an understanding of prefixes and suffixes will be helpful, if not necessary, to do this.
There are two simple rules for correct pronunciation of scientific terms. They are based on the syllable breakdown of the word and the occurrence of vowels (a, e, i, o, u):
If the vowel is not followed by a consonant in the same syllable, it has the long sound; eg, the word abdomen (ab-do-men). Here the “o” in “do” has the long low sound.
If the vowel is followed by a consonant in the same syllable, it has the short sound; eg, the word abdominal (ab-dom-i-nal). Here the “o” in “dom” has the short higher sound as in “Tom.”
HOW THE WORDS ARE FORMED
As chiropractic vocabulary is studied, the student will find it made largely of many variations of various roots, prefixes, and suffixes in different combinations. Thus the number of word parts necessary to learn is not so great as one would suspect.
Most technical words used in chiropractic terminology come from the root languages (Greek and Latin). Some are pure translations; others are combined forms of Greek and Latin. While the number of English words is enlarging, prefixes and suffixes usually remain Greek or Latin.
Besides Greek and Latin, other languages have had their influence. Words such as alcohol, alkali, camphor, and tartar are derived from Arabic. Many simple anatomical terms such as arm, back, bladder, blood, finger, foot, gut, hair, hand, knee, liver, lung, mouth, neck, ache, fat, and sick are Anglo-Saxon in origin. Other monosyllable terms such as ill, leg, and skin are of Scandinavian descent. Words such as chancre, cretin, fontanelle, grippe, malaise, poison, role, cul de sac, grand and petite mal and tic douloureux come from the French, as do such Americanized terms as goiter, gout, malinger, jaundice, ointment, and physician. Some examples of Greek-French terms are surgeon, plaster, migraine, and palsy. From the Italian we have gained the words influenza and malaria, and from the Dutch, cough, litmus, and splint. The Germans, Persians, Chinese, and Spanish also have contributed their share.
It is not unusual for a student new to health science terminology to recoil in fright when confronted with a term such as hemangioendothelioblastoma. But once the roots, prefixes, and suffixes making such compounds are learned, what seems at first impression to be unintelligible soon becomes quite clear.
For this reason, commonly used prefixes, suffixes, and word elements should be studied diligently. The first step is to break a compound term into its parts. For example, view the example given above ashem + angio + endothelio + blast + oma
This aid spelling, pronunciation, and remembering. Once the definitions of these units are known, the meaning of the compound word is understood.
hem – blood angio – vessel endothelio – endothelium blast – primitive cell (or, germ call) oma – tumor
Thus, Hemangioendothelioblastoma translates as:a primitive cell tumor located in the endothelium of a blood vessel:
Other examples of how words are made and their literal meanings are cardiogram, meaning tracing of heart action, from cardio (heart) + gram (picture); colitis, meaning inflammation of the lower intestine, from col (colon) + itis (inflammation); and leukocytes, meaning white blood cells, from leuko (white) + cytes (cells).
COMMON LATIN AND GREEK WORD ROOTS
Table 4.1 lists many common Latin and Greek roots used in chiropractic terminology. Some word elements are frequently placed before other word elements as prefixes or after other elements as suffixes. For euphony, a vowel or a consonant is sometimes added to or subtracted from word elements in combination.
Refer to Table 4.1. The root is given first; then a brief definition follows.
Note: Because of the length of the following table,
you may want to jump to the next section:
Common Latin and Greek Prefixes
Table 4.1. Common Latin and Greek Roots
A Root Definition abdominus
abdomen
acantha
spine
acousia
hearing
acro
extremity
actin
ray
acuo
sharp, sudden
aden
gland
adeps
fat
adit
entrance, approach
aer
air
ala
wing
alba
white
alex
to protect
algia
pain
ama
together
ana
to build up
andro
man
anglo
vessel
anima
soul
ankylo
loop, adherence
anom
irregular
ansa
handle
antero
before
anthrop
man
antrum
cavity
anulus
circular
aqua
water
arche
beginning
archo
anus
arcus
bow, arc
arthro
joint
articulus
joint
astro
star
atmo
vapor, air
atrophy
a wasting away
audio
to hear
auris
the ear
auto
self
B Root Definition bacter
rod
baro
weight
bary
heavy
basis
foundation
bilis
bile
blos
life
blast
germ
bovine
cow, ox
brachlon
arm
brachium
arm
brachy
short
brady
slow
brevis
short
bromos
stench
bronchus
bronchial tube
bubon
groin
bursa
sac, pouch
C Root Definition caco
bad, poor, sick
calor
heat
caput
head
cardio
heart
carno
flesh
cartilago
gristle
cata
down
cauda
tail
cavum
cavity
cele
hernia
celia
abdomen
entesis
puncture
cephal
head
chir(o)
hand
chole
bile
chondra
cartilage
chroma
color
chyle
juice
cide
to kill
clast
breaking down
color
hew
colp
vagina
cor
heart
corpus
body
costa
rib, side
crico
ring
erotic
pulsation
crucis
the cross
crus
leg
crux
the cross
cry
cold
crypt
hidden
cutis
skin
cyano
blue
cyna
dog
cyte
cell
D Root Definition dacry
tear
dactyl
finger
deca
ten
demo
people
dens
tooth
derma
skin
dexia
on the right
dexter
right
digit
finger, toe
diplo
double
dolor
pain
durus
hard, lasting
dynia
ache, pain
dys
difficult, painful
E Root Definition ectasis
dilatation of
ecto
without, outside
ectopy
displacement of
embryo
to grow within
emia
blood
endo
within
ensis
sword
entero
intestine
equus
equal
erythro
red
esthesia
feeling, touch
eu
good, healthy
exo
outside, without
F Root Definition febris
fever
femina
woman
Fibra
fiber
fila
thread
flex
bend
G Root Definition galactia
milk
gastr
the stomach
gen
to beget
genu
knee
germen
germ, sprig
gingiva
the gum(s)
glossa
tongue, speech
glyco
sugar
graph
to write, record
gravi
weighty, serious
gyne
woman, female
gyros
circle
H Root Definition hala
breath, air
helio
the sun
hema
blood
hepat
