A&P - Chapter 8: Movement

long cards...

Gliding movement

occurs in plane joints

• slight movement

angular movement

angle between bones changes

circular motion

rotation around an axis

flexion

angular movement

decreases angle between two bones

movement of a body part anterior to the coronal plane for the top half of the body

extension

angular movement

straightening movement that increases angle of two bones

movement of a body part posterior to the coronal plane for the top half of the body

hyperextension

angular movement

extension of joint beyond anatomical position

• can be normal or caused by injury

plantar flexion

angular

flexion of the foot

• movement of the foot toward plantar surface

  • EX: standing on toes

dorsiflexion

angular

flexion of the foot

• movement of the foot toward the shin

  • EX: walking on the heels

abduction

angular motion

movement away from the midline

• abducted by aliens

adduction

angular motion

movement toward the midline

rotation

circular motion

turning of structure around long axis

• EX: shaking head no

pronation

circular motion

rotation of the forearm

prone = facedown

• palm faces posteriorly in anatomical position

radius and ulna are crossed

supination

circular motion

rotation of the forearm

supine = faceup

• palms face anteriorly in relation to anatomical position

radius and ulna are parallel

circumduction

Combination of flexion, extension, and abduction and adduction

occurs at freely movable joints like the shoulder

circular motion

arm moves in an arc as if tracing the base of a cone

special movements

Movements unique to only one of two joints

elevation

special movement

moves the structure superiorly

• EX: shrugging shoulders

depression

special movement

move structure inferiorly

• EX: opening the mouth

protraction

special movement

Gliding motion that moves the structure in an anterior direction

• EX: jutting out the jaw

retraction

special movement

Gliding motion that moves the structure in a posterior direction

• EX: pulling the scapulae back toward the vertebral column

lateral excrusion

special movement

moving mandible either right or left of the midline

medial excrusion

special movement

moving the mandible back to the midline position

opposition

special movement

unique to the thumb

thumb + tio of finger on same hand are brought toward each other across the palm

reposition

special movement

returns thumb to neutral anatomical position

inversion

special movement

turns ankle so that the plantar surface of foot faces medially toward the opposite foot

• weight on the outside edge of the foot

  • rolling out

eversion

Turns the ankle so the plantar surface of the foot faces laterally

• weight is on the inside edge of the foot

  • rolling in

range of motion

describes amount of mobility that can be given

active range of motion

amount of movement that can be accomplished by contracting muscles that normally act across a joint

passive range of motion

amount of movement that can be accomplished when structures that meet at the joint are moved by an outside force

• Chad doing his PT and forcing a patient to flex their arm

passive for normal joints is greater than active

dislocation

caused by movement of joint beyond normal range of motion

AKA luxation

occurs when articulating surfaces of bone are moved out of proper alignment

results in damage to supporting ligaments + articular cartilage

subluxation

a partial dislocation

sprain

occurs when ligaments are damaged

degree can range from stretched to completely torn

• results in inflammation, swelling, and pain

what influences range of motion for a given joint

1. shape of articular surfaces of the bones forming the joint

2. amount and shape of cartilage covering those articular surfaces

3. strength + location of ligaments, tendons, and muscles associated with the joint

4. bulk of surrounding tissues like muscle and adipose tissue

5. amount of fluid in and around the joint

6. amount of pain in and around the joint

7. amount of use or disuse the joint has received over time

abnormalities that impact range of motion

1. damage to ligament associated with a joint can increase range of motion

2. torn piece of cartilage within a joint can limit its range of motion

3. nerve supply to a muscle is damaged —> muscle is weakened so the active range of motion may decrease but the joint passive range is unchanged

4. fluid buildup and/or pain in or around the joint can limit both active + passive ranges

• Occurs when soft tissue around joint develops edema following an injury

5. Disuse can decrease both active + passive

joints

AKA articulations

Named according to bones or portions of bones that join together

EX: temporomandibular joint is between temporal + mandible

three types of joints

1. fibrous

2. cartilaginous

3. synovial

*named according to the major CT type that holds bone together + the presence of a fluid-filled joint capsule

functional categories of joints

according to degree of motion

1. synarthroses

2. amphiarthrosis

3. diarthrosis

synarthroses

nonmoveable joint

• fibrous + cartilaginous joints

amphiarthrosis

slightly movaeble joints

• fibrous + cartilaginous joints

diarthrosis

freely moveable joint

• synovial joints

fibrous joints

connection between two bones that are held together by fibrous CT

• have no joint cavity + exhibit little or no movement

three subdivisions

1. sutures

2. syndesmoses

3. gomphoses

sutures

seams found only between the bones of the skull

• some sutures become completely immovable in older adults

• Few are smooth, and the opposing bones often interdigitate (interlocking finger-like processes)

