S

Joints and Movements of the

Body

Objectives

Demonstrate knowledge of the joints of body.

Demonstrate knowledge of the movements of the body.

Apply knowledge to analyze various types of strength-training exercises.

Types of Joints

Joints occur where 2 or more bones meet. Also called articulation. They are held together by ligaments.

Joints are essential for movement.

There are three main types of joints: Fibrous – immovable (skull) Cartilaginous – slightly movable (vertebrae) Synovial – freely movable (shoulder, elbow, knee,

etc.)

Synovial Joints

Freely movable joints that permit movement in one or more directions

5 common types of synovial joints: Ball and Socket joints Hinge joints Pivot joints Saddle joints Gliding joints

Ball and socket joints permit movement in many

directions.

Hinge joints permit back and forth motion.

Pivot joints allow one bone to rotate around another.

Saddle joints permit a wide range of movement

Gliding joints slide past each other.

Structure of Joints – Bursae and Synovial Fluids

In synovial joints, there are small capsules of synovial fluids called bursae.

A bursa acts as a shock absorber and reduces friction between bones of a joint.

Knee Joint

Joint Disorders

Excessive strain on a joint may produce inflammation, in which excess fluid causes swelling, pain, heat, and redness.

Inflammation of a bursa is called bursitis.

Inflammation of the joint itself is called arthritis.

Types of Movement

Flexion – the angle of the joint is decreased.

Extension – the angle of the joint is increased.

Abduction – a body part is moved away from the middle of the body.

Adduction – a body part is moved towards the middle of the body.

Rotation – a body part is moved either outwards or inwards around its long axis.

Types of Movement

Supination – a rotation of the forearm which causes the palm of the hand to face upwards.

Pronation – a rotation of the forearm which causes the palm of the hand to face downwards.

Inversion – a rotation of the sole of the foot inwards.

Eversion – a rotation of the sole of the foot outwards.