Joint Structure & Function Exam 1

• Time, space, and mass aspects of a moving system (book definition)
• Description of human motion/movement
• Types of MOtion
• Location of Movement
• Magnitude of Movement
• Joints Interaction

• Activity that is...
• functional or non-functional
• on-going
• has a specific starting & ending point

Anatomical Position

• Static Position
• Standing Erect
• Head straight with eyes looking forward
• Arms at the side, elbows straight
• Palms of the hands facing forward
• Knees straight
• Toes pointing straight ahead

• Rotary (angular movement)
• Translatory (gliding movement)
• Curvilinear Motion (rotary & translatory movement)
• General Plane Motion (open-chain)

• Movement of an object around a fixed point
• All the parts of the object move through the same angle, in the same direction, and at the same time, but they do not move the same distance.
• ex) Knee flexion: the foot travels farther through space than does the ankle or leg

• Occurs in an "almost" straight line from one location to another
• All the parts of the object move the same distance, in the same direction, and at the same time.
• ex) sutures of the skull or an infant, TMJ (initial stage), carpal bones

• combined rotary & translation movement patterns (FUNCTIONAL)--most common type of movement
• May be fixed or unfixed
• ex) opening your mouth, sliding, spinning or rolling movements

Horizontal plane w/ a longitudinal axis tht divides the body into upper and lower halves

Verticla plane with an anterior/posterior axis that divides the body into front and back halves

Vertical Plane w/ a frontal (coronal) axis hat divides the body into right and left halves

movement around a joint axis where ventral surfaces are being approximated

Approximation of the dorsal surfaces

Distal sigment moves away from the midline

Distal segment moves toward the midline

The segment that is moving is part of the midline of the body

Rotation toward the body's midline

Rotation away from the body's midline

• The measurement of the movement in terms of degrees
• Used to measure ROM, helps to understand the beginning point of patients ability and progression

Kinematic Chains: A movement in one joint is accomplished by movement in adjacent joints

• Open Kinematic Chain: Movement is not predictable--General Plane Motion--more than one way to do something
• Closed Kinematic Chain: Movement is predictable--distal segment is fixed

Study of forces (the forces causing movement)

a push or pull of one object of another object

Gravity, water ressistance, wind

body weight, muscles, tendons, ligaments, diseases

Friction, barometric pressure

• Hypothetical point at which all of our mass is located (balance point)
• Generally near the center of most objects

Anterior to the 2nd sacral vertebra (S₂)

• The larger the base of support--> The greater the stability of the object
• The closer the center of gravity is to the base of support --> the more stable the object

• The joint design is determined by the funtion of the joint and its component parts
• The structure of a joint will determine its function
• Single function joints create stability & complex function joints create mobility

• Creates stability
• ex) sutures in teh cranium

• Creates Mobility
• ex) Hip Joint

208

• Has a thin layer of fibrous periosteum between the two bones
• 1) Synarthrosis
• 2) Syndesmosis
• 3) Gomphosis

ex) sutures of the skull

• Has a thin layer of fibrous periosteum between the two bones, as in the sutures of the skull
• The ends of the bones are shaped to allow them to interlock
• ~no motion between the bones
• Provides shape and strength

• Consists of lots of fibrous tissue (ligaments, interosseous/aponeurotic membranes, holding the joint together)
• Small amount of twisting or stretching
• ex) distal tibiofibular joint at the ankle and the distal radioulnar joint

• Peg-in-socket
• ex) tooth inserted in the socket of the mandible

• Either Hyaline Cartilage or Fibrocartilage b/t the two bones
• Allow a small amount of motion (bending or twisting, and some compression)
• Provide much stability

Cartilaginous Joint composed of fibrocartilage material --symphysis pubis joint

• Hyaline Growth Cartilage in the developing skeletal system ossifies and converts to a body union
• ex)first sternalcostal joint

• Cavity filled with synovial fluid contained within a capsule
• Fibrous tissue holds the joint together
• Synovial fluid lines the inner membrane that secretes the synovial fluid
• Hyaline or Aticulare cartilage line the articular surface
• Allows free motion
• Not as stable as other joints

• Joint Capsule
• Joint Cavity
• Synovial Membrane
• Synovial Fluid
• Hyaline Cartilage

• STRATUM FIBROSUM
• Encapsulates the entire joint structure, made of fibrous tissue