  • Interdigitation adds stability

• margins of bones within sutures are sites of continuous intramembranous bone growth that eventually become ossified

• When a suture fully becomes ossified, it becomes a synostosis

  • results when two bones grow together across a joint to form a single bone

fontanels

membranous area on a suture in newborns

• soft part of the skull that is flexible for the birthing process + allows for growth of the head after birth

suture tissue between each bone

dense, regular collagenous CT

• periosteum on inner + outer surfaces of adjacent bones continues over the joint

• two layers of periosteum + dense fibrous CT in between for a sutural ligament

syndesmosis

a slightly movable type of fibrous joint

• Bones are farther apart than in a suture

• Two bones are joined by ligaments (sheets of CT - collagen = interosseous membrane)

  • some movement can occur because ligaments are flexible

    • occurs in the radioulnar syndesmosis that binds the radius + ulna together

• movement can occur in one direction but not other

gomphosis

specialized joints that consists of pegs that fit into sockets + held in place by fine bundles of regular collagenous CT

• only located between teeth + sockets of the mandible + maxillae

  • CT bundles between the teeth + sockets are periodontal ligaments

    • allows a slight amount of “give” to the teeth during mastication

      • allows realignment by braces

cartilaginous joints

Holds two bones together by a pad of cartilage

• exhibits little to no movement

two subdivisions based on the type of cartilage:

• synchondroses

  • hyaline cartilage

• symphyses

  • fibrocartilage

synchondrosis

consists of two bones joined by hyaline cartilage with little or no movement occuring

• most are temporary

  • EX: epiphyseal plate in growing bones

    • synchondrosis is converted to a synostosis as bone replaces existing cartilage

• synchondrosis can be converted to synovial joints

  • EX: costochondral joints located between the ribs + costal cartilages

    • The change occurs because movement occurs between the ribs/costal cartilage and the sternum

      • EX: breathing

symphysis

consists of two bones joined by a pad of fibrocartilage

• EX: intervertebral disks, junction between the manubrium + body of the sternum, pubic symphysis

• the fibrocartilage is meant to withstand a lot of force and absorb shock

  • made out of a lot of organized cartilage

synovial joints

• typically unite bones of appendicular skeleton

• covered in a thin layer of hyaline cartilage (articular cartilage)

  • provides a smooth surface where bones meet

• The joint capsule that surrounds the joint has two layers

  • fibrous capsule

  • synovial membrane

• only blood supply and nerve supply to the synovial membrane

how does articular cartilage receive nourishment

BV that form a vascular circle at peripheral margin of cartilage but do not penetrate the cartilage or enter joint cavity

• nutrients and O2 must diffuse from surrounding vessels into cartilage due to lack of innervation

may receive nutrients from underlying spongy bone + synovial fluid covering the cartilage

sensory nerves of joints

• enters fibrous capsule + synovial membrane (but less)

  • supplies brain with information about pain + sends information about joint position + degree of movement

  • does not enter cartilage or joint cavity

joint cavity

• the space around the articular surfaces of bones in a synovial joint

  • filled with synovial fluid

    • includes hyaluronic acid which makes it slippery which prevents friction

    • includes proteins + fats

  • surrounded by joint capsule

    • helps bones together while still allowing movement

  • has two layers: fibrous capsule (outer), synovial membrane (inner)

fibrous capsule

• the outer layer of the joint capsule

  • consists of dense irregular CT + continuous with fibrous layer of periosteum that covers the bones united at the joint

  • portions may thicken + collagen fibers may be regularly arranged to form ligaments

