Body Movement Terms Anatomy | Body Planes of Motion | Synovial Joint Movement Terminology

Summary

In this anatomy lesson, Ben from registerednessrn.com covers essential body movement terms at synovial joints, crucial for healthcare professionals. The video discusses four major movement categories: gliding, angular (flexion/extension, abduction/adduction), rotational, and special movements. Examples include wrist and ankle movements, shoulder and hip rotations, and unique thumb actions like opposition and reposition. These terms are vital for patient assessment and documentation in medical fields.

Takeaways

• 🔍 There are four major categories of movements at synovial joints: gliding, angular, rotational, and special movements.
• 📍 Gliding movements occur when bones move over each other in a linear direction without significant rotation, like waving your hand side to side.
• 🔺 Angular movements include flexion and extension, which decrease or increase the angle between two structures, respectively.
• 🤲 Rotational movements involve bones moving around a central axis, like the head turning from side to side.
• 🤸‍♂️ Special movements are unique and don't fit into other categories, such as supination and pronation of the forearm and dorsiflexion and plantar flexion of the foot.
• 👐 Abduction and adduction are angular movements that occur in the frontal plane, moving structures away from or towards the body's midline.
• 🔄 Circumduction is a complex movement that combines flexion, abduction, extension, and adduction to create a circular motion.
• 👣 Inversion and eversion are special movements that turn the sole of the foot toward or away from the body's midline.
• 🦴 Hyperextension refers to movements that exceed the normal range of motion for a joint, sometimes causing confusion in terminology.
• 🤗 Opposition and reposition are special movements of the thumb, allowing it to touch the tips of other fingers and then return to the original position.

Q & A

What are the four major categories of movements that can occur at synovial joints?

The four major categories of movements at synovial joints are gliding movements, angular movements, rotational movements, and special movements.

What is gliding movement and where does it primarily occur?

Gliding movement occurs when the surfaces of bones move over one another in a linear direction without significant rotary or angular movement. It primarily takes place in the carpels of the wrist and the tarsals of the foot.

Can you explain the difference between flexion and extension?

Flexion decreases the angle between two structures as they bend or move closer together, while extension increases the angle as they straighten and move apart.

How does abduction differ from adduction?

Abduction is the movement of a structure away from a midline reference point, whereas adduction occurs as the structure is moved back toward the midline reference point.

What is circumduction and how is it performed?

Circumduction is an angular body movement that blends flexion, abduction, extension, and adduction to create a circular or conical movement. It is performed by combining these movements in a smooth sequence to form a cone or circle at a joint.

What is rotation in the context of body movements?

Rotation is a body movement term that describes a bone moving around a central axis, similar to a screw turning to either the right or the left.

What are supination and pronation, and how do they relate to the forearm?

Supination and pronation are special movements involving the rotation of the forearm. Supination is the rotation of the radial bone laterally (away from the body's midline), while pronation is the rotation medially (toward the body's midline).

Define dorsiflexion and plantar flexion in relation to the foot and ankle.

Dorsiflexion is the movement where the back or upper side of the foot moves toward the shin, decreasing the angle between the foot and the leg. Plantar flexion is when the sole of the foot moves toward the calf, decreasing the angle and pointing the toes away from the body.

How do inversion and eversion of the foot differ?

Inversion is when the bottom of the foot turns so that it faces toward the body's midline, while eversion is the opposite motion where the bottom of the foot turns away from the body's midline.

What are the special movements of the thumb called opposition and reposition?

Opposition of the thumb is when the tip of the thumb meets and opposes the tip of another finger from the same hand. Reposition is the return of the thumb and finger to their original position after opposition.

Outlines

00:00

🔍 Overview of Synovial Joint Movements

Ben from registerednessrn.com introduces an anatomy lesson focusing on major body movement terms associated with synovial joints. He outlines four main categories of movements: gliding, angular, rotational, and special movements. Gliding movements are explained as linear bone surface movements without significant rotation, exemplified by waving the hand. Key joints where gliding occurs include the carpels of the wrist and the tarsals of the foot, as well as other plane joints like the sacroiliac joint and the acromioclavicular joint. Ben also covers angular movements, starting with flexion and extension, which involve decreasing and increasing the angle between two structures, respectively. Examples include elbow flexion and extension, shoulder and wrist movements, and even finger and thumb movements, all of which are crucial for healthcare professionals to understand when documenting or assessing patients.