the liver
heter
other, different
hidro
perspiration
histo
tissue
homo
like, same
humerus
shoulder
hydro
water
hygea
health
hypno
sleep
hyster
womb
I Root Definition icthy
fish
idio
self
ileum
distal small intestine
ilium
hip bone
intestinum
intestine, entrail
ipso
same
iso
equal
J Root Definition jecur
liver
juxta
near
K Root Definition keras
horn, cornea
kine
motion
L Root Definition lachryma
tear
lact
milk
later
side
lati
broad
lave
wash
lepid
scale, scaly
lepsy
spasm, seizure
leuko
white
lexia
word
lien
the spleen
lingua
tongue
lipa
fat
lith
stone, calculus
logue
speech
luna
moon
lysis
to dissolve, breakdown
M Root Definition macro
great, long
mal
bad, painful
malacia
softening
mamma
breast
mania
madness
mas
man, male
mast
breast
medicamentum
medicine
medio
middle
mega
large, great
megalo
large, great
melano
black
meno
month
mens
mind
mensis
month
mentis
mind
meso
middle
meta
between, after, beyond
meter
measure
metro
the uterus
micro
tiny, minute
mis
bad, poor, dislike
mono
single, alone, one
morbus
disease
mortis
death, dead
muco
mucus
multi
many
musculus
muscle
myelo
marrow
myo
muscle
N Root Definition nano
dwarf
nasus
nose
natus
birth
necro
death
neo
new
nephr
kidney
nervus
nerve
neuro
nerve
nidus
nest
niger
black
nocte
night
nomen
name
naso
nose
nosto
to return, go
novus
new
nychia
fingernail, toenail
O Root Definition ob
against, obstructive
odont
tooth
odor
smell
olig
little, sparse, few
omni
all
onoma
name
oophor
ovary
opthalma
the eye
ora
mouth
orch
testicle
ortho
straight, regular
os
mouth
osma
odor
osteo
bone
ot
ear
ovum
egg
P Root Definition pachy
thick
paleo
old, ancient, past
pan
all
para
to bear
paries
wall
partum
to give birth to
path
disease, disorder
pedi
child
pedis
foot
penia
poverty, poorness
pexy
fixation
phagy
to eat
pharmac
medicine, drug
phil
to love
phleb
vein
phobia
morbid fear
phone
voice, sound
photo
light
phrasia
utterance, speech
phren
mind, head, skull
phylaxis
anti-infection
physi
nature
plasia
toform
pnea
to breathe, breath
pneumo
lung
podia
foot
polio
gray
poly
many, excessive
procto
anus
pseudo
false, mimic
psyche
mind, soul, spirit
pteryg
wing
ptya
sputum, salvia
pulmo
lung
pulsus
pulse, stroke, beat
puter
rotten, putrid
pyelo
trough, basin
pyo
pus
pyr
fire
pyreto
fever
Q Root Definition quadri
four
R Root Definition rachis
spine
ramus
branch
rar
thin, rare, sparse
ren
kidney
rheo
current
rhin
the nose
ruber
red
S Root Definition salping
tube
salpinx
tube
sanguis
blood
sanitas
health
sapro
putrid
sarco
flesh
sarx
flesh
schist(o)
to separate, split
schiz
to divide, split
scler
hard
scopy
observation of
scota
darkness
sect
tocut
sial
saliva
sito
food
soma
body
somnus
sleep
spasm
seizure, convulsion
sphen
wedge
sphygma
pulse, throb
spina
spine
spiritus
spirit
splanchna
organ, viscus
spondy
vertebra, spine
squama
ascale
staphyl
grape
stasis
stopping, checking
stere
solid
steth
chest
stoma
mouth
stomach
unus
sudor
perspiration
super
over, abnormal
supra
above
T Root Definition tachy
swift
tact
touch
tend
tendon
teno
tendon
testis
testicle
tetra
four
thana
death
thenia
strength, power
theo
god, deity
therapy
treatment
therm
heat, temperature
thorax
chest
thrombo
blood clot
thyro
shield, thyroid
tocia
childbirth
toco
childbirth
tonus
tone, sound
tricho
hair
trophy
nutrition, growth
U Root Definition ula
gum
ultra
over, beyond, excess
uria
urine
uter
womb
V Root Definition vas
vessel
ven(e)
vein
vertebra(l)
spine, backbone
X Root Definition xanth
yellow
xero
dry
xylo
wood
Z Root Definition zoo
animal
zymo
to ferment
Note: Because of the length of the following table,
you may want to jump to the next section:
Common Latin and Greek Suffixes
Table 4.2. Common Prefixes and Examples of Use
Prefix Meaning Example Definition a-
without, not, absence of
achromia
without color
ab-
from, away from, negative
abduct
draw away from
abdomin-
abdomen
abdominoscopy
direct stomach inspection
acid-
sour
aciduric
pertaining to acidic urine
acro-
extremity, apex, extreme
acromegaly
extremity hyperplasia
acou-
hearing
acousma
auditory hallucination
actin-
ray, ray like
actinoid
resembling a ray
acr-
extremity
acromegaly
enlarged extremities
act-
do, drive, act
action
an act, deed, or performance
actin-
ray, radius
actinotherapy
therapy by light or x-rays
acu-
needle
acupoint
meridian point
ad-
to, toward, on, near, by
adoral
toward the mouth
aden-
gland, glandular
adenoma
gland tumor
aden(o)-
gland, glandular
adenodynia
ache in a gland
adip-
fat
adipocellular
pertaining to fatty cells
aer(o)-
air
aerophagia
swallowing of air
alb-
white
albinism
whiteness
all-
other, different
allergy
induced sensitivity
alve(o)-
cavity, socket, channel
alveoalgia
dry socket pain (eg, tooth)
ama-
together
amarthritis
multijoint arthritis
ambi-
both, around
ambivalence
simultaneous opposites
amph(i)-
both
amphibolia
period of doubtful diagnosis
amyl(o)-
starch
amylosuria
amylase in the urine
an-
without, not, absence of
anorexia
absence of appetite
ana-
up, back again, increase
anabolism
constructive metabolism
andro-
man, male
androphobia
morbid fear of males
angi(o)-
vessel (blood)
angiolith
stone in a blood vessel wall
anima-
life, spirit, soul
animate
to quicken, make alive
ankyl(o)-
loop, bend, adherence
ankylosed
joint immobility, consolidation
anomalo-
irregular
anomalotrophy
abnormality of nutrition
ante-
before in time or place
antepartum
before delivery (childbirth)
anter-
before, front
anteriorly
toward the front
anthrop-
man, mankind,
anthropoid
resembling man, ape
ant(i)-
against, counter
antidote
against poison
antr-
cavern
antrodynia
pain from a cavity or viscus
apo-
separation, away from
apophysis
bone outgrowth or projection
aqua-
water
aquatic
inhabitant of water
arch-
beginning
archetype
original model or pattern
archi-
first
archineuron
first nerve starting an impulse
arch(o)-
rectum
archoptoma
prolapsed portion of rectum
arthr(o)-
joint, articulation
arthritis
inflammation of joint(s)
articu-
joint
articulation
union/junction between bones
astro-
star
astrocyte
star-shaped cell
atmo-
