articulations (joints). connect 2 bones. connect 2 bones. classified by structure or function...

Articulations (Joints)Articulations (Joints)

• Connect 2 bones.Connect 2 bones.

• Classified by structure or functionClassified by structure or function

Joint classificationJoint classificationClassification by Classification by

structurestructure

• 1. Fibrous joints1. Fibrous joints- bones held - bones held

together by fibrous together by fibrous connective tissueconnective tissue

• 2. Cartilagenous 2. Cartilagenous jointsjoints

- bones held - bones held together by cartilagetogether by cartilage

• 3. Synovial joints3. Synovial joints - complex - complex

structure with structure with cartilage and cavitiescartilage and cavities

Classification by functionClassification by function

• 1. Synarthroses1. SynarthrosesImmovable jointsImmovable joints

• 2. Amphiarthrose2. AmphiarthroseSlightly movable jointsSlightly movable joints

• 3. Diarthroses3. DiarthrosesFreely movable jointsFreely movable joints

General backgroundGeneral background

• 1 extra joint category1 extra joint category

Bony joint (Bony joint (synostosissynostosis))•Immobile (immovable)Immobile (immovable)•Fond when 2 bones ossify together Fond when 2 bones ossify together

(essentially merge or weld together)(essentially merge or weld together)•Some cranial sutures (fissures in the Some cranial sutures (fissures in the

cranium) become ossifiedcranium) become ossified

•When the growth plate fuses/calcifies When the growth plate fuses/calcifies over (joining the epiphysis and diaphysis over (joining the epiphysis and diaphysis in long bones)in long bones)

Fibrous joint Fibrous joint ((synarthrosissynarthrosis))

• 11.. SutureSuture

• 2. Gomphosis2. Gomphosis

• 3. Syndesmosis3. Syndesmosis

1. Sutures1. Sutures

SutureSuture: : immobile joints in the immobile joints in the skull (the fissures you skull (the fissures you see) through the see) through the thickness of the outer thickness of the outer compact bonecompact bone-“serrate”-“serrate” = wavy lines = wavy lines

(like a serrated knife) (like a serrated knife) - skull: - skull:

parieta/frontal bonesparieta/frontal bones

- ““lap”/ “squamous”lap”/ “squamous” = = diagonal linediagonal line

- Skull: temporal/parietal Skull: temporal/parietal bonesbones

- ““plane” / “butt”plane” / “butt” = = straight linestraight line

- Paired maxillary and Paired maxillary and palatine bonespalatine bones

• where teeth attach to bonewhere teeth attach to bone• Tooth is “held in place” by fibrous Tooth is “held in place” by fibrous

peridontal ligament” made of peridontal ligament” made of collagen that originates from the collagen that originates from the jaw bonejaw bone

• Fibrous “joint” permits slight Fibrous “joint” permits slight movement when bitingmovement when biting

• An important sensory mechanism An important sensory mechanism that lets you know how hard or that lets you know how hard or soft you are bitingsoft you are biting

2. Gomphosis2. Gomphosis

Gingivitis (gum disease)Gingivitis (gum disease)

• Bacterial infection Bacterial infection destroys the ligament destroys the ligament holding the teeth in holding the teeth in placeplace

• Promoted by the Promoted by the presence of plaquepresence of plaque

ScurvyScurvy• A chronic lack of vitamin A chronic lack of vitamin

C leads to scurvyC leads to scurvy

• Vitamin C is necessary Vitamin C is necessary for collagen synthesisfor collagen synthesis

• With decreased collagen With decreased collagen synthesis, joints are synthesis, joints are weakened, wounds do weakened, wounds do not heal well.not heal well.

• How do you treat How do you treat scurvy?scurvy?

3. Syndesmosis3. Syndesmosis

• Colllagen fibers bind 2 Colllagen fibers bind 2 bonesbones

• More mobility than suture More mobility than suture or gomphosis, but still or gomphosis, but still very limitedvery limited

• Tibia – fibula at distal endTibia – fibula at distal end

• Radius – ulna at distal Radius – ulna at distal endsends

Tibia/fibula Radius/ulna

Note how far apart the radius/ulna are from one another compared to the tibia/fibula. This is one reason why your forearm is more “mobile” or flexible than your lower leg.