05:01

💪 Angular Movements: Flexion, Extension, and Hyperextension

The paragraph delves deeper into angular movements, particularly flexion and extension, which occur in the sagittal plane. Flexion decreases the angle between body parts, as seen in actions like bending the elbow, while extension increases it, as in straightening the arm. Ben also discusses hyperextension, where a body part moves beyond the normal anatomical position. He notes the variability in defining hyperextension among anatomists but advises students to follow their professor's definition for academic purposes. The paragraph also introduces lateral flexion and extension of the vertebral column, emphasizing the importance of understanding these movements for healthcare documentation and patient assessment.

10:02

🚶‍♂️ Abduction and Adduction: Movements in the Frontal Plane

This section explains abduction and adduction, which primarily occur in the frontal or coronal plane. Abduction is the movement away from the body's midline, akin to someone being 'taken away', while adduction brings the structure back toward the midline. Examples include arm abduction and adduction, finger movements, and even wrist actions described as radial and ulnar deviation. The thumb, having a different orientation, performs abduction and adduction within the sagittal plane. Ben also discusses the abduction and adduction of the lower limbs, toes, and provides a clear demonstration of circumduction, a complex movement blending flexion, abduction, extension, and adduction to form a circular motion. The mnemonic 'FABlA' is introduced to help remember the order of movements in circumduction.

15:04

🔄 Rotation and Special Movements of the Body

The focus shifts to rotation, a movement where a bone turns around a central axis, likened to a screw turning. Rotation occurs in the head, vertebral column, and ball and socket joints of the limbs. Ben illustrates how the head and trunk can rotate laterally and return to the anatomical position through medial rotation. He also details the external and internal rotations of the shoulder and hip joints. Special movements like supination and pronation of the forearm, which involve the radius rotating around the ulna, are explained. Supination turns the palm anteriorly, while pronation turns it posteriorly. A mnemonic is provided to remember these movements: 'Pronate to pick up produce, supinate to eat it for supper.'

20:05

👣 Special Movements of the Foot, Ankle, and Mandible

The final paragraph covers special movements like dorsiflexion and plantar flexion of the foot and ankle, which involve the upper and lower side of the foot moving towards the shin or calf, respectively. Inversion and eversion are movements that turn the sole of the foot toward or away from the body's midline. Elevation and depression describe upward and downward movements, commonly associated with the mandible and scapulae. Protraction and retraction involve the scapulae moving forward or backward, while protrusion and retrusion describe the anterior and posterior movement of the mandible. Excursion is the side-to-side movement of the mandible. Opposition and reposition of the thumb are also discussed, highlighting the thumb's unique ability to touch the tips of other fingers due to the saddle joint at the thumb's base. The video concludes with an invitation to take a quiz on the website and explore more anatomy videos.

Keywords

💡Synovial Joints

Synovial joints are a type of joint found in the body that are characterized by their ability to allow for a wide range of movement. They are surrounded by a joint capsule filled with synovial fluid, which lubricates the joint and reduces friction. In the video, the instructor discusses how various movements occur at these joints, highlighting their importance in human anatomy and movement.

💡Gliding Movements

Gliding movements refer to the sliding motion of bones over one another in a linear direction without significant rotation. This type of movement is exemplified in the video by the action of waving one's hand from left to right. The instructor mentions that gliding primarily occurs in the carpels of the wrist and the tarsals of the foot, emphasizing the role of these joints in facilitating such movements.

💡Angular Movements

Angular movements involve changes in the angle between two structures, either decreasing or increasing it. The video explains two specific angular movements: flexion, which decreases the angle and brings structures closer, and extension, which increases the angle and moves structures apart. Examples given include elbow flexion and extension, which are directly related to the video's theme of understanding joint movements.

💡Rotational Movements

Rotational movements describe the action of a bone spinning around a central axis. The video uses the analogy of a screw turning to illustrate this concept. Rotational movements are highlighted in the context of the head, vertebral column, and ball and socket joints, which are crucial for the range of motion in these areas.