vapor, air, breath
atmosphere
mass of surrounding air
audi(o)-
to hear
auditory
pertaining to hearing
auri-
the ear
auriform
ear shaped
auto-
self
autotoxin
self-made organic poison
B Prefix Meaning Example Definition bacter-
rod
bacteria
rod-shaped microorganisms
baro-
weight
barograph
air weight or pressure chart
bary-
heavy
baryglossia
thick speech
basi-
base, lower part
basilar
pertaining to the foundation
bi-
two, twice, double
biceps
muscle with two heads
bili-
bile
bilirubin
ruby-colored bile pigment
bio-
life
biology
science of life
blast-
germ
blastolysis
destruction of germ substance
bovin-
cow, ox
bovinoid
resembling a cow or an ox
brachi-
arm
brachialgia
severe arm pain or ache
brachy-
short
brachydactyly
short fingers and toes
brady-
slow
bradycardia
abnormally slow heart beat
brevi-
short
breviflexor
any short flexor muscle
bromo-
stench, foul odor
bromopnea
foul breath, halitosis
bronch-
bronchial tubes
bronchitis
bronchial inflammation
bubon-
groin
bubonalgia
pain or ache in the groin
burs-
sac, pouch
bursitis
inflammation of a bursa
C Prefix Meaning Example Definition caco-
bad, ill
cacogeusia
a bad or poor taste
calor-
heat
calorie
a unit of heat measurement
capi-
head
capitate
head shaped
cardio-
heart
cardiostenosis
narrowing of heart chambers
carni-
flesh
carnivora
flesh-eating animals
cata-
down, lower, under
catarrh
a down-flow of mucus
caud-
tail, tail like
caudate
having a tail
cephal-
head
encephalitis
brain inflammation
cervic-
neck
cervicitis
inflammation of the cervix
chondra-
cartilage, gristle
chondralgia
pain in a cartilage
chromat-
color
chromatology
science of color
chylo-
juice
hylothorax
effused chyle in the chest
circum-
around, about
circumduction
circular movement of extremity
co-
together, with
coalesce
grow together
com-
together, with
combination
a united set of things
con-
together, with
congenital
existing since birth
contra-
against, counter, opposite
contraception
against conception, pregnation
cor-
heart
cordiform
heart shaped
crico-
ring
cricoid
resembling a ring
cry-
cold
cryesthesia
anesthesia produced by cold
crypt-
hidden
cryptorchidism
undescended testicle
cut-
skin
cutitis
inflammation of the skin
cyan-
blue
cyanosis
bluish skin
cyn-
dog
cynophobia
morbid fear of dogs
cyto-
cell
cytopenia
poverty of blood cells
D Prefix Meaning Example Definition dacry(o)-
tear
dacryorrhea
excessive tear discharge
dactyl-
finger
dactylogram
fingerprint
de-
down, away from, removal
demote
lower in rank, class, or grade
deca-
ten
decameter
ten meters
deci-
one-tenth
decimeter
one-tenth of a meter
demo-
people
demotic
pertaining to people
dent-
tooth
dentoid
resembling a tooth
dermat-
skin
dermatitis
skin inflammation
dexio-
on or toward right side
dexiotropic
curving from left to right
dextro-
right
dextromanual
right-handed
di-
double, twice
dicrotic
double pulse beat
dia-
through, apart, between
dialysis
passing through a membrane
digi-
finger, toe
digital
pertaining to a finger or toe
diplo-
double, twin
diplopia
double vision
dis-
apart, away from
disease
no ease, away from ease
dolor-
pain
dolorous
painful, expressing pain
dors-
back, toward the back
dorsal
pertaining to the back
dura-
hard, solid, compact
dura mater
outermost tough meninges
dys-
difficult, bad, painful
dysmenorrhea
painful menstruation
E Prefix Meaning Example Definition ec-
out of, from
eccentric
away from normal or average
ect(o)-
outside of, without
ectoderm
external layer of skin
electro-
electric
electrotherapy
therapy by electric current
en-
in, within
encephalia
within the skull
end(o)-
within, in
endogastric
within the stomach
ensi-
sword
ensiform
sword shaped
enter(o)-
intestine
enteritis
intestinal inflammation
ento-
within, inner
entocyte
contents within the cell
epi-
on, over, upon
epicondyle
bony prominence on a condyle
equi-
equal
equilibrium
equally balanced
erythro-
red
erythrocyte
red blood cell
esthesio-
touch, sensation, feeling
esthesiogenic
producing sensation
eu-
good, well, pleasant
euphoria
state of joy or well being
evi-
egg
oviduct
Fallopian duct (egg canal)
ex-
away from, out, outside
excentric
away from the center
exo-
outside, out, without
exocardial
external to the heart
extra-
outside of, beyond
extraspinal
apart from the spine
F Prefix Meaning Example Definition febri-
fever
febriphobia
morbid fear of catching a fever
fil-
thread
filiform
thread-like shape or character
flex-
bend
flexure
curvature, bend of a part
G Prefix Meaning Example Definition galact-
milk
galactose
milk sugar
gastr-
stomach
gastritis
inflammation of stomach lining
gen-
to give birth to, beget
genetics
science of heredity
germi-
germ, sprig
germicidal
destructive to germs
gingi-
the gum
gingivitis
inflammation of the gums
gloss(o)-
tongue
glossolysis
paralysis of the tongue
glyco-
sugar
glycopenia
deficiency of sugar
gravi-
weight, serious, heavy
gravid
pregnant, heavy with child
gyn-
woman, female
gynecology
study of female diseases
gyr-
circle
gyrospasm
spasmotic rotary head motions
H Prefix Meaning Example Definition hali-
breath, air
halitus
an exhaled breath
helio-
the sun
heliotherapy
treatment by sun rays
hem-
blood
hemorrhage
gushing forth of blood
hemi-
half
hemiparesis
paralysis of half the body
hepat-
the liver
hepatitis
inflammation of the liver
hetero-
other, different
heterochromic
composed of various colors
hidro-
sweat
hidrosis
perspiration
hist(o)-
tissue
histolysis
destruction of tissue
homo-
same, like
homogenesis
of same character throughout
humer-
shoulder
humeral
relating to the shoulder
hydro-
water, fluid
hydrothorax
fluid in the chest cavity
hyper-
over, beyond, excess
hyperostosis
overgrowth of bone
hypno-
sleep
hypnosis
sleep-resembling state
hypo-
under, deficiency
hypoplasia
incomplete growth
hyster-
womb, uterus
hysterectomy
surgical removal of the uterus
I Prefix Meaning Example Definition icthy-
fish
icthyderm
scaly (fish-like) skin
idio-
self
idioneurosis
neurosis arising from nerves
ileo-
ileum
ileocecal
pertaining to ileum and cecum
ilio-
ilium, flank
iliospinal
