Deck 7: Measurement and Analysis Techniques

Question 1

Dynamic calibration is necessary prior to data collection to ensure that

A) the participant is appropriately warmed up prior to performing the task
B) the position of each camera is known relative to the other cameras in the system
C) the origin of the global coordinate system is set appropriately
D) the optoelectronic system is capable of recording the desired movement
E) the optoelectronic system is time synchronised with other systems (e.g. force platforms)

Answer 1

B
Explanation: Dynamic calibration serves to provide essential information for determining the position of each camera relative to all others in the system.

Question 2

Prior to data collection, the calibrated area should be

A) of about the same size as would be required to perform the desired movement
B) of a smaller size than would be required to perform the desired movement
C) either larger or smaller than would be required to perform the desired movement
D) of a larger size than would be required to perform the desired movement
E) of no interest to the researcher, as calibration is only a formality

Answer 2

D
Explanation: To ensure that all data are accurately represented, the calibrated area should be larger than would be required for the desired movement to be performed.

Question 3

If a camera has field of view of 5 m, what diameter markers would be recommended for use?

A) 15 mm
B) 30 mm
C) 25 mm
D) 10 mm
E) 5 mm

Answer 3

C
Explanation: As a general rule, one should choose a marker that covers about 1/200th of the camera's field of view. As such, a field of view of 5 m (i.e. 5000 mm) would require a marker diameter of around 25 mm.

Question 4

Which of the following outcomes could not be assessed using a 3D optoelectronic motion analysis system alone?

A) Knee flexion and extension angle
B) Hip joint moment
C) Linear velocity of the foot segment
D) Trunk flexion angle
E) Step length during walking

Question 5

Which of the following is not true of a 'passive' 3D optoelectronic motion analysis systems?

A) They require at least 2 cameras to reconstruct the 3D position of markers
B) They can be integrated with other equipment, such as force platforms
C) They incorporate cameras that are capable of capturing data at high-speeds
D) They comprise cameras that emit infra-red light
E) They utilise joint markers that actively emit infrared light that is registered by the cameras

Question 6

Reconstruction of 3D marker locations can be achieved using

A) Fourier transformation
B) Direct Linear Transformation
C) Pythagoras' Theorem
D) Calculus
E) Hooke's law

Question 7

Major disadvantages of optoelectronic motion analysis systems are that they

A) Require all markers to be visible
B) Are not easily transported
C) Emit light that distracts participants
D) Are grossly inaccurate in their measurements
E) Cannot be synchronised with other equipment, such as force platforms

Question 8

Given optoelectronic motion analysis systems rely on light to identify markers, which of the following have the potential to influence these systems?

A) Dimly lit laboratories
B) Vibrant clothing
C) Sunlight
D) Highly-polished surfaces or metals
E) Barometric pressure

Question 9

The cameras used in common optoelectronic motion analysis systems rely upon sonar to identify markers

Question 10

The purpose of static calibration is to set the origin of the global coordinate system

Question 11

Active optoelectronic motion analysis systems rely on the joint markers to reflect infrared light

Question 12

Briefly describe the difference(s) between passive and active optoelectronic motion analysis systems

Question 13

Provide 3 examples of sporting activities that could be assessed using the marker set depicted in Figure G2.4

Question 14

Briefly describe the dynamic and static calibration processes and outline their respective purposes

Question 15

During the install of a new optoelectronic motion analysis system, you describe to the technician that you are planning to assess the performance of long jumpers. On the basis of the information that you've provided, he recommends that you use joint markers that have a diameter of 30 mm. Given this information, calculate the size of the cameras' fields of view?