💡Special Movements

Special movements are unique types of movements that don't fit into the other categories. The video discusses several of these, including supination and pronation of the forearm, and dorsiflexion and plantar flexion of the foot and ankle. These movements are integral to the complex actions of daily life, such as grasping objects or walking.

💡Flexion

Flexion is an angular movement that decreases the angle between two bones or structures, causing them to bend or move closer together. The video provides examples such as wrist flexion, where the palm moves closer to the anterior surface of the forearm, demonstrating the concept's relevance to joint function and movement.

💡Extension

Extension is the opposite of flexion, where the angle between two bones or structures increases as they straighten and move apart. The video uses examples like elbow extension to clarify this movement, which is vital for understanding how joints contribute to the overall mobility of the body.

💡Abduction

Abduction is a movement where a body part is moved away from the midline of the body. The video explains this concept using arm abduction as an example, where the arms move away from the body's midline, illustrating the importance of this movement in the context of body mechanics and spatial awareness.

💡Adduction

Adduction is the movement of a body part back toward the midline of the body, opposite to abduction. The video uses finger adduction as an example, where the fingers are brought back towards the midline of the hand, highlighting the concept's significance in the context of fine motor skills and hand function.

💡Circumduction

Circumduction is a complex movement that combines elements of flexion, abduction, extension, and adduction to create a circular or conical motion at a joint. The video demonstrates this by moving the shoulder joint through these combined movements, forming a cone shape, which is a key concept in understanding the full range of motion possible at certain joints.