relating to ilium and spine
im-
not
impermeable
unable to be permeated
in-
within, into, not
incise
to cut into
infra-
beneath, below
inframandibular
below the jaw
ino-
fiber, tendon
inopolypus
a fibrous polyp
inter-
between, among
intercostal
between the ribs
intestin-
entrail, intestine
intestinotoxin
interotoxin
intra-
within, into
intraspinal
within the spine
intro-
into, in, inward
introspect
to look within
ipsi-
same
ipsilateral
on the same side
iso-
equal
isotonic
of the same or uniform tone
J Prefix Meaning Example Definition jeco-
liver
jecoral
relating to the liver
juxta-
near, nearby, close to
juxtaspinal
near the spine
K Prefix Meaning Example Definition kerat-
horn, horny
cornea
similar to a horn
kinesi-
motion
kinesiology
study of motion
L Prefix Meaning Example Definition lachry-
tear
lachrymose
tearful, saddening, weeping
lact-
milk
lactose
milk sugar
later(o)-
side
lateroflexion
bending to the side
lati-
broad
latissimus
a broad muscle
lav-
wash
lavipedium
foot bath
lepid-
scale, scaly, fish-like
lepidosis
skin resembling that of a fish
leuko-
white
leukocyte
white blood cell
levo-
left, to the left
levorotation
turning to the left
lexi-
word
lexical
pertaining to the vocabulary
lien-
the spleen
lienocele
splenic hernia
lingu-
tongue
linguiform
tongue shaped
lip(o)-
fat
lipoma
fatty tumor
litho-
stone, calculus
lithotripsy
crushing of stones in bladder
luna-
moon
lunate
moon shaped
M Prefix Meaning Example Definition macro-
long, great, large
macrosis
increase in size, bulk, length
mal-
bad, painful, poor
malnutrition
poor nutrition
mamm-
breast
mammectomy
breast amputation
mas-
man, male
masculation
development of male features
mast-
breast
mastitis
inflammation of mammary gland
medi-
medicine
medicator
one who administers drugs
medi(o)-
mid, middle
mediolateral
relating to the center and side
mega-
large, great
megalosplenic
enlarged spleen
melan(o)-
black, ebony
melanocarcinoma
a black cancer
meno-
month
menopause
cessation of monthly menses
ment-
mind
mentality
mental power
mens-
month
menstruation
monthly discharge of menses
meso-
middle
mesocephalic
medium-sized head
meta-
beyond, change, between
metastasis
transition, going more
metro-
uterus
metroscope
intrauterine inspection device
micro-
small, minute
microorganism
organism invisible to naked eye
mis-
bad, dislike
misopedia
dislike of children
mono-
one, single, alone
monochromatic
of one color
morbi-
disease
morbific
disease producing
muco-
mucus
mucumembraneous
having a mucous membrane
multi-
many
multipara
woman having many children
musculo-
muscle
musculophrenic
pertaining to diaphragm muscle
myelo-
marrow
myelomalacia
softening of bone marrow
my(o)-
muscle
myotonia
muscle tone
N Prefix Meaning Example Definition nano-
dwarf
nanocephalous
dwarf-like cranium
nas-
nose
nasoseptitis
inflammation of nasal septum
necro-
death
necrosis
death of a part or tissue
neo-
new
neoplasm
new tissue formation, growth
nephr-
kidney
nephralgia
kidney pain
nervi-
nerve
nervimotor
pertaining to a motor nerve
neuro-
nerve
neurocyte
nerve cell
noct-
night
noctambulism
sleep walking
nomen-
name
nomenclature
classification by name
non-
not, anti, against
nonstriated
without striations
noso-
disease
nosogenesis
the progression of disease
nost
home, to go, to return
nostalgia
homesickness
nov-
new
novice
newcomer
O Prefix Meaning Example Definition ob-
against, in the way of
obdurate
stubborn
odont-
tooth
odontotechny
dentistry
olig-
little, few
oligocholia
insufficient bile
om-
shoulder
omarthritis
shoulder arthritis
omni-
all
omnifarious
of all types, classes, or kinds
onom-
name
onomatology
the study of names
oophor-
ovary
oophoritis
inflammation of an ovary
ophthalm-
the eye
ophthalmopathy
disease of the eye
opistho-
backward, behind
opisthoporeia
involuntary walking backward
orch-
testicle
orchiocele
hernia of the testicle
ortho-
regular, normal, straight
orthotonic
correct tone
ora-
mouth
orad
toward the mouth
oste(o)-
bone
osteomyelon
bone marrow
ot-
ear
otalgia
earache
P Prefix Meaning Example Definition pachy-
thick
pachyemia
thick blood
paleo-
old, ancient
paleogenetic
originated long ago
pan-
all, every
pandemic
widespread epidemic
para-
near, by the side of
parallel
side by side
pariet-
wall
parietal
pertaining to wall of a cavity
partu-
give birth to, bring forth
partuition
child bearing
path-
disease
pathology
the study of disease
ped-
child
pediatrics
science of childhood diseases
pedi-
foot
pediferous
having feet
per-
through, throughout
percussion
to strike through
peri-
around
pericanalicular
around a canal
phago-
to eat
phagocyte
cell that ingests bacteria
pharm-
medicine, drug
pharmacotherapy
treatment by medication
phleb-
vein
phlebitis
inflammation of vein lining
phon-
sound, voice
phonetic
relating to the voice
photo-
light
photophobia
fear of light
phren-
mind, head
phrenopathy
any mental disease
physi-
nature
physiotherapy
treatment by natural forces
pleuro-
side, rib
pleurocentrum
lateral part of the spine
pluri-
more, several
plurimenorrhea
increased menstrual frequency
pneumo-
lung
pneumopathy
any lung disease
pod-
foot
podarthritis
arthritis of the foot
polio-
gray
poliosis
premature gray hair
poly-
many, excessive
polyuria
frequent urination
post-
after, behind, late
posttherapy
after treatment
pre-
before, front of, early
prenatal
before birth or delivery
pro-
affirmative, according to
procreate
to generate
proct(o)-
rectum
protocele
rectal hernia
proto-
first
protoplasm
early form of living matter
pseudo-
false
pseudocyesis
false pregnancy
psych-
mind, soul, spirit
psychogenic
originating in the mind
pteryg-
wing
pterygoid
resembling a wing, wing shaped
ptya-
sputum, saliva
ptyalism
excessive flow of saliva
pulmo-
lung
pulmonary
relating to a lung
puls-
pulse, stroke, beat
pulsation
throbbing or rhythmical beat
putre-
putrid, rotten, decayed
putrefactive
relating to decomposition
pyelo-
trough, basin
pyelogram
kidney x-ray film
pykn-
thick, compact, frequent
pyknic
short, thick, stocky build
pyo-
pus
pyomyositis