Question 16

The law that states "the net force required to deform a spring from its equilibrium position is proportional to the extent of the deformation and the stiffness of the spring" is

A) Newton's Law of Inertia
B) Bernoulli's principle
C) Gauss' Law
D) Hooke's Law
E) Newton's Law of Gravitation

Question 17

The process via which data from multiple sensor types is combined is known as

A) Sensor mapping
B) Calculus
C) Sensor fusion
D) Trigonometry
E) Data fusion

Question 18

Sensors that can measure angular velocity are known as

A) Gyroscopes
B) Magnetometers
C) Barometers
D) Electrogoniometers
E) Accelerometers

Question 19

Which of the following forces are experienced by a system that is rotating

A) Centrifugal
B) Coriolis
C) Centripetal
D) A and B only
E) A, B and C

Question 20

Inertial measurement units are sophisticated devices that incorporate

A) Gyroscopes
B) Electrogoniometers
C) A sphygmomanometer
D) Accelerometers
E) A barometer

Question 21

A person is sitting in the centre of a platform that is rotating counter-clockwise. If they roll a ball toward a hole cut into its upper surface without allowing for the platform's rotation, the ball would

A) Fall short of the hole
B) Miss to the right
C) Overshoot the hole
D) Go in the hole
E) Miss to the left

Question 22

When a vibrating structure gyroscope is rotating clockwise, the inner frame will move to the right relative to the fixed housing of the circuit board

Question 23

The combination of Newton's Law of Acceleration and Hooke's Law reveals that the change in a spring's length is proportional to the acceleration of the system.

Question 24

Using the example of rolling a ball on a rotating platform, describe (in your own words), why the ball's trajectory is curvilinear in nature

Question 25

An elite marathon runner is returning from a recurrent bout of lower limb injuries and has been offered sponsorship from two competing footwear companies. Both companies offer a similar monetary package and will provide the runner with all of the equipment that he requires for his training and competition. His training for an upcoming event has been good, but his history of lower limb injury is always on his mind. He has completed long training runs in both prospective sponsors' shoes, but wants to be sure that he makes the right decision from an injury prevention point of view. You have been asked to assess the athlete while running on three separate occasions (each 2 weeks apart) to collect information that the athlete can use to help make his decision. To guide your advice, you have placed accelerometers on the lower leg (shank). Given the following data, outline which sponsor you would advise the athlete to go with and explain your choice from the perspective of injury risk.
Average peak vertical accelerations of the lower limb during the stance phase of running (in units of 'g')

Question 26

A free body diagram, for example of an athlete during the stance phase of running, includes:

A) All of the forces acting on the body and those produced by the body (i.e. acting on another body)
B) Only the forces acting on the body
C) A maximum of two forces
D) No forces
E) Only the forces produced by the body (i.e. acting on another body)

Question 27

Which of the following cannot directly be obtained from the dimensions of a force plate, the output from its transducers and/or the mass of the participant on the plate?

A) Location of the centre of pressure
B) Free moment
C) Acceleration of the centre of mass
D) Ground reaction force
E) Joint reaction force

Question 28

Following further processing, which of the following cannot be analysed using information gained from a force platform?

A) Pressure distribution underneath the foot
B) Angular momentum about an axis through the centre of mass
C) Shock absorption
D) Balance capability
E) Kinematics of the mass centre

Question 29

If a 85 kg adult was standing on one leg and the surface area under their foot was 0.017 m², how many kilopascals of pressure would they be exerting on the ground?

A) 49050 kPa
B) 5000 kPa
C) 14.175 kPa
D) 49.050 kPa
E) 14175 kPa

Question 30

At a pressure of 1.182 Atmospheres, what would be the pressure in millimetres of Mercury (mmHG) at zero degrees celcius (0°C)?

A) 898.3 mmHg
B) 788.2 mmHg
C) 634.6 mmHg
D) 912.7 mmHg
E) 643.0 mmHg

Question 31

Assuming a pressure of 4.24 Atmospheres and a temperature of zero degrees Celcius (0°C), which of the following pressure values is the odd one out?

A) 3222.4 mmHg
B) 522144 N/m²
C) 429.618 kPa
D) 429618 N/m²
E) None of these values

Question 32

If an object that has a contact area of 0.05 m² creates a pressure of 34.570 kPa, what is its mass in kilograms?

A) 183.1 kg
B) 120.4 kg
C) 145.8 kg
D) 176.2 kg
E) 152.9 kg

Question 33

A brick that has a mass of 3.5 kg exerts a pressure of 4.905 kPa on the ground. What is the size of the brick's contact area?

A) 0.007 m²
B) 0.08 m²
C) 0.004 m²
D) 0.01 m²
E) 0.7 m²

Question 34

An 80 kg athlete is standing with his weight evenly distributed over 0.013 m² contact area under each foot. What is the pressure under one of his feet?