Highlights

Introduction to major body movement terms at synovial joints

Definition and example of gliding movement

Examples of joints that allow gliding movement

Explanation of angular movements: flexion and extension

Demonstration of elbow and shoulder flexion and extension

Flexion and extension of the wrist, fingers, and thumb

Hip and knee flexion and extension movements

Flexion and extension of the vertebral column and neck

Clarification on hyperextension and its definitions

Abduction and adduction movements in the frontal plane

Examples of arm, finger, and wrist abduction and adduction

Abduction and adduction of the thigh and toes

Introduction to circumduction and its definition

Demonstration of shoulder circumduction

Mnemonic 'FAbia' for remembering circumduction movements

Definition and examples of rotation movement

Special movements: supination and pronation of the forearm

Mnemonic for remembering supination and pronation

Special movements: dorsiflexion and plantar flexion of the foot

Special movements: inversion and eversion of the foot

Special movements: elevation and depression of the mandible and scapulae

Special movements: protraction and retraction of the scapulae

Special movements: protrusion, retrusion, and excursion of the mandible

Special movements: opposition and reposition of the thumb

Conclusion and invitation to take a comprehensive quiz on the website

Transcripts

hey everyone this is ben with

registerednessrn.com and in this anatomy

lesson

i'm going to cover all the major body

movement terms that can occur at the

synovial joints

and if you happen to go into a

healthcare profession you'll probably be

using some of these terms during

documentation

or assessing your patients and so on

there are four

major categories of movements that can

occur at the synovial joints

you have gliding movements angular

movements rotational movements

and special movements let's start with

gliding

so what is gliding gliding occurs when

the surfaces of bones

move over one another in a linear

direction

without significant rotary or angular

movement

the most common example of gliding is

just simply taking your hand

and moving it from left to right in a

waving motion like this

and that can help you remember that the

gliding joint movements primarily take

place in the carpels of the wrist

and the tarsals of the foot however

gliding can also occur

in the other plane joints of the body

and a simple way to remember which

joints allow gliding

a plane joint think of airplane gliding

through the air

so the plane joints are going to allow

gliding and some examples of joints that

do this are the sacroiliac joint of the

pelvis

the acromioclavicular joint of the

shoulder the femoral patellar joint

the tibiofibular joint the vertebral

costal and sternocostal joints of the

ribs

as well as the intervertebral joints of

the spine

now let's talk about the angular

movements and i'll begin with

flexion and extension and i find

personally that it really helps to think

in terms of angles because

flexion is going to decrease the angle

between two structures

as they bend or move closer together

whereas extension is going to

increase the angle between those

structures as they straighten and move

apart

so let's take a look at some examples of

flexion and extension

elbow flexion also called forearm

flexion

occurs when the angle between the

forearm and arm

decreases allowing the ulna of the

forearm to move closer

to the humerus bone of the arm in

contrast elbow extension

also called forearm extension occurs

when the forearm moves away from the arm

increasing the angle between those bones

shoulder flexion

also called arm flexion occurs when the

angle between the humerus of the arm

and the scapula decreases in contrast

shoulder extension also known as arm

extension

occurs when the angle between the

humerus of the arm and the scapula

increases causing the arm to move

posteriorly

and the joint here allows posterior

movement past the anatomical position

flexion of the wrist also called hand

flexion

occurs when the angle between the palm

of the hand and the anterior surface of

the forearm

decreases while extension of the wrist

or hand extension

is moving the palm of the hand away from

the anterior surface of the forearm

hence the angle increases as it

continues to move beyond the anatomical

position finger flexion occurs when the

angle between the anterior surface of

the fingers

and the palm decreases and when the

angle between the fingers and the palm

increases finger extension occurs

flexion and extension can also occur

within the

interphalangeal joints now as you can

tell up to this point

most of the movements with flexion and

extension are going to occur

within that sagittal plane or parallel

to the sagittal plane

however with the thumb it's a little bit

different thumb flexion is going to have

the thumb moving toward the pinky

kind of parallel to the palm within that

frontal plane and some

extension is going to have the thumb

moving away from the pinky and if you

think of your palm as a windshield

and your thumb is a windshield wiper

it's going to kind of go back and forth

in that kind of a motion

flexion and extension can also occur at

the interphalangeal joint of the thumb

next we have hip flexion also called

thigh flexion

which occurs when the angle between the

femur of the thigh

and the hip bone decreases as the thigh

moves anteriorly or forward

hip extension or thigh extension occurs

when the angle between the femur and the

hip bone

increases as the hip joint straightens

and just like the shoulder joint this