Cartilaginous joints: Cartilaginous joints: ((amphiarthrosisamphiarthrosis))

1.1. SynchondosesSynchondoses: : when bone is when bone is bound /joined bybound /joined by hyalinehyaline cartilage cartilage

• The growth plate in The growth plate in long boneslong bones

• The first rib The first rib attaches to the attaches to the sternum (ONLY the sternum (ONLY the first rib)first rib)

2.2. SymphysesSymphyses: where : where bones are joined bones are joined by by fibrousfibrous cartilage cartilage

• Pubic bone (pelvis)Pubic bone (pelvis)

• Between vertebraeBetween vertebrae

Trick questionTrick question

• How/why do infants and children How/why do infants and children have more joints than adults?have more joints than adults?

Synovial jointsSynovial joints

- - Very complexVery complex

- ““synovial” joint synovial” joint because the joints are because the joints are separated by a space separated by a space (“synovial cavity”), (“synovial cavity”), where synovial fluid is where synovial fluid is retainedretained

- Synovial fluid rich in Synovial fluid rich in albumin (blood protein) albumin (blood protein) and hyaluronic acid (a and hyaluronic acid (a lubricant)lubricant)

Synovial jointsSynovial joints- Joint membrane:Joint membrane:

- Outer fibrous capsule (continuous Outer fibrous capsule (continuous with the periosteum)with the periosteum)

- Inner synovial membrane Inner synovial membrane secretes the synovial fluid into secretes the synovial fluid into the joint capsulethe joint capsule

- Each bone involved in the joint Each bone involved in the joint is covered by articular cartilage is covered by articular cartilage 2 mm thick 2 mm thick

-The bones making up the joint are -The bones making up the joint are “held together” by ligaments“held together” by ligaments

• Help to locate the bones in the correct Help to locate the bones in the correct “place” so that their articular “place” so that their articular cartilage “rides” correctlycartilage “rides” correctly

Types of joints: classification by shapeTypes of joints: classification by shape

• Ball & SocketBall & Socket joints joints (hip and shoulder)(hip and shoulder)

• Hinge jointsHinge joints (ulna and (ulna and femur…knee, fingers femur…knee, fingers and toes)and toes)

• Pivot jointsPivot joints (radius and (radius and ulna…forearm/elbow ulna…forearm/elbow and the first 2 and the first 2 vertebrae of your vertebrae of your spine)spine)

• Saddle jointsSaddle joints (thumb, (thumb, sternum/clavicle)sternum/clavicle)

• Condyloid jointsCondyloid joints (fingers)(fingers)


• Ball & SocketBall & Socket joints joints (hip and shoulder)(hip and shoulder)

• The ONLY multi-The ONLY multi-directional joints you directional joints you havehave


• Ball & Socket jointsBall & Socket joints

• Hinge jointsHinge joints (ulna (ulna and femur…knee, and femur…knee, fingers and toes)fingers and toes)

• 1 range of movement 1 range of movement (flip-phone)(flip-phone)


• Ball & SocketBall & Socket

• Hinge jointsHinge joints

• Pivot jointsPivot joints (radius and (radius and ulna…forearm/elbow and ulna…forearm/elbow and the first 2 vertebrae of the first 2 vertebrae of your spine)your spine)

• When 1 bone spins on When 1 bone spins on another, when you say another, when you say no, or turn a door knob)no, or turn a door knob)


• Ball & SocketBall & Socket jointsjoints


• Pivot jointsPivot joints

• Saddle jointsSaddle joints (thumb, (thumb, sternum/clavicle)sternum/clavicle)

• 2 ranges of motion 2 ranges of motion (hold something tight (hold something tight = sagittal plane, = sagittal plane, spread hand = frontal spread hand = frontal plane)plane)

• Condyloid jointsCondyloid joints (fingers)(fingers)

• 2 ranges of motion: 2 ranges of motion: make a fist = sagittal make a fist = sagittal plane, spread fingers plane, spread fingers = frontal plane= frontal plane


