Section 26: Joints Types and Movement 26-1 Synovial joints: - - PDF document

Section 26: Joints – Types and Movement

26-1

Synovial joints: stability Synovial joints: stability

• Stability is determined by:

Stability is determined by:

– Articular surfaces – shape determines what movements are possible movements are possible – Ligaments – unite bones and prevent excessive or undesirable motion excessive or undesirable motion – Muscle tone

26-2 From: Mathis

Synovial joints: stability Synovial joints: stability

• Muscle tone is accomplished by:

Muscle tone is accomplished by:

– Muscle tendons across joints acting as stabilizing factors stabilizing factors – Tendons that are kept tight at all times by muscle tone muscle tone

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Terms

• Pivot Point – The point that the joints rotate

about.

• The fundamental movements are roll, slide, and

spin.

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More Terms More Terms

• Motion – Either active or passive

Motion Either active or passive

– Active is the patients movement of his or her arm – Passive is the examiners movement of the patient’s p arm

• Extension – Natural movement opposite to

flexion at the zero position.

• Hyperextension – Unnatural motion opposite to

fl i t th iti flexion at the zero position.

26-5 From: IPRO

26-6 From: Hoxha

Types of synovial joints Types of synovial joints

• Hinge joints

Hinge joints

– Cylindrical projections of one bone fits into a trough-shaped surface on another trough shaped surface on another – Motion is along a single plane – Uniaxial joints permit flexion and extension – Uniaxial joints permit flexion and extension

• nly

26-7 From: Mathis

Hinge Joint Hinge Joint

An example of a hinge joint is the elbow

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joint.

Hinge Joints Hinge Joints

• The knee joint

The knee joint

• In the knee joint the femur

articulates with the tibia.

• The patella (knee cap)

helps to give a better angle p g g

• f pull.
• The fibula is not part of the

knee joint and so the tibia is the weight bearing bone.

26-9 From: Essex

26-10 From: Mathis

• A ball-and-socket joint consists of a ball

A ball and socket joint consists of a ball (head) inserted into a socket. Movement is multiaxial allowing movement in almost multiaxial allowing movement in almost any direction

26-11 From: Hoxha

Ball-and-Socket joints Ball and Socket joints

• A spherical or hemispherical head of one

A spherical or hemispherical head of one bone articulates with a cuplike socket of another another

• Multiaxial joints permit the most freely

moving synovial joints moving synovial joints

26-12 From: Mathis

Ball-and-Socket Joint Ball and Socket Joint

An example of a ball-and-socket joint is the hip joint.

26-13 From: IPRO

Ball & socket joints Ball & socket joints

• The hip joint

p j

• The head of the femur fits into a

deep cavity called the t b l th l i b acetabulum on the pelvic bone.

• This deep cavity gives the hip

joint stability. joint stability.

• The presence of strong

ligaments add to the stability ki it diffi lt t di l t th making it difficult to dislocate the hip.

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26-15 From: Mathis

Hip Joint ROM Hip Joint ROM

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Knee Joint ROM Knee Joint ROM

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Angular movements Angular movements

• Angular movements involve changing the

Angular movements involve changing the angle between two parts of the body

• Found in most of all our limb joints
• Found in most of all our limb joints

26-18 From: Hoxha

Flexion / Extension Flexion / Extension

• Flexion means to bend (decrease the

Flexion means to bend (decrease the angle)

• Extension means to straighten (increase
• Extension means to straighten (increase

the angle)

26-19 From: Hoxha

26-20 From: Hoxha