    • ligaments + tendons can be present outside fibrous capsule which contributes to the strength + stability of joint while limiting movement in some directions

synovial membrane

• inner layer of the joint capsule

  • lines the joint cavity except over the articular cartilage + articular disks

  • thin delicate membrane

    • consists of a collection of modified CT, either intermixed with a part of the fibrous capsule or separated from it by a layer of areolar tissue or adipose tissue

fat pads

• prominent areas of adipose tissue that lie between fibrous capsule + synovial membrane

  • helps protect articular cartilage by acting as a cushion around the joint

  • EX: elbow + knee

synovial fluid

• viscous lubricating film that covers the surface of a joint

  • complex mixture of polysaccharides, proteins, lipids, and cells derived from serum filtrate (serum = blood fluid) and secretions from synovial cells

  • Hyaluronic acid is the major polysaccharide that provides much of the slippery consistency + lubricating qualities of synovial fluid

bursae

• pockets of synovial membrane + fluid that extend from joint

  • found in areas of friction

    • tendons rubbing on bones or other tendons

    • subcutaneous olecranon bursae

      • provides cushion between skin + underlying bony prominences where friction could damage the tissue

  • bursitis: inflammation of bursa

ligaments +tendons

used for stabilization in joints

articular discs

• flat pad of fibrocartilage that lies in between the articular cartilages of bone

  • the circumference of the disk is attached to fibrous capsule

  • helps adjust the connection between articulating bones which improves joint stability + reduces wear of articular cartilage

    • EX: temporomandibular, sternoclavicular, acromioclavicular

menisci

• fibrocartilaginous pads in the knee

  • only partially spans synovial cavity where there is an opening in the center

tendon sheath

• synovial sacs that surround tendons as they pass near or over the bone

  • type of bursae

type of synovial joints

1. plane

2. saddle

3. hinge

4. pivot

5. ball-and-socket

6. ellipsoid

three types of movement in synovial joints

1. uniaxial

2. biaxial

3. multiaxial

uniaxial movement

occurring around one axis

biaxial

occurring around two axes at right angles to each other

multiaxial

occurring around several axes

plane joints

consist of two flat bone surfaces of about equal size where a slight gliding motion occurs between

• facet joints

• considered uniaxial

  • some rotation is possible

    • limited by ligaments and adjacent bone

examples of plane joints

• acromioclavicular joint

• carpometacarpal joints

• articular processes between vertebrae

saddle joints

shape of a saddle - convex + concave movement

• biaxial

• the two saddle-shaped articulating surfaces oriented at right angles to one another so their complementary surface articulates

example of saddle joints

• carpometacarpal joint of the THUMB

• sternoclavicular joint

hinge joint

rare —> can be found at the joint at the elbow

• uniaxial

• convex cylinder in one bone is applied to a corresponding concavity in the other bone

• the only hinge joint in the entire body

  • knee somewhat counts but also not.

pivot joints

a relatively cylindrical bony process that rotates within a ring composed partly of bone + ligament

• uniaxial

  • restricts movement to a rotation around a single axis

examples of pivoit joints

proximal radioulnar joint

C1 + C2

ball-and-socket joint

socket that articulates with the ball head

• multiaxial joint

  • wide range of motion in almost any direction

examples of ball-and-socket joints

glenohumeral joint

coxofemoral joint

ellipsoid joint

two slightly rounded joints on top of one another

• AKA condyloid joint

• modified ball-and-socket joint

  • articular surface is in an ellipsoid in shape

• biaxial

  • the shape of joint limits the range of movement almost to a hinge motion in two axes + restricts rotation

examples of ellipsoid joints

• atlantooccipital joint of neck

• joint between C1 and C2

• metacarpophalangeal joints

temporomandibular joint

• between temporal bone + mandible

  • mandibular condyle fits into the mandibular fossa of the temporal bone

• fibrocartilage articular disk is located between mandible + temporal bone

  • divides joint into superior + inferior joint cavities

  • articular disk that may pop

• surrounded by fibrous capsule where the articular disk attaches at its margin

  • strengthened by lateral + accessory ligaments

• combination of planar + ellipsoid joint

  • mostly ellipsoid

process of moving the temporomandibular joint

1. opening of jaw involves inferior cavity of TMJ below the articular disk

2. mandibular condyle rotates anteriorly on disk in the hingelike movement of jaw

3. second portion of jaw opening occurs in superior cavity of TMJ

4. articular disk + condyle glide together anteriorly

   1. similar to the motion that occurs in protraction of mandible

   2. medial lateral movements of the mandibular condyle allow lateral excursion (side-to-side motion of the jaw)

