Chapter 9 Joints

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Chapter 9Joints

• Arthrology is the study of the joints
• Kinesiology is the study of musculoskeletal
  movement

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2 CLASSIFICATION OF JOINTS

• 1. How the bones are joined
• fibrous, cartilaginous, bony and synovial joints
• 2. How the bones move
• We will look at this type of joint mainly

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Three types of Joint MOVEMENT

• Three ways bones move
• 1. Freely
• 2. Slightly
• 3. Not at all
• A freely moving joint is a DIARTHROSES
• This includes All synovial joints
• Slightly moving is a AMPHIARTHROSIS
• No movement is a SYNARTHROSIS

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SYNARTHROSIS

• Synarthrosis ( How much does this move?), three
  types
• 1. Suture
• 2. Gomphosis
• Teeth
• 3. Synchondroses (SYN together, chrondro
  cartilage
• Epiphyseal plate

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AMPHIARTHROSIS

• Amphiarthrosis (moves ________), two types
• 1. Syndesmosis (struck rock twice)
• Distal tibiofibular joint
• (picture tibula and fibula stricking each other)
• 2. Symphyses
• Always in the midline of the body
• Pubic symphyses
• Intervertebral disc

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Making Sense of JointsCartilage becomes Bone

• A Synchondrosis 2 bones, once separate, fused by
  osseous tissue
• An example is the epiphyseal plate at the end of
  growing bones
• As the bone grows the synchondrosis (cartilage)
  is replaced by bone and becomes a synostosis
  (ost- is bone)

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Synarthrosis Joints(Immovable Joint)

• Synathrosis
• Fibrous joints of collagen fibers in space
  between bones
• sutures, synchondroses, synostosis, gomphosis

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Amphiarthrosis(Slightly Moveable Joint)

• Symphysis
• pubic symphysis and intervertebral discs
• Syndesmosis
• Distal tibia and fibula joint

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Diarthrosis (Freely Moveable) I

• Space between bones called the synovial (joint)
  cavity
• Contains articular capsule and an articular
  cartilage
• 1. Articular capsule is composed of two layers
• 1) the outer fibrous capsule
• lined by synovial membrane
• continuous with periosteum
• 2) the inner synovial membrane
• a) which secretes a lubricating and
  joint-nourishing synovial fluid
• viscous slippery fluid rich in albumin
  similar to raw egg white
• 2. Articular cartilage
• hyaline cartilage covering the joint surfaces

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Diarthrosis (Freely Moveable) II Synovial Joint
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Diarthrosis (Freely Moveable) III

• Many diarthroses also contain accessory
  structures
• Extracapsular and intracapsular ligaments
• Collateral ligaments of knee
• Cruciate ligaments of knee
• Articular discs
• Meniscus is a pad of fibrocartilage injaw,
  wrist, knee and sternoclavicular joints
• absorbs shock, guides bone movements
• Bursae
• Found between tendons, muscles, ligaments and
  bones
• Tendon attaches muscle to bone
• Ligament attaches bone to bone

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Bursae and Tendon Sheaths

• Bursa is a sac, an extension of joint capsule
  that are between nearby structures allowing them
  to slide more easily past each other
• Tendon sheaths are cylinders lined with synovial
  membrane that wrap around a tendon
• numerous in hand and foot
• Tenosynovitis inflammation of the tendon sheaths
  and synovial membranes
• Tendonitis inflammation of _________.

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TYPES OF DIARTHROSES
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Ball-and-Socket Joints

• Smooth hemispherical head fits within a cuplike
  depression
• head of humerus into glenoid cavity of scapula
• head of femur into acetabulum of hip bone
• Multiaxial joint

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Hinge Joints

• One bone with convex surface that fits into a
  concave depression on other bone
• ulna and humerus at elbow joint
• femur and tibia at knee joint

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Saddle Joints

• Each articular surface is shaped like a saddle,
  concave in one direction and convex in the other
• trapeziometacarpal joint at the base of the thumb

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Pivot Joints

• One bone has a projection that fits into a
  ringlike ligament of another
• First bone rotates on the other
• atlantoaxial joint (dens and atlas)
• proximal radioulnar joint
• the radius during pronation and supination

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Gliding Joints

• Flat surfaces in which bones glide over each other

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Condyloid (ellipsoid) Joints

• Oval convex surface fits into a concavity
• radiocarpal joint of the wrist
• metacarpophalangeal joints at the bases of the
  fingers

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Special Movements of Diarthroses

• Flexion decreases the angle of a joint
• bending elbow or wrist
• Extension increases the angle of a joint
• Straighten elbow
• Hyperextension is extension of a joint beyond 180
  degrees

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Flexion, Extension Hyperextension
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Abduction Adduction

• Abduction is movement of a part away from the
  midsagittal line -- raising the arm to the side
• Adduction is movement adding to midline

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Abduction Adduction

• Abduction is spreading the fingers away from the
  midline (middle finger)
• Adduction is movement is returning the fingers to
  the anatomical position

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Elevation and Depression

• Elevation is a movement that raises a bone
  vertically
• mandibles are elevated during biting clavicles
  during a shrug
• Depression is lowering the mandible or the
  shoulders

