Principles of Movement

Question 1

Where does most human movement analysis occur?

Answer 1

A lab setting with high levels of variable control

Question 2

Any movement in the sagittal plane occurs around which axis?

Answer 2

Frontal axis

Question 3

Any movement in the transverse plane occurs around which axis?

Answer 3

Vertical / Longitudinal axis

Question 4

Any movement in the frontal plane occurs around which axis?

Answer 4

Sagittal axis

Question 5

What is Centre of Mass (COM)?

Answer 5

The average position of mass of an object

Question 6

What is Centre of Gravity (COG)?

Answer 6

The point in an abject where gravity appears to be acting

Question 7

What is the difference between COM and COG in relation to clinical movement analysis?

Answer 7

They are interchangable, the only way they would change significantly is if you went really high up a mountain

Question 8

In the standard anatomical position, where is the COM?

Answer 8

Roughly the area of S2, near the bellybutton

Question 9

What is the line of gravity?

Answer 9

A vertical line from the centre of gravity to the ground or surface the object or person is on

Question 10

What affect does bending sideways have on both the COM and line of gravity?

Answer 10

The COM stays the same whereas the line of gravity moves sideways

Question 11

What happens when the line of gravity leaves the base of support?

Answer 11

We become unstable

Question 12

What are the three types of forces?

Answer 12

Gravitational (Weight)
Applied (Contact)
Inertial (Motion)

Question 13

Force is a vector quantity, what does this mean?

Answer 13

It has both magnitude and direction

Question 14

What unit is used to measure force?

Answer 14

Newtons (N)

Question 15

On a diagram, how is force represented?

Answer 15

As a proportional arrow demonstrating both magnitude and direction

Question 16

What is meant by the term load?

Answer 16

The force exerted on a surface or body

Question 17

What is Newton’s First Law?

Answer 17

A body remains in the same state of motion unless acted on by an unbalanced force

Question 18

According to Newton’s First Law what must happen to a body in order to for it to move?

Answer 18

An unbalanced force must act on it as a balanced force would cause it to remain in motion

Question 19

What is ground reaction force (GRF)?

Answer 19

The force exerted by the ground on a body in contact with it

Question 20

Rearrange Newton’s Second Law to find Acceleration, explain how this is relevant in relation to moving weight:

Answer 20

Acceleration = Force / Mass (a=F/m),

Meaning a heavier object will require more force to cause the same acceleration as an object of a smaller mass

Question 21

What is Newton’s Second Law?

Answer 21

Force = Mass x Acceleration (F=ma)

Question 22

According to Newton’s First Law, if a body is at rest and the forces acting on it are balanced, what will happen?

Answer 22

The body will remain at rest

Question 23

Which of Newton’s Laws is being applied here?

“If A exerts a force on B, then B will exert an equal yet opposite force on A”

Answer 23

Newton’s Third Law,

Every action has an equal and opposite reaction

Question 24

According to Newton’s First Law, if a body is moving and the forces acting on it are balanced, what will happen?

Answer 24

It will keep moving at a constant speed in a straight line

Question 25

What is Newton's Third Law?

Answer 25

For every action there is an equal and opposite reaction

Question 26

What is a lever?

Answer 26

A body segment which rotates around a fulcrum (joint axis)

Question 27

What produces rotation of a body segment around an axis?

Answer 27

An unbalanced force (most likely generated by internal muscle contraction)

Question 28

What unit is used to measure a moment?

Answer 28

Newton Meters (NM)

Question 29

What is moment?

Answer 29

The turning effect which a force has around a fulcrum dependent upon the size of the force and the distance of moment arm

Question 30

Calculate the moment for this example: | A force of 40N is applied at 50cm from the axis of rotation:

Answer 30

``` Moment = Force x Distance Moment = 40 N x 0.5 M Moment = 20NM ```

Question 31

What is the equation for moment?

Answer 31

Moment = Force x Distance

Question 32

What is meant by the moment arm?

Answer 32

The perpendicular distance between the application of force and the fulcrum of movement

Question 33

If a weightlifter is squatting 100ks, what is this force in Newtons?

Answer 33

1000 N

Question 34

What is meant by resultant force?

Answer 34

The sum of forces acting in multiple directions causing a final effect

Question 35

What is a collinear force system?

Answer 35

When lines of action of all the forces of a system are operating on the same line or >-->

Question 36

Tension is most likely caused by what type of force system?

Answer 36

Collinear when each side is being pulled away on the same line

Question 37

What is a co-planar force system?

Answer 37

When the lines of action of a set of forces lie in a single plane

Question 38

A sled push is an example of which force system?

Answer 38

Collinear

Question 39

The trapezius muscle is an example of which force system?

Answer 39

Concurrent

Question 40

The erector spinae and iliopsoas work together as a pelvic control anteriorly and posteriorly, what force system is this?

Answer 40

Co-planar

Question 41

What is a concurrent force system?

Answer 41

Where all forces act on the same point

Question 42

A scrum is an example of which force system?

Answer 42

Collinear

Question 43

A seesaw is an example of which force system?

Answer 43

Co-planar

Question 44

A tug of war is an example of which force system?

Answer 44

Collinear

Question 45

What is a first order / class lever?

Answer 45

Where the fulcrum is located between the resistance and effort

Question 46

What is a second order / class lever?

Answer 46

Where the resistance is located between the fulcrum and effort

Question 47

What is a third order / class lever?

Answer 47

Where the effort is located between the fulcrum and resistance

Question 48

What lever order is demonstrated through the hip abductors levelling the pelvis during gait? Give the Fulcrum, Resistance and Effort:

Answer 48

1st Class, fulcrum in middle Fulcrum = hip joint line Resistance = weight on other side of body Effort = TFL / Glut Med / Glut Min pulling down

Question 49

What lever order is demonstrated through the calf muscle when taking a step? Give the Fulcrum, Resistance and Effort:

Answer 49

2nd Class, resistance in middle Fulcrum = Metatarsals Resistance = Weight of the body slightly behind metatarsals Effort = Gastrocnemius

Question 50

How can you remember the order of lever classes?

Answer 50

1, 2, 3 | F, R, E

Question 51

What are most lever orders in the body?

Answer 51

3rd Class

Question 52

What lever order is demonstrated through the arm lifting a weight (curl)? Give the Fulcrum, Resistance and Effort:

Answer 52

3rd Class, effort in middle Fulcrum = Elbow joint Resistance = The weight in the hand Effort = Biceps

Question 53

What mechanical advantage is gained from a longer lever arm?

Answer 53

A larger moment can be generated for a given force

Question 54

What is the resistance arm?

Answer 54

The distance between load and fulcrum

Question 55

What is the effort arm?

Answer 55

The distance between effort and fulcrum

Question 56

What does it mean to have a mechanical advantage of 1?

Answer 56

There will be no advantage (or disadvantage)

Question 57

What does it mean to have a mechanical advantage of >1?

Answer 57

There is a force advantage and larger objects can be moved with less effort