Articulations

Chapter 8

Structural Classification of Joints

• Fibrous• no joint cavity, bones held together with collagen fibers

• Cartilagnous• no joint cavity, bones held together with cartilage

• Synovial• have a “synovial” cavity, bones held together with an enclosed capsule & ligaments

Functional Classification of Joints

• Synarthroses (singular = synarthrosis)– Immovable joints

• Amphiarthroses (singular = amphiarthrosis)– Slightly movable joints

• Diarthroses (singular = diarthrosis)– Freely movable joints

Suture: a fibrous synarthrosis

Synchondrosis: a cartilaginous synarthrosis

Syndesmosis: a fibrous amphiarthrosis

An amphiarthrotic synchondrosis

Symphysis: a cartilaginous amphiarthrosis

Synovial Joints

The shoulder joint

Types of Movements Possible at Synovial Joints

Gliding

Flexion

Flexion decreases the angle of a joint

Extension

Extension increases the angle of a joint

Extension of the

shoulder

Hyperextension moves a jointbeyond the

usual extended angle

Movements of the neck

Special movement of the ankle

Abduction,Adduction

&Circumduction

Rotation

Special movements of the antebrachium

Special movements of the foot

You can do this with your hips &

shoulders too!

Also possible with shoulders (but not hips)

Ok?

Types synovial joints

Hingejoints

These are uniaxial.Examples include the elbow, knee and phalanges.

Pivot

Pivot joints are uniaxial.The proximal radioulnar joint is the best example.

Condyloid joints

Condyloid joints are often biaxial.

Saddle joints

Saddle joints are biaxial.

Ball and Socket

Multiaxial ball & socket joints allow the greatest range of motion.

Structural Details of Some Synovial Joints

The Shoulder

Capsule of the

shoulder

The Hip

Extracapsular ligaments of the hip a.

Extracapsular ligaments of the hip b.

The Elbow

The Elbow b.

The Elbow reverse view

The Knee

Anterior view of

the knee

Extracapsular ligaments of

the knee

Common knee injury

ACL replacement

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