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Protraction Retraction

• Protraction is movement of a bone anteriorly
  (forward) on a horizontal plane
• thrusting the jaw forward
• scapula
• Retraction is movement of a bone posteriorly

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Circumduction

• Combines flexion, abduction, extension
  adduction
• baseball player winding up for a pitch
• NOT Rotation
• (but it looks like it)

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Lateral and Medial Rotation

• Movement of a bone turning
• rotation of trunk, thigh, head or arm
• Medial rotation turns the bone inwards (internal
  rotation)
• Lateral rotation turns the bone outwards
  (external rotation)

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Supination/ Pronation

• Occurs in the forearm
• Supination (get soup)
• rotation of forearm so that the palm goes from
  the posterior to the anterior
• Pronation (pour it out)
• rotation of forearm so the palm goes from
  anterior to posterior

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Inversion Eversion

• Dont use supination and pronation for the feet,
  use
• Inversion
• raising the medial edge of the foot
• Eversion of foot
• lowering the medial edge of the foot (Adam and
  Eve fell)

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Plantar Flexion Dorsiflexion

• The foot does not extend
• Dorsiflexion is raising of the toes as when you
  swing the foot forward to take a step (heel
  strike)
• Plantarflexion is when the toes point downward as
  in standing on tiptoe (or planting a rose between
  your toes)

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Opposition Reposition

• Opposition is movement of the thumb to approach
  or touch the fingertips
• Reposition is movement back to the anatomical
  position
• Important hand function that enables the hand to
  grasp objects (us vs. apes)

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The Humeroscapular Joint

• Shoulder is most freely movable joint in the body
• shallowness of glenoid cavity looseness
  ofcapsule (golf ball in a shot glass)
• Supported by ligaments tendons
• Supported by rotator cuff musculature
• supraspinatus, infraspinatus,
• teres minor subscapularis
• (L is for lateral rotation and
• M is for medial rotation)

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Tendons of Rotator Cuff MusclesWhere is
dislocation more likely?
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The Pitcher

• To throw a baseball a pitcher has to use her
  shoulder muscles
• 1) To ________ to 10 degrees she will use her
  supraspinatus muscle
• 2) To fully abduct, she will use her _______
  muscle
• 3) To bring her humerus into lateral rotation she
  will use her ______ and _______ muscle
• 4) And to throw, she will bring her humerus into
  _____ rotation by using her subscapularis muscle.

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The Elbow Joint

• Single joint capsule enclosing the humeroulnar
  and humeroradial joints
• Radioulnar and Humeroulnar joint

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The Hip Joint

• Head of femur articulates with acetabulum
• Socket deepened by acetabular labrum
• transverse acetabular ligament completes labrum
• Blood supply to head of femur found in ligament
  of the head of the femur (round ligament)

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Joint Prostheses
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The Knee

• Most complex diarthrosis of the body
• patellofemoral gliding joint
• tibiofemoral gliding with slight rotation
  gliding possible in flexed position
• Joint capsule anteriorly consists of patella
  extensions of quadriceps femoris tendon

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Knee Joint I

• Medial lateral meniscus absorb shock shape
  joint

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Knee Joint II

• The knee has four major ligaments two to limit
  sliding from side to side (collaterals) and front
  to back (cruciates)
• Medial and lateral collateral ligaments prevent
  rotation of extended knee and side to side slide
• Anterior lateral cruciate ligaments limit
  anterior posterior sliding movements (anterior
  cruciate is on the anterior of the tibia, the
  posterior cruciate is on the posterior _______.
• We use the AP draw test to evaluate these
  ligament

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The Ankle Joint

• One joint capsule enclosing the joints between
  the talus, tibia and fibula
• Groups of ligaments
• deltoid ligament binding the tibia to the foot on
  the medial side (never sprained)
• lateral collateral ligament binds the fibula to
  the foot on the lateral side (most ankle sprains)
• achilles tendon inserting on the calcaneus

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Dissection of Ankle Joint
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JOINT DISORDERS

• Dislocation (luxation) a total displacement of
  a joint with tearing of ligaments, tendons, and
  articular capsules (Example shoulder)
• Subluxation a slight dislocation causing
  structural and neural dysfunction (Example
  spine)
• Sprain ligament wrenching (i.e. sprained ankle)
• torn ligaments or tendons
• Strain muscle over stretching

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Arthritis

• Arthritis is a broad term for pain inflammation
• Blood test may make the diagnosis and/ or X-ray
  findings
• Gouty arthritis
• Involves sodium urate crystals deposited in soft
  tissues of joints, causing inflammation,
  swelling, and pain
• Major features Great toe, One joint, Uric acid
  increased, Temperature dependent
• Osteoarthritis results from years of joint wear
• articular cartilage softens and degenerates
• accompanied by crackling sounds called crepitus
• bone spurs develop on exposed bone tissue causing
  pain
• Rheumatoid arthritis is autoimmune attack on
  joint
• antibodies attack synovial membrane, enzymes in
  synovial fluid degrade the cartilage, bones
  ossify, remissions occur

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Rheumatoid Arthritis
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Rheumatoid Arthritis