• Enclosed by the entire joint capsule
• -creates space b/t the bones reduces friction
• -needed for articulation

• STRATUM SYNOVIUM
• Lines the inner surface of the capsule
• Creates synovial fluid

Forms a film over the joint surface

• Covers the joint surface
• Found on the ends of long bones

• One plane/axis of movement or 1 degree of freedom
• a) Hinge Joint
• b) Pivot Joint

• Flexion/extension movement
• Occurs in a sagittal plane/frontal axis
• IP joints of the hand

• Rotation
• Occurs in transverse plane/longitudinal axis
• ex) Median atlantoaxial joint: rotation of the skull over the odontoid process of teh axis (C1)

• Two planes/axis of movement or 2 degrees of freedom
• ex) Metacarpal Joints: knuckles of the hands

• Three planes/axis of movement or 3 degrees of freedom
• Motion occurs in a trasverse plane/longitudinal axis, frontal plane/a-p axis, sagittal plane/frontal axis
• ex) ball & socket joints: hip joint: flexion/extension, abduction/adduction, internal roation/external rotation

• Stratum Fibrosum: Outer layer, poorly vascularized but richly innervated w/ joint receptors
• Stratum Synovium: Inner layer, highly vascularized but poorly innervated. Acts as an entry point of nutrients into the synovial fluid and as an exit point for waster products. Also helps produce Synovial Fluid

The loss of ability to perform coordinated movement. Receptors tell the brain where the joints are in relation to space.

• Outer layer of the joint capsule
• Poorly vascularized but richly innervated

• Inner layer of the joint capsule
• Highly vacularized, but poorly innervated
• Entry point of nutrients into the synovial fluid
• Exit point for waste products
• Helps produce synovial fluid

• Hyalutonate (hy-al-uronate)
• Lubricin

Creates viscosity (thickness) of the fluid

• Speed in the Joint (increased speed = decreased viscosity)
• Temperature in the Joint (increased temp. = decreased viscosity)

• Boundary Lubrication: Each weight bearing surface is coated w/ a thin layer of molecules which keeps the opposing surfaces from touching each other
• Fluid Lubrication: Weight on joints increases the hydrostatic pressue of the synovial fluid which causes the articular cartilage to weep fluid over the articular surfaces

The study of movement of the joint surfaces (articular surfaces) and their interaction with each other

• Rolling
• Sliding
• Spinning

Curvilinear Movement

surfaces, joint structure

There are two distinct surfaces resulting in two different movement patterns

Ovoid Joint: one surface is concave and the other surface is convex

Sellar Joint: Each joint surface is convex and concave

• One surface is concave and the other surface is convex
• The articulating surface of the bone moves in an opposite direction of the moving bone-- shoulder bone--

• Each joint surface is convex and concave
• The articulating surface of the bone moves in the same direction as the moving bone
• ex) the knee joint

• The movement of bones rather than the movement of the articulating surface
• Important CLINICALLY

Range of Motion (ROM)

• Range which is availabe to a joint w/in the anatomical limits of the joint. The anatomical limits are determined by
• --Shape of the joint surface
• --The joint capsule
• --Ligaments
• --Muscle bulk
• --Surrounding Structures

Increased/Accessive ROM

Limited ROM

No longer functional movement in the joint (locked/fixed) more common w/ flexors

Connective tissue in the form of ligaments, tendons, bursae, cartilage, disks, plates, menisci, fat pads, etc.

• Cellular Component: produce/maintain extracellular matrix
• Extracellular Matrix: non-firbrous component & fibrous component

• Produce/Maintain extracellular matrix
• Antibodies to fight infection in connective tissue

• Provides support
• Attracks and binds water
• Maintains hydration w/in the tissue w/ proteins (glycoprotein/proteoglycans)

• Provides a support framework with the use of the 2 Proteins
• --Collagen = Strength
• --Elastin = Flexibility--yellow substance

• 20% cellular components
• 80% extracellular matrix: primarily the fibrous component--mix of elastin & collagen

In tendons, the COLLAGEN PROTEIN dominate and is structured in PARALLE ARRANGEMENTS with the tendon.

• Flat like sac with the inner lining of the sac composed with a synovial membrane. This embrane keeps the sac fille diwth a fluid film.
• Located where movement occurs