• Ball & SocketBall & Socket jointsjoints


• Pivot jointsPivot joints

• Saddle jointsSaddle joints • Condyloid jointsCondyloid joints

• Gliding jointsGliding joints• Bone surface almost Bone surface almost

flatflat• Bones slide along Bones slide along

each othereach other• Ex: carpal bone, Ex: carpal bone,

patella-femurpatella-femur

Complex jointsComplex joints

Many joints have characteristics of Many joints have characteristics of multiple joint typesmultiple joint types

• Elbow is both a hinge joint (where ulna and Elbow is both a hinge joint (where ulna and humerus meet), as well as a pivot joint humerus meet), as well as a pivot joint (where radius and ulna meet)(where radius and ulna meet)

• Knee is similar to the elbow joint, without as Knee is similar to the elbow joint, without as much flexibility (much stronger and limited)much flexibility (much stronger and limited)

• Temporo-mandibular joint has both lateral Temporo-mandibular joint has both lateral and dorsal/ventral movementand dorsal/ventral movement

Complex synovial jointsComplex synovial joints

• In a few joints (jaw = In a few joints (jaw = temporo-mandibular), temporo-mandibular), (sternum/collarbone (sternum/collarbone =sterno-clavicular), =sterno-clavicular), (ankle = distal tibia-(ankle = distal tibia-fibula), there is an fibula), there is an articular discarticular disc

• In your knee, this is In your knee, this is called a meniscuscalled a meniscus

• for guidance of the knee for guidance of the knee bonesbones

• for shock absorptionfor shock absorption

Accessories to synovial Accessories to synovial jointsjointsOther structures present in Other structures present in

synovial joints:synovial joints:

• Tendons: Tendons: collagen-based collagen-based connective tissue that hold connective tissue that hold muscle to bonemuscle to bone

• Ligaments: Ligaments: collagen-based collagen-based connective tissue that hold bone connective tissue that hold bone to boneto bone

• Bursa: Bursa: fibrous “sac” that fibrous “sac” that holds synovial fluidholds synovial fluid– Wraps around muscles Wraps around muscles

prevent rubbingprevent rubbing– ““bursitis” = inflammation of bursitis” = inflammation of

the bursathe bursa– ““tendon sheath” tendon sheath”

BursaBursa

Movements of various Movements of various jointsjoints

Your shoulder (ball and socket) is a good example of a joint that is “multiarticulate”

The ball and socket allows for:

•Abduction of the arm (flap your arms like a bird, jumping jacks)

•Flexion of the arm (extending to shake a hand or open a door)

•Rotation of the arm (sweeping your desk)


Abduction = raising arms above head (moving away from the anatomical position in the FRONTAL PLANE)

Adduction = returning arms to side (returning to anatomical position in the FRONTAL PLANE)

The terms abduction and adduction refer to the ACTION, NOT THE APPENDAGE that you are moving (you can also

abduct and adduct your legs at the hip joint).


Elevation = lifting body part in the FRONTAL PLANE (moving away from the anatomical position)

In this case, the model is raising their shoulders in the frontal or coronal plane

Depression = returning to anatomical position from elevation

These terms refer to movement FROM the anatomical position, as well as back TO the anatomical position. These movement terms also refer to the PLANE of movement. In this case, we are dealing with the FRONTAL or CORONAL plane.


Protraction = moving body part forward (anterior movement) in a transverse or horizontal direction

Retraction = posterior movement (“pushing out” his chest…he’s really pulling back his shoulders”)

With these terms, there is reference to direction and plane of movement, however, this DOES NOT refer to the movement FROM or TO the anatomical position.


Flexion = decreasing joint angle

In this case, the models elbow is in flexion

Extension = increasing joint angle to “zero position” (where it would “naturally rest)

Hyperextension = moving beyond the zero position

Note that this movement DOES NOT refer to the plane of a joint, is only refers to the ANGLE of the joint.


Hyperextension = moving beyond the zero position


Circumduction = 1 end of the joint remains stationary, the other end makes a CIRCLE.