purulent muscle inflammation
pyro-
fire, fever
pyrogenetic
fire or fever producing
pyreto-
fever
pyretograph
fever chart
Q Prefix Meaning Example Definition quadri-
four
quadrifid
separated into four parts
R Prefix Meaning Example Definition rach-
spine
rachioplegia
spinal paralysis
rami-
branch
ramiform
branch like, tree shaped
rar-
thin, rare, sparse
rarefaction
making thinner, less dense
re-
again, back, against
recreation
to create again, restore
reni-
kidney
renipuncture
surgical kidney puncture
retro-
behind, back, backward
retroflexed
bent backward
rhin-
the nose
rhinitis
nasal inflammation
rubi-
red
rubicund
blushing, red like
S Prefix Meaning Example Definition salping-
tube
salpingitis
inflammation of fallopian tube
sangui-
blood
sanguinary
bloody
sanit-
health
sanitarian
a hygienist
sapro-
putrid
saprogenic
producing decay
sarco-
flesh
sarcoma
connective-tissue cancer
schiz-
to divide, split, fissure
schizophrenia
split personality
scler-
hard, indurated
sclerosis
condition of hardening
scoto-
darkness
scotophobia
fear of the dark
sect-
to cut
sectile
able to be cut
semi-
half
semilunar
half-moon shape
sero-
serum
serous
watery, serum like
sial-
saliva
sialochesis
salivary flow suppression
sit-
food
sitology
study of food, nutrition
soma-
body
somatic
pertaining to the body
somni-
sleep
somnipathy
any sleep disorder
spasmo-
seizure, convulsion
spasmodyspnea
difficult or jerky breathing
sphen-
wedge
sphenoid
wedge shaped
sphygmo-
pulse
sphygometer
pulse-measuring instrument
spino-
spine
spinograph
spinal x-ray film
spondylo-
vertebra, spine
spondylosis
degeneration of vertebrae
squamo-
a scale
squamoid
scale like, resembling a scale
steno-
contracted, narrow
stenocoriasis
pupil contraction
stereo-
solid
stereodynamics
motion of solid bodies
steth-
chest
stethoscope
chest examination device
stomat-
mouth
stomatitis
inflammation of the mouth
sub-
less, under, below
subcutaneous
under the skin
sudor-
perspiration
sudorific
causing sweat
super-
over, above, excessive
supercilia
above the eyelid or eyebrow
supra-
above, upon, on
supraorbital
above the eye socket
sym-
together, with
symbiotic
living together
syn-
together, with
syndactylism
webbed fingers or toes
T Prefix Meaning Example Definition tachy-
swift, fast, rapid
tachycardia
abnormally rapid heart beat
tact-
touch, sensation
tactile
pertaining to touch
tend-
tendon
tendotomy
surgical cutting of a tendon
test-
testicle
testitis
inflammation of a testicle
tetra-
four
tetragenous
separated into four parts
thana-
death
thanology
the study of death
theo-
god, deity
theomania
fanaticism
thera-
to heal, treat
therapeutics
the science and art of healing
thermo-
temperature, heat
thermometer
heat-measuring instrument
thoraco-
chest
thoracodynia
chest ache
thrombo-
blood clot
thrombostasis
circulation stopped by clot
thyro-
shield
thyroid
resembling a shield
toco-
childbirth
tocology
obstetrics
topo-
place, location, site
topographic
describing a specific area
tox-
poison
toxemia
intoxication
toxi-
poison
toxipathy
toxicosis (poisoning)
toxic(o)-
poison
toxicogenic
producing toxins
toxo-
poison
toxophilic
highly susceptible to poison
trans-
across, through
transudate
fluid seeping thru membrane
tri-
three, thrice
triad
group of three
tricho-
hair
trichopathy
a disease of or involving hair
U Prefix Meaning Example Definition ul-
gum
ulatrophy
shrinking of gum tissue
ultra-
over, excess, beyond
ultramarine
beyond the sea
un-
not
unconscious
not conscious
ungu-
nail
ungual
relating to body’s nails
uni-
one
unilateral
one sided, on one side
utero-
womb
uteroplasty
repair of the uterus
V Prefix Meaning Example Definition vaso-
vessel
vasoparesis
vasomotor paralysis
veni-
vein
veniplex
a venous plexus
ventro-
front, anterior
ventroptosis
falling abdomen
vertebr-
vertebra, spine
vertebrarium
vertebral column
vesic-
blister, bladder
vesicocele
hernia of the bladder
X Prefix Meaning Example Definition xanth-
yellow
xanthodont
yellowish teeth
xero-
dry
xerosis
abnormal dryness
Z Prefix Meaning Example Definition zoo-
animal
zoology
the study of animals
zymo-
to ferment
zymogenic
producing fermentation
Note: Because of the length of the following table,
you may want to jump to the next section:
Singulars and Plurals
Table 4.3. Common Suffixes and Definitions
Suffix Definition -acusis
hearing
-age
to move
-agogue
inducing
-agra
catching, seizure
-al
characterized by
-algia
pain, ache
-ase
enzyme
-atrics
the practice of
C Suffix Definition -cele
swelling, tumor, hernia
-cian
one who
-cide
causing death, killer
-cle
little
-cocle
chamber, ventricle
-cosis
condition or state of
-cule
little
-cyst
bladder, bag
-cyte
cell
E Suffix Definition -ectomy
excision, surgical removal
-emia
blood
-en
in, into
-ence
condition, state of being
F Suffix Definition -form
resembling, like, same
-fuge
driving away
G Suffix Definition -genic
origin, producing
-genetic
origin, producing
-gram
tracing, picture
-graph
record, chart
I Suffix Definition -iasis
condition of
-ic
pertaining to, relating to
-ical
pertaining to, relating to
-icosis
condition or state of
-itis
inflammation
K Suffix Definition -kinesis
motion, movement
-kinetic
motion, dynamic
L Suffix Definition -logy
study of, science of
-lysis
setting free
M Suffix Definition -malacia
softening
-meter
measure
O Suffix Definition -odynia
pain, ache
-oid
like, resembling
-ology
study of, science of
-oma
tumor, neoplasm
-osis
condition, state, process
-ostomy
opening into for drainage
-otomy
to cut into, incise
-ous
full of
P Suffix Definition -pathy
disease of, feeling
-plasty
repair
-penia
lack or poverty of
-peutics
science of
-phage
consuming, eating
-plastic
molded
-plegia
paralysis
-practic
the practice of or by
-ptosis
falling, prolapse
R Suffix Definition -raphy
suture of
-rrhagia
sudden flow
-rrhea
discharge, flow
-rrhexia
rupture of
S Suffix Definition -scopy
direct examination of
-stomy
opening
T Suffix Definition -tomy
incision of, cut
-trophy
nutrition
-tropy
a turning
U Suffix Definition -uria
urine
Z Suffix Definition -zyme
