Joints Flashcards
Joints
Muscles are attached to bones; when the muscles contract, they pull on the bones and movement occurs. Where two or more bones meet, they form a joint.
Types of Joints
- Fixed or fibrous
- Cartilaginous
- Synovial
Fixed or fibrous
No movement e.g Skull, pelvis, radioulnar and tibiofibular
joints
Cartilaginous
Slight movement e.g. Ribs attaching to sternum, lumbar vertebrae
Synovial
Free moving e.g. Hip and knee joints, cervical and thoracic
vertebrae
Types of Synovial Joints
- Pivot
- Gliding
- Ball and socket
- Hinge
- Saddle
- Condyloid
Pivot
Structure: A uniaxial joint that only allows rotation
Movement: Rotation of one bone around another
Example: Atlas and Axis
Gliding
Structure: Occurs where flat bones glide past each other, usually in a biaxial manner
Movement: Gliding movements
Example: Carpals / Tarsals
Ball and Socket
Structure: Occurs where a rounded bone head articulates with a cup-shaped cavity
Movement: Flexion, extension, adduction, abduction, internal and external rotation
Example: Shoulder, hip
Hinge
Structure: A uniaxial joint
Movement: Flexion, extension
Example: Knee, elbow
Saddle
Structure: Occurs where concave and
convex bone surfaces align; generally biaxial
Movement: Flexion, extension, adduction, abduction, circumduction
Example: Carpo-metacarpal joint of thumb
Condyloid
Structure: Very similar to a hinge joint
but also allows slight rotation; hence, is biaxial
Movement: Flexion, extension, adduction, abduction, circumduction
Example: Wrist
Flexion
The angle between articulating bones is decreased and flexion occurs in the median plane about a horizontal axis
Extension
The angle of the joint is increased and extension occurs in the median plane about a horizontal axis
Abduction
This is movement of a body part away from an imaginary midline of the body
Adduction
This is movement of a body part towards an imaginary midline of the body
Rotation
Rotation occurs when a bone turns on its own axis within a joint. Rotation towards the body’s midline is known as medial or internal rotation; rotation away from the midline is known as lateral or external rotation
Circumduction
Circumduction occurs when a limb moves in a circular fashion and is generally only possible at ball and socket joints because flexion, extension, abduction and adduction are required. This occurs in the median and frontal planes
Supination
Supination occurs when the forearm is rotated, turning the hand from palm down to palm up, so that
the radius and ulna lie parallel to each other and are uncrossed
Pronation
Pronation occurs when the forearm is rotated while the palm of the hand faces downwards. When this occurs, the radius and the ulna are crossed over each other
Dorsiflexion
Dorsiflexion occurs at the ankle when the toes are pointing towards the tibia and are generally higher
than the heel. This occurs in the median plane about a horizontal axis
Plantarflexion
Plantarflexion occurs at the ankle when the toes are pointed downwards and the heel is raised.
This occurs in the median plane about a horizontal axis
Inversion
Inversion occurs when the sole of the foot is turned inwards towards the imaginary midline of the body. This occurs is in the frontal plane
Eversion
Eversion occurs when the sole of the foot is turned outwards from the imaginary midline of the body. This occurs is in the frontal plane
