Presentation on theme: "Chapter 9 Articulations. Point of contact between bones. Joint- mostly very movable but some are immovable or only allow limited motions. Movable joints."— Presentation transcript:
Chapter 9 Articulations
Point of contact between bones. Joint- mostly very movable but some are immovable or only allow limited motions. Movable joints allow complex, highly coordinated movements.
Classifications Structural classification- joints are named according to: – Type of connective tissue – Presence of fluid filled joint capsules Functional classification- – Synarthroses- immovable – Amphiarthroses- slightly movable – Diarthroses- freely movable
Fibrous Joints Synarthroses Bones of joints fit together closely, allowing little or no movement. – Syndesmoses- joints in which ligaments connect two bones. – Sutures- found only in skull; toothlike projections from adjacent bones interlock with each other. – Gomphoses- between root of a tooth and the alveolar process of mandible and maxilla.
Cartilaginous joints Bones of joints are joined together by hyaline cartilage of fibrocartilage; allow very little motion.
Types of Synovial Joints Multiaxial joints – Ball and socket joint- shoulder, femur – Gliding joint- wrists, vertebrae
Humeroscapular Joint Shoulder joint Most mobile joint because of glenoid cavity Glenoid labrum
Elbow Joint Humeroradius joint Humeroulnar joint Both components of elbow joint surrounded by single joint capsule and stabilized by collateral ligaments.
Hip Joint Stable joint
Knee Joint Largest and one of the most complex and most frequently injured joints. Tibiofemoral joint- supported by joint capsule, cartilage, ligaments, and tendons. Permits flexion and extension
Ankle Joint Hinge type of synovial joint Articulation between lower ends of tibia and fibula and upper part of talus. Joint is “mortise” or wedge-shaped. – Lateral malleolus lower than medial.
Measuring Range of Motion Range of motion (ROM) assessment used to determine extent of joint injury. ROM can be measured actively or passively; results of both by instrument called goniometer.
Angular Movement Change in the size of angle between articulating bones. – Flexion- decreases angle between bones; bends or folds one part on another. – Extension- increases angle between two bones. – Hyperextension- extension between bones of a joint that is greater than normal. – Plantar flexion- increases angle between top of foot and front of leg.
Angular Movement – Dorsi flexion- decreases angle between top of foot and front of leg. – Abduction- moves part away from median plan of body. – Adduction- moves a part toward median plane of body.
Circular Movements Rotation- pivoting a bone on its own axis. Circumduction- moves a part so that its distal end moves in a circle. Supination- turns the hand palm side-up. Pronation- turns the hand palm side-down.
Gliding Movements Simplest of all movements; articular surface of one bone moves over articular surface of another without any angular or circular movement.
Special Movements Inversion- turning sole of foot inward. Eversion- turning sole outward. Protraction- moves a part forward. Retraction- moves part backward. Elevation- moves part up. Depression- lowers a part.