joint also allows movement past the

anatomical position

knee flexion also called leg flexion

occurs when the tibia bone moves

toward the femur causing the angle to

decrease between those two structures

knee extension or you could say leg

extension occurs as the angle between

those leg bones

increases causing the leg to straighten

and just like the fingers

toe flexion and extension can also occur

vertebral column flexion

or spine flexion occurs when the angle

between the trunk

and the hip joint decreases and spine

extension occurs as the spine

straightens

neck flexion occurs as the angle between

the head and the trunk of the body

decreases

whereas neck extension occurs as the

head moves away from the trunk of the

body

and the neck is another one of those

structures that can continue posteriorly

beyond the anatomical position

the vertebral column can also experience

flexion within that frontal plane

for example if you bend the spine to the

left or to the right

that's called lateral flexion and

movement

back toward the anatomical position is

called

lateral extension and then finally i

want to talk a little bit about

hyperextension because whenever a

structure moves beyond a certain point

anatomist will refer to that as hyper

extension

now what can get a little tricky with

this is that anatomist will sometimes

define hyperextension differently

for example some anatomists will say

that when the arm neck

wrist or leg moves past the normal

anatomical position in a posterior

motion

it actually becomes hyperextension and

not just extension

whereas other anatomists will only

consider these movements hyperextension

if the movement exceeds the normal range

of motion permitted by that joint

obviously for test taking purposes

you'll want to do whatever your anatomy

professor says

but i just wanted to give you a heads up

about that now unlike flexion and

extension body movements which mostly

take place within the sagittal plane or

parallel to the sagittal plane

abduction and adduction movements are

mostly going to take place within the

frontal or

coronal plane however the thumb is one

exception and i'll demonstrate abduction

and adduction of thumb

later in this video so what is abduction

abduction is the movement of a structure

away from a midline reference point

and let the name help you out what does

abduct mean

when you hear on the news that a man was

abducted you know it means that someone

took them away

and that's exactly what's going on with

this movement the structure is being

moved away from the midline

reference point now what is adduction

adduction occurs as the structure is

added back toward the midline reference

point

so let's take a look at some examples of

abduction and

adduction on the body during arm

abduction

the arms move away from the body's

midline during arm

adduction you add them right back toward

the midline

finger abduction occurs when the fingers

move away from the midline of the hand

whereas finger adduction occurs when you

add them back toward the hand's midline

when the middle finger which serves as

the midline point of the hand

deviates away from the body in the

anatomical position

it's called lateral abduction and when

it deviates toward the body

it's considered medial abduction and as

i mentioned earlier the thumb is going

to operate a little bit differently

because it has a different orientation

than the other fingers

abduction of the thumb has it moving

within the sagittal plane in an anterior

motion

and adduction of the thumb has it added

back to the hand

when determining abduction and adduction

of the wrist

i find that it helps to stand in the

anatomical position

abduction of the wrist has it moving

away from the body's midline

in the same direction as arm abduction

adduction of the wrist has it going in

the opposite direction

toward the body's midline these

movements are also referred to as radial

deviation

and ulnar deviation remember the radius

is on the thumb side which is where you

check the radial pulse

so radial deviation is the movement

toward the radial side

and ulnar deviation is toward the other

side during thigh

abduction the lower limb moves away from

the body's midline

and during adduction of the thigh you

add the lower limb

right back toward the body's midline

when the toes move away from the midline

of the foot

and spread apart abduction occurs and

adduction of the toes adds them right

back together

and just like with the hand the foot is

also going to have its own midline

reference point which is the second

toe and whenever that second toe

deviates

away from the body's overall midline

then that's called lateral abduction

and whenever the second toe moves toward

the body's midline then that's called

medial abduction

and finally i'll demonstrate

circumduction which is an angular

body movement term that blends the

motions of flexion

abduction extension and adduction to

create a circular or

conical movement now the word

circumduction starts with the exact same

letters as the word

circle so that will tip you off that

this movement is going to create that

circular or conical movement at a joint

because circumduction utilizes four

different movements i like to do it in

slow motion so i can see how those four

movements combine to create that

circular effect

looking at the shoulder joint i'll begin

with arm flexion

then arm abduction next is arm extension

followed by arm adduction and when you

combine those movements into a smooth

motion you can see how it forms a cone

or circle this sort of feels like it

could be the next big dance move

[Music]