A) 30.185 kPa
B) 10.202 kPa
C) 30184.6 N/m²
D) 60.369 kPa
E) 60369.2 N/m²

Question 35

A force of 1200 N exerted over a contact area of 0.03 m² would be more likely to cause an injury than a force of 800 N exerted over a contact area of 0.018 m²

Question 36

A pressure of 78.256 kPa is equivalent to a pressure of 0.772 Atmospheres

Question 37

Provide an example of a piece of sporting equipment that would be designed to have an increased surface area and explain why this design is important

Question 38

Briefly define what the units of 'Atmospheres' represents.

Question 39

Briefly explain the principle behind the design of a manometer.

Question 40

An athlete is performing bench press and his hands are equally sharing the combined weight of the bar and plates. If the combined contact area of the two hands is 0.02 m² and the pressure exerted on the hands is 53.955 kPa, what is the mass of the bar and plates in kilograms?

Question 41

A 75 kg female powerlifter is performing a back squat with a bar and weights totalling 130 kg. The combined weight of her body, the bar and the weight plates is equally distributed over both feet. If the sum of the pressures under the left and right feet is 167.588 kPa, what is the size of the contact area under the feet?

Question 42

The detected signal resulting from the depolarisation wave as it propagates in both directions along a single muscle fibre from its motor end plate is referred to as the:

A) Muscle fibre action potential (MAP)
B) Motor unit action potential (MUAP)
C) Motor unit action potential train (MUAPT)
D) Interference pattern
E) Raw electromyogram (raw EMG)

Question 43

The biceps brachii contains approximately 600 000 muscle fibres distributed between 750 motor units. What is the innervation ratio of the muscle?

A) 599250
B) 0.00125
C) 6750
D) 800
E) 600750

Question 44

Which is usually the highest amplitude of the electromyographical signal recorded at the skin surface (i.e. before amplification)

A) 5 microvolts (µV)
B) 50 microvolts (µV)
C) 500 microvolts (µV)
D) 5 millivolts (mV)
E) 50 millivolts (mV)

Question 45

Why are two electrodes usually used to record the electromyographic signal at the skin surface?

A) In case the signal from one of the electrodes is lost
B) Because the amplifier subtracts the signal from one electrode from the other, thus removing noise from the recorded signal
C) To record the signal from a greater number of motor units
D) To reduce the effect of cross-talk
E) To reduce skin resistance

Question 46

An electromyogram recorded using two 10 mm x 1 mm bar electrodes may contain signals from approximately how many motor units (MUs)?

A) Between 5 and 10 MUs
B) Between 20 and 50 MUs
C) Between 1000 and 2000 MUs
D) All of the MUs contained within the muscle of interest
E) Just the single MU directly beneath the electrodes

Question 47

When a raw EMG is processed to derive the Average Rectified EMG value (ARV), the length of the time window over which the signal is 'averaged' should be?

A) Specified by the investigator
B) Always equal to 100 ms
C) Always less than 100 ms
D) Always more than 100 ms
E) The default processing software option

Question 48

When a raw EMG is processed to derive the Average Rectified EMG value (ARV), what effect does increasing the length of the time window over which the signal is 'averaged' (e.g. from 50 ms to 100 ms) have on the final processed EMG?

A) It creates a rectified EMG
B) It has no effect
C) It creates a normalised EMG
D) It creates a noisier processed EMG, similar to the rectified EMG
E) It creates a smoother processed EMG, further removed from the rectified EMG

Question 49

Which of the heads of the triceps could electrical activity not reliably be recorded from using surface electromyography?

A) Lateral head
B) Medial head
C) Long head
D) Dead head
E) Short head

Question 50

Normalising EMGs is often performed by:

A) Dividing the EMG amplitude from the task by the EMG amplitude from the same muscle recorded during a maximal voluntary contraction.
B) Multiplying the EMG amplitude from the task by the EMG amplitude from the same muscle recorded during a maximal voluntary contraction.
C) Dividing the EMG amplitude from the task by the EMG amplitude from an antagonist muscle recorded a maximal voluntary contraction.
D) Dividing the EMG amplitude from the task by the EMG amplitude from the same muscle recorded during a sub-maximal voluntary contraction)
E) Multiplying the EMG amplitude from the task by the EMG amplitude from the same muscle recorded during a sub-maximal voluntary contraction.