ferment
Note: Because of the length of the following tables,
you may want to jump to the next section:
Modern Style
Table 4.4. Greek and Latin Singular and Pleural Word Endings
Singular Word Ending Pleural Word Ending Singular Word Example Pleural Word Example a
ae
bursa
bursae
ad
ades
gonad
gonades
cus
cera
viscus
viscera
er
era
cadaver
cadavera
ex, ix
ices
apex
apices
ia
es
esthesia
estheses
is
es
axis
axes
is
ides
ascaris
ascarides
ma
mata
adenoma
adenomata
men
mina
sudamen
sudamina
s
sa
vas
vasa
s
des
glans
glandes
s
tes
albacans
albacantes
sis
ses
diagnosis
diagnoses
u
ua
cornu
cornua
um
a
bacterium
bacteria
um
i
dorsum
dorsi
us
i
bacillus
bacilli
us
ora
corpus
corpora
x
a
nox
noxa
Table 4.5. Table 4.5. Examples of Traditional
Greek and Latin Singular and Plurals
A Singular Plural addendum
addenda
aden
adena
adenoma
adenomata
ala
alae
albacans
albacantes
amygdala
amygdalae
antenna
antennae
antiad
antiades
antrum
antra
apertura
aperturae
apex
apices
aponeurosis
aponeuroses
appendix
appendices
aqua
aquae
arcus
arcus
ascaris
ascarides
ascus
asci
atrium
atria
axis
axes
B Root Definition bacillus
bacilli
bacterium
bacteria
bronchus
bronchi
bulla
bullae
bursa
bursae
C Root Definition cactus
cacti
cadaver
cadavera
calcaneum
calcanea
calculus
calculi
calls
calices
cantharis
cantharides
canthus
canthi
cornu
cornua
corpus
corpora
crisis
crises
cuniculus
cuniculi
D Root Definition dens
dentes
diagnosis
diagnoses
diaphoreticus
diaphoretici
diastema
diastemata
digitus
digiti
dorsum
dorsi
E Root Definition echolatus
echolati
enema
enemata
ensis
enses
epididymis
epididymides
esthesia
estheses
F Root Definition fibroma
fibromata
filix
filices
filum
fila
flagellum
flagella
focus
foci
fornix
fornices
fossa
fossae
G Root Definition glans
glandes
gonad
gonades
gonococcus
gonococci
gyrus
gyri
I Root Definition ilium
ilia
index
indices
K Root Definition keratosis
keratoses
L Root Definition labium
labia
lamina
laminae
loculus
loculi
locus
loci
M Root Definition medium
media
mucosa
mucosae
N Root Definition nodus
nodi
nox
noxa
O Root Definition os
ora
ovum
ova
P Root Definition papilla
papillae
pathema
pathemata
pes
pedes
petechia
petechiae
pilula
pilulae
polypus
polypi
R Root Definition ramus
rami
S Root Definition septum
septa
sequestrum
sequestra
serosa
serosae
spasmus
spasmi
spectrum
spectra
speculum
specula
stoma
stomata
sudamen
sudamina
sulcus
sulci
T Root Definition tarsus
tarsi
tela
telae
tinctura
tincturae
toxicosis
toxicoses
typha
typhae
U Root Definition ulcus
ulcera
V Root Definition varix
varices
vas
vasa
vesicule
vesiculae
vis
vires
viscus
viscera
vomica
vomicae
Z Root Definition zygoma
zygomata
Modern Style
The examples given in Tables 4.4 and 4.5 depict traditional usage. However, everything is subject to change. For example, we see with increasing frequency in modern writings that singular word endings of “a” are pluralized by adding the common “s” rather than the traditional “ae” (eg, antennas rather than antennae). In singular words ending in “ma,” we see editors also using the common “s” rather than the traditional “mata” (eg, adenoma rather than adenomata). In the singular words ending in “ad,” use of the common “s” is replacing the traditional “ades” (eg, gonads rather than gonades). Whichever form is used, consistency is the important consideration. Some examples are shown below:Traditional Traditional Modern Singular Plural Plural antenna antennae antennas bursa bursae bursas fossa fossae fossas lamina laminae laminas adenoma adenomata adenomas enema enemata enemas fibroma fibromata fibromas gonad gonades gonads Monad monades monads
COMMON ANATOMICAL TERMSTerms of position, direction, and location are commonly used in reference to body parts. Following are some examples.
Terms of Patient PositionAdams position. Standing with the heels together, the knees locked, and the spine fully flexed forward.
Anatomical position. Standing erect with the arms at the sides and the palms of the hands facing forward. The anatomical position is the position of reference when terms of direction and location are used.
Antalgic position. Any physical attitude assumed to gain some relief of pain.
Knee-chest position. Resting on the knees and upper chest (also called the genupectoral position).
Knee-elbow position. Resting on the knees and elbows (also called the genucubital position).
Lateral recumbent position. Lying on either the right or left side, with one or both hips and elbows flexed.
Lithotomy position. Lying in a supine position with the hips and knees flexed at right angles, with the feet usually supported by stirrups (also called the dorsosacral position); a variant of Simon’s position.
Physiologic position. Standing in the habitual posture.
Prone position. Lying face down.
Simon’s position. Lying supine with the hips slightly raised and flexed, the knees flexed, and the thighs widely separated.
Sims’ position. Lying in a lateral recumbent position with one arm behind the back; the thighs are flexed, the upper more than the lower (also called the semiprone or English position).
Supine position. Lying on the back, face up (also called the dorsal position).
Terms of Direction and LocationAnterior. Toward or nearer the front or belly side of the body; ventral.
Caudad. Toward the feet.Cephalad. Toward the head or cranial vertex.
Contralateral. On the opposite side.
Distal. Away from the point of reference or origin.
Dorsal. Posterior.
Inferior. Situated or directed below; caudad.
Ipsilateral. On the same side (homolateral).
Lateral. Away or farther from the median or midsagittal plane, right or left of the midline; toward the side.
Medial. Toward or nearer the midline, median, or midsagittal plane.
Palmar. Referring to the palm or volar surface of the hand.
Plantar. Referring to the sole or volar surface of the foot.
Posterior. Toward or nearer the back or backside of the body; dorsal.
Proximal. Near the point of reference or origin.
Superior. Situated or directed above; cephalad.
Ventral. Anterior.
