Structure and function of joints

• A&P
• Higher Education (non-degree)

ANATOMY AND PHYSIOLOGY FOR SPORTS MASSAGE 

THE STRUCTURE AND FUNCTION OF THE SKELETAL SYSTEM

ANATOMY AND PHYSIOLOGY FOR SPORTS MASSAGE

THE STRUCTURE AND FUNCTION OF JOINTS

What are you going to learn?

In this lesson you're going to learn to . . .

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Describe the different type of joints.  

Explain the structure of synovial joints

Describe the joint actions at major joints.  

Explain the characteristics of ligaments and tendons. 

4

STRUCTURE & FUNCTION OF JOINTS 

Fibrous Joints

These are classed are immovable joints with no movement between bone. Held together by a thin layer of string connective tissue. 

Examples include:

• Cranium 
• Pelvis 

Cartilaginous Joints

Classed are slightly moveable joints where bones are attached to each other by fibrocartilage or fibro-cartilaginous discs. 

Examples include:

• Between vertebrae
• Pubic symphysis 

There are three main joint classifications these include: 

Synovial Joints

These joints are classed as freely moveable joints allowing a free range of movement (ROM) between articulating surfaces. 

Types include:

• Gliding - Shoulder girdle
• Hinge - Eblow and knee
• Pivot - Elbow 
• Ball and Socket = Shoulder and hip 
• Saddle - Thumb 
• Condyloid - Ankle and wrist

STRUCTURE & FUNCTION OF JOINTS 

Synovial Joints

Synovial Joints. Synovial joints are characterized by the presence of an articular capsule between the two joined bones. 

Bone surfaces at synovial joints are protected by a coating of articular cartilage. 

Synovial joints are often supported and reinforced by surrounding ligaments, which limit movement to prevent injury. 

There are six types of synovial joints,

STRUCTURE & FUNCTION OF JOINTS 

Pivot joints

Provide rotation. At the top of the spine, the atlas and axis form a pivot joint that allows for rotation of the head.

Ball-and-socket joints

Are a freely moving joint that can rotate on any axis. The hip and shoulder joints are examples of ball and socket joints.

Condyloid joint 

Allow for circular motion, flexion, and extension. The wrist joint between the radius and the carpal bones is an example of a condyloid joint.

Saddle joints

Allow for flexion, extension, and other movements, but no rotation. In the hand, the thumb’s saddle joint (between the first metacarpal and the trapezium) lets the thumb cross over the palm, making it opposable.

Hinge joints 

Move on just one axis. These joints allow for flexion and extension. Major hinge joints include the elbow and finger joints.

Gliding joints 

Move against each other on a single plane. Major gliding joints include the intervertebral joints and the bones of the wrists and ankles.

STRUCTURE & FUNCTION OF JOINTS 

Typical structure of a synovial joint 

Articular cartilage

Articular / hyaline cartilage- connective tissue covering the end of bones to reduce friction. 

Joint capsule

Fibrous joint capsule- stabilises the joint containing synovial fluid.

Synovial membrane

Synovial membrane- lining the fbrous capsule which secretes synovial fluid into the synovial cavity in response to movement. 

Ligaments

Ligaments- bone are attached together by strong and tough ligaments helping to prevent dislocation. 

Bursae

Bursae- small fluid sacs located around major joints between bone and tendons and/or muscles around a joint. Helping to reduce friction between tendons and bone.

Synovial fluid

Synovial fluid- is a thick liquid located between your joints. The fluid cushions the ends of bones and reduces friction when you move your joints.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Flexion - Refers to movement where the angle between two bones decreases. Flexion is commonly known as bending.  

Extension - Refers to movement where the angle between two bones increases. Extension is otherwise known as straightening.  

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Horizontal Flexion - Refers to movement where the angle between two bones decreases and on the horizontal plane.

Horizontal Extension - Refers to movement where the angle between two bones increases and occurs on the horizontal plane.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Lateral Flexion - Refers to movement of the spine laterally away from the midline of the body. This can be seen when we bend to one side.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Abduction - Is movement of a body segment away from the midline of the body.

Adduction - Is movement of a body segment toward the midline of the body.

Circumduction - This is a movement where the joint is the pivot and the body segment moves in a combination of flexion, extension, adduction and abduction.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Protraction - This is forward movement of the scapula that results in ‘hunching’ of the shoulders.

Retraction - This is backward movement of the scapula as they pull together to ‘square’ the shoulders and push the chest out.

Elevation - Refers to the raising of the scapula to a more superior level (shrugging the shoulders). 

Depression - Refers to the scapula moving to a more inferior position as they are pulled downwards.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Supination - movement so the palm of the hand faces upward or forward (anteriorly).

Pronation - movement so the palm of the hand faces downward or backward (posteriorly).

 

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Eversion - Is the movement of the foot to bring the sole of the foot to face outward.

Inversion - Is the movement of the foot to bring the sole of the foot to face inward.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Rotation - Refers to a pivoting or ‘twisting’ movement. Rotation is broken down further into medial and lateral rotation.

Medial rotation - The movement of a body segment where the front (anterior) of the segment rotates medially (inwards) towards the midline of the body.

Lateral rotation - The movement of a body segment where the front (anterior) of the segment rotates laterally (outwards) away from the midline of the body.