Question 51

The main purpose of normalising EMGs is to allow comparison with those from other muscles and/or people:

Question 52

The term isokinetic means

A) Testing while no movement of the lever arm takes place
B) Testing against a constant or pre-selected variable resistance
C) Testing where the rate of the movement is held at a constant pre-determined angular velocity
D) Testing where the rate of movement and the resistance is held constant
E) All of these

Question 53

The term isometric means

A) Testing where the rate of the movement is held at a constant pre-determined angular velocity
B) Testing while no movement of the lever arm takes place
C) Testing where the rate of movement and the resistance is held constant
D) Testing against a constant or pre-selected variable resistance
E) None of these

Question 54

The term Isotonic means

A) Testing where the rate of movement and the resistance is held constant
B) Testing against a constant or pre-selected variable resistance
C) Testing where the rate of the movement is held at a constant pre-determined angular velocity
D) Testing while no movement of the lever arm takes place
E) Testing where the movement, the velocity and the resistance are held constant

Question 55

An isokinetic dynamometer is used to

A) Test the muscles that support joints
B) Assess the effectiveness of a strength training program
C) Improve the strength of muscles
D) Exercise and rehabilitate patients following injury
E) All of these

Question 56

Isometric or static testing is a situation when the muscle develops tension and the fibres shorten but no movement of the lever arm takes place

Question 57

Full extension of the leg is where the leg is bent to a 90° angle

Question 58

Isokinetic testing is when the limb is tested under a variable speed situation

Question 59

An isokinetic dynamometer is a device that can test a limb in an isokinetic, isometric and isotonic mode

Question 60

It is usual to see true isokinetic dynamometers in the fitness centre or gymnasium

Question 61

Name some of the commercial companies that make isokinetic dynamometers

Question 62

Name some of the joints of the body that can be tested using an isokinetic dynamometer

Question 63

What is an agonist muscle?

Question 64

Name some of the variables that an Isokinetic dynamometer can measure?

Question 65

What is/are important consideration(s) for performance in track cycling?

A) The aerodynamics of the bike
B) The position of the rider on the bike
C) The UCI rules
D) The aerodynamics of the rider
E) All of these

Question 66

What is the current world record for the 4000 m individual track pursuit in cycling?

A) 4 min 10.534 seconds
B) 4 min 20.9 seconds
C) 4 mins 19 seconds
D) 4 mins 11.114 seconds
E) none of these

Question 67

Which of these are technological advancements that are characteristic of a bike that is used in competition?

A) Extended aerobars
B) Steep seat angled frames
C) Aerodynamic frames
D) Solid spoke-less wheels
E) All of these

Question 68

Early tennis rackets were made from?

A) Titanium
B) Aluminium
C) Wood
D) Fibre-glass
E) None of these

Question 69

Large headed tennis rackets were designed to help the player do what?

A) Hit more shots precisely
B) provide more power to the ball
C) reduce injury
D) allow them to be swung faster
E) All of these

Question 70

Increasing the speed of the racket towards the ball by 33% has the potential to increase ball speed by what %?

A) 0
B) 0.25
C) 0.05
D) 0.31
E) 0.33

Question 71

Changes to Triathlon bikes were the forerunners to modified track bike designs

Question 72

The current world record holder for the 4000 m individual track pursuit is Chris Boardman

Question 73

The Union Cycliste Internationale is the official body for rules and regulations in competitive cycling

Question 74

Increasing the racket mass in tennis is more important for ball speed than increasing the speed of the racket towards the ball.

Question 75

Today, it is possible to use a tennis racket that will measure the number and type of shots that you make in a game or match.

Question 76

The service in tennis is one of the most important parts of the game.

Question 77

Why do you think that the individual track pursuit world record in cycling has not changed since 2011?

Question 78

Do you think that we are currently at a position in competitive cycling where we are judging who has the best technology rather than who is the best athlete?

Question 79

What would you consider the most technological advancement that can have a significant affect in competitive cycling?

Question 80

What is one of the most effective ways to execute a flat serve in tennis?