      1. allows for chewing + grinding in mastication

glenohumeral joint

• ball-and-socket

  • less stability but more mobility than the one in the hip

  • flexion, extension, abduction, adduction, rotation, and circumduction can occur here

• rounded head of humerus articulates with glenoid cavity of the scapula

• subacromial bursa and subscapular bursa are present

• the stability of this joint in maintained by four sets of ligaments + four muscles

  • four muscles = rotator cuff

rotator cuff of glenohumeral joint

• holds the humeral head tightly within glenoid cavity

  • head of humerus is also supported with tendon from biceps brachii muscle against the glenoid cavity in the anterior part of the arm

    • this tendon passes through articular capsule of shoulder joint before crossing the head of the humerus + attaching to scapula at the supraglenoid tubercle

subacromial bursa of glenoid cavity

near the joint cavity but is separated from the cavity by the joint capsule

subscapular bursa of glenoid cavity

opens into joint cavity

glenoid labrum

the rim of the glenoid cavity that has a ring of fibrocartilage

dislocation of glenohumeral joint

most common injury of the shoulder

• because major ligaments that cross the superior part of the shoulder joint but no major ligaments or muscles in the inferior side

  • easy to dislocate inferiorly

  • can result in damage to nerves and arteries

elbow joint

• AKA cubital joint

• compound hinge joint

  • consists of humeroulnar joint and humeroradial joint and proximal radioulnar joint

• surrounded by a joint capsule

  • prevents abduction of the elbow

    • ulnar collateral ligament (UCL) prevents this on the medial side

    • radial collateral ligament (RCL) prevents this on the lateral side

• has olecranon bursa

humeroulnar + humeroradial joint

flexion + extension due to the shape of trochlear notch + trochlea interaction

proximal radioulnar joint

pronation + supination occur due to the head of radius rotates in the radial nothch of ulna + against capitulum

olecranon bursa

subcutaneous and covers up the proximal + posterior surfaces of the olecranon process

hip joint

• coxofemoral joint

• femur of head articulates with the relatively deep, concave acetabulum of hip bone

• iliofemoral ligament can support the entire weight of the body

  • hard to disarticulate

• has acetabular labrum

• has transverse acetabular ligament

• fovea capitis holds a ligament from acetabulum to femur

  • houses BV

• capable of flexion, extension, abduction, adduction, rotation, and circumduction

• has a strong joint capsule that is reinforced by several ligaments + extends from the rim of the acetabulum to the neck of the femur

acetabular labrum

• located on the lunate surface of acetabulum

  • lip of fibrocartilage

transverse acetabular ligament

• crosses the acetabular notch on the inferior edge of acetabulum

  • strengthens + deepens the acetabulum

ligament of the head of the femur

• located inside the hip joint between the femoral head + acetabulum

  • does not contribute much toward strengthening the hip joint

  • carries a small nutrient artery to the head of the femur in most people

knee joint

• modified hinge joint

• forms a complex ellipsoid union that allows flexion, extension, and small leg rotation

• distal femur has two large ellipsoid surfaces with a deep fossa between them

• femur only articulates with tibia NOT fibula

  • fibula articulates with the lateral side of tibia

• margin of tibia are built up by menisci

• four major ligaments that stabilize the knee

• joint strength is also provided by popliteal ligaments + tendons of thigh muscles that extend around the knee

• has suprapatellar bursa

four ligaments that stabilize the knee

1. anterior cruciate

2. posterior cruciate

3. medial collateral

4. lateral collateral

suprapatellar bursa

• largest bursae of the knee

  • superior extension of the joint capsule that allows the anterior thigh muscles to move over the distal end of the femur

other bursa in the knee

subcutaneous prepatellar bursa + deep infrapatellar bursa

popliteal bursa

gastrocnemius bursa

subcutaneous infrapatellar bursa

anterior cruciate

1. extend between intercondylar eminence of tibia + fossa of femur

2. prevents anterior displacement of tibia relative to the femur

posterior cruciate

1. extend between intercondylar eminence of tibia + fossa of femur

2. prevents posterior displacement of the tibia

medial collateral

stabilizes the medial side of knee