Volar. Referring to the palm of the hand or sole of the foot.
The Planes of the Body in Biodynamics
Motion occurs in a plane. The question arises: What is a plane? Simply put, a plane is any real or theoretical flat surface containing all the straight lines required to connect any two points on it.
Many chiropractic hypotheses derive from the science of biomechanics, and many basic considerations in biomechanics involve time, mass, center of mass, movement, force, and gravity which operate according to the laws of physics. However, while numerous parameters of movement are interrelated, no one factor can completely describe movement by itself.
Because a mechanical force, either traumatic or therapeutic, may act along a single line in a single plane or in any direction in space, this factor must be considered in any reference system. Such a reference system is necessary if we are to communicate effectively with each other about joint position and motion. Thus, the following sections will review pertinent terms and principles that will enhance your communicative skills as well as deepen your understanding of spinal dynamics.
STRUCTURAL MOTION
Figure 4.1 The planes of the body as related to the line of gravity. The X (frontal) axis passes from side to side (horizontally) and perpendicular to the sagittal plane. The Y (vertical) axis passes perpendicular to the transverse plane and the ground. The Z (sagittal) axis is perpendicular to the frontal plane, passing horizontally from front to back.
From a clinical viewpoint, structural motion can be defined as any body part’s relative change of place or position in space within a timeframe and about some other object in space. Thus, motion may be determined and illustrated by knowing and showing its position before and after an interval of time. While linear motion is readily demonstrated in the body as a whole as it moves in a straight line, most joint motions are combinations of translation and angular movement that are more often than not diagonal rather than parallel to the cardinal planes of the body. For example, a vertebra cannot move in the anterior-posterior (A-P) plane because its articulating facets are slanted obliquely. Besides muscle force, joint motion is governed by factors of movement freedom, axes of movement, and range of motion.
The force of gravity is always directed toward the earth’s center. Thus, the gravity lines of action and direction are constants. In the upright “rigid” body posture, the gravitational force on the entire body can be considered a single vector through the center of mass that represents the sum of many parallel positive and negative coordinates (See Figure 4.1).
DESCRIBING POSITIONS IN SPACE
In a two-dimensional reference system, the plane is simply divided into four quadrants by a perpendicular vertical ordinate line (Y axis) and a horizontal abscissa line (X axis). A third axis (usually labeled Z) can be used to locate points in three dimensions. The Z axis crosses the origin and is perpendicular to planes X and Y.
There are several reference systems. This particular system is the Cartesian coordinate system in which: (1) flexion/extension rotation is rotation about the X axis, (2) axial rotation is rotation about the Y axis, and (3) lateral flexion rotation is rotation about the Z axis. All Z points in front of the X-Y plane are called positive, while those behind are called negative (See Figure 4.2). By using X, Y, and Z coordinates, any point in space can be located and depicted. However, a minimum of six coordinates is necessary to specify the position of a rigid body (eg, a vertebra).
Figure 4.2 Left, positive and negative X, Y, and Z axes.
Right, system of coordinates pertinent to the mechanical axis of the hip.
In biomechanics, the body’s reference origin is at the body’s center of mass. When this point is known, gross body space can be visualized as in the sagittal (right-left) Y-Z plane, frontal or coronal (anterior-posterior) X-Y plane, or horizontal or transverse (superior-inferior) X-Z plane. With such a reference system, movement of any body segment in these planes can be described by placing a coordinate system at the axis of a joint and projecting the action lines of the muscles involved.
AXES
An axis is a straight line around which an object rotates, a line serving to orient a space or object (about which the object is symmetrical), or a reference line in a system of coordinates. Most body movements are rotations about joint axes and are rarely confined to a simple arc. Such motions vary to compensate for muscle/joint restrictions, bones twisting about their axes, and the transfer of power from one set of muscles to another within the range of movement. The joint surfaces of spinal joints are usually convexo-concave in design; ie, the convex (rounded) surface is larger than the concave (hollowed) surface. This relationship is exaggerated in all ball-and-socket joints.
If the anatomical position is used as a reference point, joint movements occur in a definite plane and around a definite axis. Flexion, extension, and hyperextension are movements in the sagittal plane about a frontal axis. Abduction and adduction are movements in the frontal plane about a sagittal axis. Rotation, pronation, and supination are movements in the transverse plane about a vertical axis. Circumduction is movement in both the sagittal and frontal planes.
LINEAR AND CIRCULAR MOTION
The two basic types of body motions are linear movement and circular movement.
Linear motion occurs when the body as a whole or one of its parts is moved as a whole from one place to another in a straight line. An example of linear (sliding, gliding, translation) movement without any circular motion is long axis distraction of a finger joint.
Circular movement (angular, rotational) occurs when the body or a part is moved around the arc of a circle. An example of circular motion is seen between the long bones of the extremities and in the spinal column. Circular movements occur in definite planes and around definite axes (centers of rotation). They comprise an important diagnostic viewpoint in musculoskeletal disorders, and, as previously described, each of these three axes of rotation is perpendicular to the plane in which motion occurs.
DEGREES OF JOINT MOVEMENT FREEDOM
The body is composed of many uniaxial, biaxial, and multiaxial joints.
Joints with one axis have one degree of freedom to move in one plane such as pivot and hinge joints. Joints with two axes have two degrees of freedom to move in two different planes, and joints with three axes have three degrees of freedom to move in all three planes (eg, ball-and-socket joints). Thus, the potential motion in which an object (eg, a body part) may translate to and fro along a straight course or rotate one way or another about a particular axis equals one degree of freedom.
The degrees of freedom of a fingertip about the trunk, for example, are the sum of the degrees of freedom of all the joints from the distal phalanges to the shoulder girdle. While the distal phalanges have only one degree of freedom (flexion-extension), the entire upper extremity has 17 degrees totally. This summation process is an example of an open kinematic chain.
COMBINED MOVEMENTS
Simple translatory motions of a body part invariably involve movements of more than one joint. This requires reciprocating actions of three or more segments at two or more joints if parallel lines are to be followed. For example, a fingertip cannot be made to follow the straight edge of a ruler placed in front when the wrist, elbow, and shoulder joints are locked. The fingertip then must follow an arc, not a straight line. Thus, human motion can be described as translation that gains major contributions from linear, angular, and curvilinear movements. The terms general or three-dimensional body motion infer that a body part may move in any direction by combining multidirectional translation and multiaxial rotation.
PLANE MOTION
Any motion in which all coordinates of a rigid body move parallel to a fixed point is called plane motion. Such motion has three degrees of freedom (ranges of motions); viz, (1) moving toward the anterior or posterior, (2) laterally moving toward the right or left, and (3) spinning in one direction or the other. In other words, plane motion has two translatory degrees of motion along two mutually perpendicular axes and one rotational degree of motion around an axis perpendicular to the translatory axes. Thus, when a person flexes his spine forward, the vertebrae flex and rotate in a single plane about an axis perpendicular to the sagittal plane. In such plane motion, various points on a particular vertebra will always move in parallel planes.