STRUCTURE & FUNCTION OF JOINTS 

Joint action at major joints

Match up the descriptions to the joint actions  

Protraction 

Adduction

Lateral flexion 

where the angle between two bones increases

Refers to a pivoting or ‘twisting’ movement

when we bend to one side

where the angle between two bones decreases

 to bring the sole of the foot to face inward.

to bring the sole of the foot to face outward.

movement of a body segment toward the midline of the body

hunching’ of the shoulders

Match up the descriptions to the joint actions  

Horizontal flexion

Elevation 

Retraction 

Pronation

Supination

Depression 

Abduction

a combination of flexion, extension, adduction and abduction

Raising of the scapula to a more superior level 

Movement of a segment away from midline

the angle between two bones decreases and on the horizontal plane

 movement so the palm of the hand faces upward or forward

scapula moving to a more inferior position 

movement so the palm  faces downward or backward (posteriorly).

backward movement of the scapula

STRUCTURE & FUNCTION OF JOINTS 

JOINT	JOINT TYPE	JOINT ACTION
Cranium / Spine (atlas/axis)	Pivot	Rotation
Spine (vertebrae)	Gliding	Flexion, extension, lateral flexion and rotation
Shoulder joint (humerus/scapula)	Ball and Socket	Flexion, extension, horizontal flexion and extension, adduction, abduction, medial and lateral rotation, circumduction
Shoulder girdle (sternum/clavicle/scapula)	Gliding	Elevation, depression, protraction, retraction
Elbow (humerus/ulna)	Hinge	Flexion and extension
Elbow (radius/ulna)	Pivot	Pronation and Supination
Wrist (carpal)	Condyloid	Flexion, extension, adduction and abduction

Match the joint to the joint type and action 

Pivot - Pronation and Supination

Condyloid - Flexion, extension, adduction and abduction

Ball and Socket- Flexion, extension, horizontal flexion and extension, adduction, abduction, medial and lateral rotation

Pivot - Rotation

Gliding - Flexion, extension, lateral flexion and rotation

Hinge - Flexion, extension

Gliding - Elevation, depression, protraction, retraction 

Cranium / Spine

Elbow

(humerus/ulna)

Spine (vertebrae)

Shoulder girdle

Wrist (carpal)

Elbow

(radius/ulna)

Shoulder joint 

STRUCTURE & FUNCTION OF JOINTS 

JOINT	JOINT TYPE	JOINT ACTION
Thumb	Saddle	Flexion, extension, adduction and abduction
Fingers (phalanges)	Hinge	Flexion, extension
Hip (pelvis/femur)	Ball and Socket	Flexion, extension, horizontal flexion and extension, adduction, abduction, medial and lateral rotation, circumduction.
Knee (femur/tibia)	Hinge	Flexion and extension, slight rotation
Ankle (tibia/talus)	Hinge	Flexion and extension
Ankle (talus/calcaneus)	Condyloid	Inversion and eversion
Toes (phalanges)	Hinge	Flexion, extension

A saddle joint providing flexion, extension, abduction and adduction joint action?

1. Wrist
2. Fingers
3. Elbow
4. Thumb

The hip reffered to a ball and socket joint provides ______________ joint action.

1. Flexion and extension
2. Horizontal flexion and extension
3. Adduction and abduction,
4. Flexion, extension, horizontal flexion and extension, adduction, abduction, medial and lateral rotation

The Hinge joint of the knee also offers slight rotation

1. True
2. False

The Ankle (talus/calcaneus) joint providing inversion and eversion action is what type of joint?

1. Saddle
2. Hinge
3. Condyloid
4. Pivot

What joint action do the phalanges provide?

1. Flexion / extension
2. Adduction / abduction
3. Circumduction
4. Rotation

The hinge joint of the ankle providing flexion and extension is provided from what two articulating bones?

1. Tibia / Talus
2. Fibula / Talus
3. Talus / Calcaneus
4. Tibia / Calcaneus

STRUCTURE & FUNCTION OF JOINTS 

Ligaments

Structure

Band of tough, fibrous dense connective tissue made of collagen

Function

Connects bone to bone and stabilises joint and prevent unwanted movement. Lengthened ligaments will result in a less stable joint. 

Properties

Avascular (Poor blood supply)

Non-elastic (may lengthen under stress)

Non-contractile (but may shorten through disuse)

STRUCTURE & FUNCTION OF JOINTS 

Tendons

Structure

Band of tough, fibrous dense connective tissue contained within a sheath

Function

Connects muscle to bone.

Properties

Avascular (poor blood supply)

Primary non-elastic- however the achilles tendon may as a spring mechanism storing energy.

Non-contractile (but may shorten through disuse). 

Match up the characteristics to ligaments or tendons 

Ligaments

Tendons

Contained within a sheath

Connects muscle to bone 

Made of collagen

Avascular

Non-elastic- Except of Achilles

Non-contractile

 Connects bone to bone

Can act as a spring like mechanism

Avascular

Non-elastic

Non-contractile

Stabilises joint and prevent unwanted movement

What you have learnt

Following this lesson you should now be able to . . .

1

2

3

Describe the different type of joints.  

Explain the structure of synovial joints

Describe the joint actions at major joints.  

Explain the characteristics of ligaments and tendons. 

4

Well done! Great job, you have now completed this lesson. 

Next up...The structure and function of muscular system.