Rotation = turning a joint longitudinally

on 1 bone of the joint


Supination =ONLY for FOREARM, when you turn your forearm so that the palms face forward or ventral (anatomical position)

Pronation = ONLY for the forearm, when you turn your forearm so that the palm faces posterior or dorsal

Movements of hand jointsMovements of hand jointsRadial flexion = tilting the hand towards the thumb (towards the radius)

Ulnar flexion = tilting hand towards the pinky finger (towards the ulna)

Abduction of the FINGERS is when you spread your fingers apart

In terms of your fingers:

Flexion = curling fingers (like a fist)

Extension = pointing your fingers

Movements of hand jointsMovements of hand jointsYour THUMB is turned 90 from the rest of your fingers, so the previous “terms” for finger movement are DIFFERENT for your thumb

Abduction = bring your thumb to your index finger (the “OK” sign)

Opposition = touch pinky with thumb

Reposition = return to “zero” from the opposition position

In terms of your THUMB:

Flexion = bending towards the palm of your hand

Extension = pointing thumb up (hitch-hiking)

Hyperextension = when you make a 90 angle between your thumb and index finger (straight up

hitch hiker thumb)

Movements of foot/ankle Movements of foot/ankle jointsjoints

In terms of ANKLE movements

Dorsiflection = lift toes up (standing on your heels)

Zero position = feet flat on the ground, standing up

Plantar flexion = pointing toes down (standing on your toes)

In terms of your FEET:

Your ankle can “roll” just like your wrist can “wave”

Inversion = turning the plantar surface towards the median (standing on the outside of your feet)

Eversion = turning the plantar surface laterally (standing on the arches of your feet)

Complex joint: humero-Complex joint: humero-scapular joint (shoulder)scapular joint (shoulder)

• The scapula is The scapula is connected to the connected to the thorax only by the thorax only by the clavicle (collar clavicle (collar bone)bone)

• Connection at the Connection at the acromion process acromion process (look for a sharp (look for a sharp hook) hook)

• The joint between The joint between the clavicle and the clavicle and acromion = acromion = acromial-clavicular acromial-clavicular jointjoint

Humero-scapular jointHumero-scapular joint

Anterior viewPosterior view

Note how the ligaments and tendons wrap around the joint to hold the head of the

humerus into the glenoid cavity. Also note how shallow the “socket” on the scapula is; an effort to increase mobility of this joint

• Loose ball and Loose ball and socket joint.socket joint.

• More mobilityMore mobility

• Muscles and Muscles and ligaments ligaments stabilize the stabilize the jointjoint

Complex joint: Elbow jointComplex joint: Elbow jointActually 2 joints in 1 areaActually 2 joints in 1 area• Humero-ulnar jointHumero-ulnar joint• Humero-radial jointHumero-radial joint

– Both enclosed by 1 Both enclosed by 1 single synovial joint single synovial joint capsulecapsule

• 33rdrd joint in the elbow: joint in the elbow: radio-ulnar jointradio-ulnar joint

• head of the radius - head of the radius - radial notch in the radial notch in the ulnusulnus

• important because it important because it permits the forearm permits the forearm rotation (supine/prone) rotation (supine/prone) rotationrotation

• Your tibia/fibula (shins) Your tibia/fibula (shins) cannot rotate as wellcannot rotate as well

Features of the hand and Features of the hand and wristwrist

Also remember that your hand and wrist comprise a number of different joint types: saddle, gliding and condyloid. Together, these joints give your hands and fingers a

great deal of and mobility

Costovertebral jointsCostovertebral joints

Hip joint: Coxal bone - Hip joint: Coxal bone - femurfemur

Knee and hip replacementsKnee and hip replacements

Rheumatoid arthritisRheumatoid arthritis

- An autoimmune disease

OsteoarthritisOsteoarthritis- Bone degeneration due to old age

Osteoarthritis of the spinal Osteoarthritis of the spinal cordcord

BursitisBursitis

• Accumulation of Accumulation of synovial fluid in the synovial fluid in the bursa – due to bursa – due to chronic or acute chronic or acute irritationirritation

• An extreme case!An extreme case!

Sprain and StrainSprain and Strain

• Sprain: ligament Sprain: ligament teartear

• Strain: Tendon Strain: Tendon or muscle tearor muscle tear

articulations (joints). connect 2 bones. connect 2 bones. classified by structure or function...

Documents

fibrous joints bones

cartilaginous joints

immobile joints

cartilagenous joints

shoulderhinge joints

toespivot joints radius

joint capsuleeach bone

shapeball socket joints