THE INSTANTANEOUS AXIS OF ROTATION
Plane motion is described by the position of its instantaneous axis of rotation and the motion’s rotational magnitude about this axis. In the above example of spinal flexion, for instance, as a vertebra moves in a plane, there is a point at every instant of motion somewhere within or without the body that does not move. If a line is drawn from that point so it perpendicularly meets the line of motion, the point of intersection is called the instantaneous axis of rotation for that motion at that particular time. Most joint motions are largely rotational movements, but the axis of motion may change its location and/or its orientation during a complete range of motion.
OUT-OF-PLANE MOTION
As contrasted to plane motion, out-of-plane motion is a type of general body motion with three degrees of freedom: two rotations about mutually perpendicular axes and translation perpendicular to the plane formed by the axes. Thus, in out-of-plane motion, the body as a whole or a segment can move more than in a single plane. For example, if a person bends laterally, a midthoracic vertebral body translates from the sagittal plane toward the horizontal plane. This is not plane motion because various points on the vertebra do not move in parallel planes.
Terms of Motion
The mental picture of the spine being a straight, vertical, static structure is inaccurate. It is a living, dynamic, segmented organ that is in constant motion during locomotion and work, and even with every breath taken during rest. As with most organs of the body during day or night, work or rest, the spine never rests —it is in constant motion, constantly dynamic.
The terms previously described in this chapter concerning position, direction, and location generally refer to static positions; ie, when the body is apparently still. Thus, additional terms are necessary to describe actions involved when body parts (eg, joint parts) move from one place in space to another such as during bending, lifting, walking, and running. Common examples are described below.Motion. Movement refers to a continuous change (displacement) of position. Coupling. Coupling is a motion of translation or rotation occurring along or about an axis as an object (eg, a vertebra) moves about another axis. Kinetics. Kinetics is the study of the rate of change of a specific factor in the body that disregards the cause of the motion; ie, the study of the relationship between a force acting on a body or body segment and the changes produced in body motion. Kinetic actions are expressed in amounts per units of time.
Kinematics. Kinematics is the complex study of motions of body parts and forces causing motion (with emphasis on displacement, acceleration, and velocity) that is mainly the result of muscle activity. Flexion and Extension. Generally, when the joint angle becomes smaller than when in the anatomical position, it is in flexion. For example, when the elbow is bent, it is flexed. The opposite of flexion is extension. Thus, when the elbow is straight, it is extended. Most joints can flex and extend. When motion exceeds the normal range, it is called hyperflexion or hyperextension; eg, as in instability of the elbow or knee.
Abduction and Adduction. When a part is farther away from the midline than it is in the anatomical (zero) position, it is in abduction. The opposite of abduction is adduction. Abduction and adduction occur at the shoulder, metacarpophalangeal, hip, and metatarsophalangeal joints.
Elevation and Depression. Raising a part from its normal (zero) position is called elevation. Depression means to lower a part from its normal position. Good examples of both show in the shoulder.
Circumduction. Movement of a bone circumscribing a cone such as at the shoulder or hip is called circumduction. Such motions usually comprise at least flexion, extension, abduction, and adduction.
Rotation. If a bone of a joint is capable of angular motion or turning on its longitudinal axis (spinning), the motion is called rotation. The motion of turning an anterior surface of a part toward the midline of the body is called inward or internal rotation. The motion of turning out is called outward or external rotation. The axis may be located outside or inside the rotating body. The classic example of internal-external rotation is at the shoulder.
Pronation. The word pronation refers to the act of assuming the prone position or the state or condition of being prone. When applied to the hand, it refers to the act of turning the hand backward, posteriorly, or downward by medial rotation of the forearm. When applied to the ankle or foot, it refers to a combination of eversion and abduction movements taking place in the tarsal and metatarsal joints that result in lowering the medial margin of the foot and thus the longitudinal arch. Supination. Supination is the opposite of pronation. It is the act of turning the palm forward or upward or of raising the medial margin or longitudinal arch of the foot. Pronation and supination movements are seen at the forearm (rotation of forearm between the wrist and elbow, palm turning up or down, respectively) and in the foot. However, inversion and eversion are better terms to use for actions of the foot than pronation and supination.
Dorsiflexion and Plantar Flexion. Backward flexion or bending such as of the hand or foot is called dorsiflexion; movement toward the dorsal surface. Plantar flexion or palmar flexion is the opposite of dorsiflexion: movement toward the plantar surface or palm. In the hand or foot, the midline is an arbitrary line drawn through the middle finger or toe. Dorsiflexion movements are seen at the ankle and wrist, toes and fingers.
Inversion and Eversion. A turning inward, inside out, or other reversal of the normal relation of a part is called inversion. Inversion is a type of adduction of the foot where the plantar surface is turned inward relative to the leg. Eversion is the opposite of inversion, referring to a turning outward of a part. Eversion of the foot means to turn the plantar surface outward in relation to the leg.
Translation. Linear motion that occurs when all parts of an object at a given time have the same direction of motion about a fixed point is called translation. This commonly occurs in a train moving along a track, the body moving as a whole during gait, or a facet that glides or slips across a relatively fixed surface. Translation is measured in millimeters.
Degrees of Freedom. Vertebrae have six degrees of freedom (ranges of motions); ie, translation along and rotation about each of three orthogonal axes. Any motion in which an object may translate back and forth along a straight course or rotate one way or another about a particular axis equals one degree of freedom. For example, joints with one axis have one degree of freedom to move in one plane (eg, pivot and hinge joints). Joints with two axes have two degrees of freedom to move in different planes, and joints with three axes have three degrees of freedom to move in all planes (eg, ball-and-socket joints).
Range of Motion (ROM). ROM refers to the difference between two points of physiologic extremes of motion. Rotation is measured in degrees. A vertebra has six degrees of freedom as it moves in three-dimensional space; eg, translations along and rotations about each of the three cardinal axes (X, Y, and Z). If passive distraction is considered a motion, seven degrees of freedom exist.
Instantaneous Axis of Rotation (IAR). The IAR is that fixed point which does not move but about which rotation occurs. It can exist inside or outside the object moving and is subject to change at any given instant.
Closed Kinematic System. This phrase refers to a series of body links or a chain of joints in which segments are interdependent on each other for certain movements so each joint can function properly in a coordinated movement; eg, the movement of the first costotransverse joint necessary for the cervical spine to extend and laterally flex.