and if you have trouble remembering the

specific order of these movements you

can remember the mnemonic

fabia which stands for flexion abduction

extension and adduction now you can also

reverse that order and do it the other

way

however the movements are going to have

to alternate in a similar succession

in order to create that circular motion

now where does circumduction occur on

the body

well generally speaking it requires that

flexion

abduction extension and adduction so

it's going to occur at the joints of the

body that allow those specific movements

circumduction can occur at the hip joint

or thigh circumduction can occur at the

shoulder joint or

arm circumduction of the wrist or hand

can also occur

circumduction of the thumb can occur

circumduction of the fingers

circumduction of the ankle or foot you

have circumduction of the toes

and circumduction of the head now let's

talk about rotation

what is rotation rotation is a body

movement term that describes a bone

moving around a central

axis when i think of the rotation body

movement i like to picture a screw

turning to either the right or the left

as that is basically the same kind of

motion

that can occur in the body with this

movement rotation can occur at the head

vertebral column and the ball and socket

joints of the upper and lower limbs

so let's take a look at some of these

movements the head can rotate

laterally to either the left side or the

right side

thanks to a pivot joint between

vertebrae c1

and c2 now returning the head toward the

anatomical position

is going to be medial rotation of the

head the vertebral column can also

rotate

laterally to either the left or the

right

and returning the trunk toward the

anatomical position

is medial rotation of the trunk you spin

me right round baby right round

the ball and socket joint of the

shoulder allows the humerus of the arm

to rotate

laterally or away from the body's

midline

which is also called external rotation

it can also rotate medially or toward

the body's midline

which is also called internal rotation

the ball and socket joint of the hip

allows rotation of the thigh's femur

and just like with the humerus it can

rotate laterally or

away from the body's midline which is

also called external rotation

and it can also rotate medially or

toward the body's midline

creating an internal rotational movement

and one thing that you want to keep in

mind is whenever you're looking at the

rotation of the arm or the thigh

you're going to want to focus in on the

anterior surface of it

so the front of the arm or the front of

the thigh keep that as your focal point

and if it's moving toward the body's

midline you know it's going to be medial

rotation of those structures

or internal rotation and if it's moving

away from that you know it's

lateral or external rotation and finally

we have the last category of body

movement terms that don't fit into any

of the other categories

so these are called the special

movements first let's talk about

supination and pronation which are

special movements involving rotation

of the forearm your forearm consists of

two bones you have the

radius which is on the lateral side of

the forearm in the anatomical position

and you also have the ulna which is on

the medial side in the anatomical

position

during supination the distal end of

the radial bone is going to rotate

around the ulna

in a lateral direction now lateral

rotation is

away from the body's midline so this

motion is going to look like this

and i like to pay attention to the

thumbs because the thumb is on the same

side as the radius

hence when you check a radial pulse

you're checking

just below the thumb right here so when

you look at the thumbs and if you

imagine there's a midline going down my

body

like kind of in line with my necktie

watch the thumbs and as it's rotating

away

from the midline of the body this is

supination

in contrast pronation is the opposite

movement here

we're going to see the distal end of the

radial bone rotate over the ulna in a

medial direction

so medial means towards the midline of

the body so now we're going to see those

thumbs point

towards the body's midline some people

also like to look at the

orientation of the palms of the hand to

help them determine whether

supination or pronation is occurring so

if i put my arms down like this and you

look at the palms of my hands

supination is going to result in that

lateral rotation of the radial bone

which is going to

leave your palms facing forward or

anteriorly

and this might look familiar because

this is exactly

their orientation in the anatomical

position however if my elbow were flexed

about 90 degrees

now what's happened the palms are facing

up in contrast pronation is going to

have the palms facing the opposite

direction they are going to face

posteriorly or toward the back in the

anatomical position

or if my elbow reflects about 90 degrees

then pronation is going to have the

palms facing

down or inferiorly now let me give you a

really simple mnemonic to help you

remember these two movements

you see this girl right here at the

store she has to pronate

to pick up her produce so you have to

pronate to pick up your produce

and when you want to eat it for supper

you supinate and bring it to your mouth

or if you want to take a multivitamin

you have to pronate to poor

and you have to supinate to catch the

supplement next we have dorsiflexion

and plantar flexion which are special

movements involving the foot

and ankle joint now to help you

understand this movement let's break

down the words

dorsal refers to the back or upper side

of something

in my video on directional terms i use

the example of a dorsal fin of a dolphin

to help me remember that dorsal refers

to the back side or upper side of a

surface

your toenails for example are on the

dorsal side of the foot

in contrast plantar refers to the sole

or bottom of the foot if you've ever had

a plantar wart then you've had a wart

right there on the sole of your foot

and then flexion in anatomy just refers

to a movement that decreases the angle

between

two surfaces now let's put those words

together and you will totally understand

this movement

during dorsiflexion the back or upper

side of the foot

moves toward the shin decreasing the

angle between these two surfaces

leaving the toes pointing a little bit

closer to the head and yes i know i have

