Module One, Lecture Ten

Question 1

How does the Skeletal Muscle cause movement at Synovial Joints? ( 4 )

Answer 1

1. Attaches to bone ( lever )
2. Muscle structure ( Length, number of fibres, arrangement of fibres )
3. Type of contraction ( Roles / Action )
4. Where it crosses a join ( Location )

Question 2

What are the three Classes of Levers? ( 3 )

Answer 2

1. First ( Stabilises joint position )
2. Second ( Effective at overcoming heavy loads )
3. Third ( Large range of movement )

Question 3

Example of First Class Lever…

Answer 3

See-Saw or Scissors ( Fulcrum between force and load )

Question 4

Example of Second Class Lever…

Answer 4

Wheelbarrow or Bottle Opener ( Load between fulcrum and force

Question 5

Example of Third Class Lever…

Answer 5

Tweezers or Fishing Rod ( Force between fulcrum and load )

Question 6

What is the Fulcrum?

Answer 6

The point on which a lever rests and pivots

Question 7

How does Muscle Form determine Function? ( 3 )

Answer 7

Depends on…

1. Length of muscle fibres
2. Number of muscle fibres
3. Arrangement of muscle fibres

Question 8

How does the Length of Muscle Fibres determine function?

Answer 8

If a large ROM is required = long muscle fibres

Question 9

How does the Number of Muscle Fibres determine function? ( 2 )

Answer 9

1. Tension is directly proportional to the cross-sectional area
2. Greater number of fibres ( greater CSA and greater tension )

Question 10

How are Muscles Fibres Arranged? ( 2 )

Answer 10

1. Paralle
2. Pennate

Question 11

Describe the structure of Parallel Muscle Fibres…

Answer 11

Fibres arranged vertically between muscle tendons / attachments

Question 12

Describe the structure of Pennate Muscle Fibres…

Answer 12

Fibres arranged obliquely between muscle tendons / attachments

Question 13

What are the three ways a muscle can contract? ( 3 )

Answer 13

1. Concentric
2. Eccentric
3. Isometric

Question 14

What is Concentric Muscle Contraction?

Answer 14

Muscle is action and develops tension, which is greater than the load. The muscle shortens and there is a change in joint position ( e.g. Elbow Flexion )

Question 15

What is Eccentric Muscle Contraction?

Answer 15

Muscle is active and develops tension, which is lesser than the load. The muscle elongates in opposite direction and there is a change in joint position ( E.g Elbow Extension )

Question 16

What is Isometric Muscle Contraction?

Answer 16

Muscle is active and develops tension, which does not outweigh the load. There is no change in length of muscle or joint position ( e.g Holding the elbow join still, biceps brachii contracts isometrically )

Question 17

What are the Types of Muscle Roles? ( 4 )

Answer 17

1. Agonist ( Creates movement )
2. Antagonist ( Opposes / controls movement )
3. Stabiliser ( holds joints still )
4. Neutraliser ( stops unwanted movement )

Question 18

What are the Concentric Actions of Muscles? ( 4 )

Answer 18

1. Medial + Adduction
2. Anterior + Flexion
3. Lateral + Abduction
4. Posterior + Extension

Applies for all joints except for the knee