5.4 (f1): Factors Affecting Movement

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5.4 (f1) Factors Affecting Movement

• 1. Joints
• 2. Muscles
• 3. Ligaments/Tendons

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1. Joints

• a. Classification Of Joints
• b. Types Of Joint
• c. Movements At Joints
• d. Types Of Movement

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a. Classification Of Joints

• There are 3 types of joints in the body
• 1. Immovable Joints
• 2. Slightly Movable Joints
• 3. Freely Movable (Synovial) Joints

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1. Immovable Joints
These are fixed joints. No movement is possible
between the bones. Examples are found between the
flat bones of the skull that fuse to form the
cranium. (see above)
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2. Slightly Movable Joints
The bones are linked by cartilage. Slight
movement is possible between the bones. Examples
are found in the joints of the vertebral column.
(see above)
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3. Freely Moveable Joints (Synovial Joints)
Synovial joints are complex joints where the
bones are linked by ligaments. A wide variety of
movement is possible. There are a number of
different types of synovial joints throughout the
body. (see above)
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b. Types Of Joint
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Ball And Socket Joint

• 1. Moves freely in all directions.
• 2. Ligaments are often used to keep the joint
  stable.
• 3. Examples shoulder and hip. (see opposite)

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Pivot Joint

• 1. Only rotation is possible because it has a
  ring on a peg, structure.
• 2. Example between the atlas and axis vertebrae
  in the neck. (see opposite)

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Hinge Joint

• 1. Movement in one plane only.
• 2. Will open until it is straight.
• 3. Movement is limited because of the shape of
  the bones and the position of the ligaments.
• 4. Example elbow. (see opposite)

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Condyloid Joint

• 1. Movement is possible in two planes.
• 2. The rounded end of one bone fits in to the
  hollow of another.
• 3. Movement is back and forward and
  side-to-side.
• 4. Ligaments prevent rotation.
• 5. Example wrist (see opposite)

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Saddle Joint

• 1. Allows movement in two planes at right angles
  to each other.
• 2. Movement is back and forward and side top
  side.
• 3. Movement is limited because of the shape of
  the bones.
• 4. Example thumb. (see opposite)

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Types Of Movements At Joints
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Extension

• Our limbs straighten at a joint.
• For example jumping.

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Flexion

• Our limbs bend at a joint.
• For example bringing foot back to kick.

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Abduction

• Our limbs are moved away from a line down the
  middle of the body.
• For example the box splits. (legs sideways)

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Adduction

• Our limbs are moved towards a line down the
  middle of the body.
• For example crucifix to straight shape on
  rings.

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Rotation

• This is a circular movement. Part of the body
  turns whilst the rest remains still.
• For example a golf swing.

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Circumduction

• The end of a bone moves in a circle.
• For example A tennis serve.

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2. Muscles

• a. Classification Of Muscles
• b. Names Of Major Muscles/Muscle Groups
• c. Antagonistic Muscle Action/3rd Order
  Levers
• d. Types Of Muscle Fibre
• e. Types Of Muscular Contraction

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a. Classification Of Muscles

• There are 3 types of muscle in the body
• 1. Cardiac Muscle
• 2. Smooth (Involuntary) Muscle
• 3. Skeletal (Voluntary) Muscle

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1. Cardiac Muscle

• This is a very specialised type of involuntary
  muscle found only in the heart.
• It contracts regularly, continuously and without
  tiring.
• It works automatically but is under constant
  nervous and chemical control.

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2. Smooth Or Involuntary Muscle

• These muscles work automatically.
• They are not under our conscious control.
• They work our internal organs such as the
  stomach, gut and bladder.

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3. Skeletal Or Voluntary Muscle

• These muscles work as we instruct them.
• They are under our control.
• They make our bodies move.
• We use them for everyday and sporting activities
  such as walking, running and jumping.

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b. Major Muscles Of The Body
Trapezius
Deltoid
Triceps
Pectoralis Major
Biceps
Abdominals
Latissimus Dorsi
Quadraceps
Hamstrings
Gastrocnemius
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c. Antagonistic Muscle Action

• 1. Our muscles can pull by contracting but they
  CANNOT push.
• 2. If one muscle contracts across a joint to
  move two bones together, another muscle is needed
  to pull the bones apart. Eg, biceps and triceps
  are needed to bend the arm at the elbow. (see
  next slide)
• 3. We need a large number of pairs of muscles to
  work in different ways for even simple body
  movements.

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Muscles take on different roles depending on the
movement we are performing. They can work as

1. Flexors contracting to bend our joints. Eg
   biceps.
2. Extensors contracting to straighten our joints.
   Eg triceps.
3. Prime Movers (Agonists) contracting to start a
   movement.
4. Antagonists relaxing to allow a movement to take
   place.
5. Fixators contracting to steady parts of the body
   to give the working muscles a firm base.
6. Synergists reducing unnecessary movement when a
   prime mover contracts. They also fine tune our
   movement.

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Muscle Action Needed To Bend Arm At Elbow
Biceps act as the Prime Mover, contracting to
start the movement. They are also acting as
Flexors.
Triceps act as Antagonists, relaxing to allow the
movement.
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How Third Order Levers Cause Movement
W
E
F
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d. Types Of Muscle Fibre

• Slow Twitch (Red) Fibres
• Have very good oxygen supply.
• Work for a long time without tiring.
• Are not as strong as fast twitch fibres.
• Take longer to contract.
• Are used in all types of exercise.
• Are especially suited to aerobic activities.

• Fast Twitch (White) Fibres
• Have a very poor oxygen supply.
• Work for a short time as they tire very quickly.
• Are stronger than slow twitch fibres.
• Contract very quickly.
• Are only used in high intensity exercise.
• Are especially suited to anaerobic activities.

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Types Of Muscular Contraction
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1. Isotonic And Concentric Contraction

• Muscles shorten as they contract.
• The ends of the muscle move closer together.
• Most sporting movements are of this type.
• Eg our bicep when doing a bicep curl. (see
  diagram)

Muscle Shortening
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2. Isotonic And Eccentric Contraction

• Muscles lengthen as they contract.
• The ends of the muscle move further apart.
• Plyometric exercises involve contractions of this
  type.
• Eg our bicep when punching. (see diagram)

Muscle Lengthening
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3. Isometric Contraction

• Muscles stay the same length as they contract.
• There is no movement so the ends of the muscle
  stay the same distance apart.
• In many movements, the stabilising muscles hold
  parts of the body steady as other parts move.
• Eg Shoulder muscles during a tug-of-war.

No Movement
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3. Ligaments/Tendons

• Ligaments
• These are bands of tough fibrous tissue.
• These come in different shapes and sizes.
• They hold bones together at joints.
• They limit our range of movement.
• They prevent dislocation.
• They will stretch to a limited amount.

• Tendons
• These are strong, flexible cords at the end of
  muscles.
• They attach muscles to bones.
• These come in different shapes and sizes.
• Some muscles end in two or more different tendons
  which may be fixed to different bones.