tan lines on my feet

don't judge when you try to walk on your

heels only

you dorsiflex the foot and in nurse

sarah's preeclampsia and eclampsia

review

she used dorsiflexion to assess for

ankle clonus

during plantar flexion the sole of the

foot

moves toward the calf decreasing the

angle between

those two surfaces leaving the toes

pointing away from the body

when you perform calf raises in the gym

or walk on your tippy toes

you plantar flex the foot now let's talk

about inversion and eversion

which are special body movements that

turn the soul

either toward the body's midline or away

from the body's midline

during inversion the bottom of the foot

turns so that it faces toward the body's

midline

inversion starts with the word in so

that's the dead giveaway that the soul

is going to be pointing

inwardly or medially during eversion

the opposite motion occurs the bottom of

the foot turns so that faces away from

the body's midline

laterally the word evert literally means

to turn

outward which is exactly what happens

during

eversion now let's talk about elevation

and depression

elevation refers to the movement of a

body part in a superior

direction or moving upward whenever you

walk into a hotel lobby

you have to get on the elevator to go up

right and we'd also say that a mountain

has a really high peak elevation

therefore the term elevation is pretty

self-explanatory it has a structure

moving

up or superiorly in contrast depression

refers to the movement of a body part

going downward or in an inferior

direction

when you are depressed you feel down in

the dumps right

therefore it's easy to remember that

depression has a body part moving

downward or inferiorly in anatomy

elevation and depression most commonly

describe movement of the mandible

or the scapulae within the frontal plane

when you move your mandible in a

downward direction

depression occurs and when you move your

mandible upward

elevation occurs similarly when you move

your scapulae

up elevation of the shoulder girdle

occurs

and when you move them back down

depression of the shoulder

girdle occurs next we have protraction

and retraction which are special body

movements that involve the scapulae

better known as your shoulder blades

protraction moves the scapula

forward or anteriorly and toward the

side of the body or laterally

in an anterolateral direction retraction

is the opposite movement

it's going to cause the shoulder blades

to move back or posteriorly

and more toward the body's midline or

immediately

in a movement known as a postero medial

movement now here's a really simple way

to remember this movement

when you reach back you retract

and then you punch to protract in fact

the serratus anterior muscles

assist with this movement and they even

call this muscle the boxer's muscle for

this very reason

next we have protrusion retrusion

and excursion which are special body

movement terms that refer to motion

going

anteriorly posteriorly or side to

side protrusion refers to the movement

of a structure in an

anterior or forward direction in fact

the word protrude means

projecting something forward and i like

to call protrusion the

kissing movement because it occurs when

you

pucker your lips like you're going to

give someone a kiss or when you stick

out your tongue

or moving the mandible or lower jaw

forward

now retrusion is the opposite of

protrusion

it refers to movement going in a

posterior or

backward direction putting your tongue

back in your mouth

moving the lips back or moving the

mandible back

are all examples of retrusion in anatomy

now some anatomists will refer to that

forward and backward motion of the

mandible as protraction and retraction

just like i discussed with the shoulder

blades in my last video

however some prefer to use protraction

and retraction only when describing the

shoulder blades because

it's a combined movement for example

protraction is an

anterolateral movement whereas

protrusion and retrusion are more

anterior and posterior movements and

then finally we have

excursion which is a side to side

movement

of the mandible now some of you might

remember a character named ernest

p wuerl which is that guy and all those

movies from

earnest goes to camp ernest goes to jail

ernest saves christmas etc

and if you've ever seen one of those

movies then you have definitely seen the

excursion movement because

anytime earnest would see something

gross he would go

and that's basically all excursion is

it's the movement of the lower jaw which

is your mandible

in either a left or right direction and

anatomists use directional terms

to specify the type of excursion for

example

when the lower jaw moves to either the

left or the right

away from the midline of the body they

simply call that

lateral excursion and when the mandible

moves closer to the center of the body

it's called medial excursion now let me

demonstrate

opposition and reposition which are

special movements involving the thumb

now the thumb articulates or forms a

joint with the trapezium bone of the

wrist

via a saddle joint a type of synovial

joint

featuring interlocking convex and

concave

surfaces and they call it a saddle joint

because

well it looks like a saddle saddle up

cowboy yeehaw

now thanks to this saddle joint the

thumb can perform various movements such

as

circumduction flexion and extension

abduction and adduction as well

as special movements called opposition

and reposition opposition of the thumb

occurs when the tip of the thumb

comes to meet and oppose the tip of

another finger

from the same hand now a super simple

way to remember

this movement is that you've probably

heard someone say that humans have

opposable thumbs

and we do and that's what this movement

opposition is all about it's about

taking the thumb

and moving it around so that it opposes

each of the digits or fingers by

touching the tip like that

also check this out whenever opposition

occurs the thumb moves and

meets the tip of one of the fingers and

when you look at the shape that results

it kind of makes the shape of a letter

o o for opposition with our opposable

thumbs now reposition is super simple

because it is the

opposite action of opposition during

reposition

the thumb and finger return to their

original position

okay that wraps up this compilation

video over the major body movement terms

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