Quiz Questions Flashcards
EMG
Electromyography
In the quantitative analysis of running in AFL, what was one of the key findings?
There is a persistent imbalance between left and right legs.
Transverse plane
Divides top and bottom halves
Sagittal plane
Vertical, dividing left and right halves
Frontal plane
Divides front and back halves
Frontal axis
Sagittal plane
Longitudinal axis
Transverse plane
Sagittal axis
Frontal plane
Contribution of sports medicine to developing an athlete
Injury management
Contribution of physiology to developing an athlete
Fitness
Contribution of strength and conditioning to developing an athlete
Physical state
Contribution of psychology to developing an athlete
Mental state
Statics, in mechanical terms, is:
Mechanics of objects at rest or moving at constant velocity
Bar path and bar velocity are tied to body position during which 2 phases of the snatch?
First and second pull
As a bowler turns his arm over to bowl the ball, his arm is undergoing what motion?
Angular motion around the frontal axis
As a bowler runs towards the wicket prior to delivering he is undergoing what motion?
Linear motion in the sagittal plane
As a batsman steps forward before rotating to strike the ball his trunk is undergoing what type of motion?
Linear motion in the frontal plane
As a batsman plays the sweep shot to hit the ball, his trunk is undergoing what type of motion?
Angular motion about the longitudinal axis.
Ligaments are a ____ Body
Non-rigid
Muscles are a ____ body
Non-rigid
A cricket bat is a ____ body
Rigid
Bones are ____ bodies
Rigid
In a closed kinetic chain movement, the distal segments move…
Simultaneously with the proximal segments
What effect does body mass have on the relationship between minimalist shoes and risk of running injury?
Heavier runners have increased risk of injury when running in minimalist shoes
What is the definition of stride length?
The distance between consecutive foot-ground contacts of the same foot
What are the characteristics of minimalist footwear?
Lack of motion control devices
Low shoe mass
High flexibility
Low heel-toe drop
When compared to conventional shoes, what effect does running barefoot have on stride rate and stride length?
Increased stride rate
Decreased stride length
When compared to conventional shoes, what effect does running in minimalist shoes have on mechanical work at the knee and ankle?
Increased mechanical work at the ankle
Decreased mechanical work at the knee joint
Running in minimalist shoes is most likely to increase pain in which parts of the body?
Ankle, calf and shin
Good running economy is demonstrated by…
Using less energy at a given running velocity
When compared to conventional shoes, what effect does running barefoot have on knee and ankle joint angles at initial contact?
Increased knee flexion and ankle plantarflexion
What is the definition of ground reaction force?
A force that is equal in magnitude and opposite in direction to the force exerted by a body/object on the ground
Angular momentum
The magnitude of a system’s angular motion
Requires angular impulse to change it
A skier flying through the air wants to decrease forward rotation of their body. They should…
Rotate their arms forwards in large circles
Moment of inertia
Rotational inertia, the resistance of a body to change its rotary motion
What are the 4 properties of a torque?
Magnitude
Axis of rotation
Line of application
Point of application
The moment of inertia of the lower extremity around the hip joint is changed by knee flexion and extension, which alters what?
The radius of gyration
Regarding torque, clockwise motion is…
Negative (-ve)
Regarding torque, anticlockwise motion is…
Positive (+ve)
After determining the location and nature of the obstacle, the MIT ‘Cheetah’ then processes information to alter…
Step length and force required to clear the obstacle
As a runner runs, their centre of gravity oscillates and as such, the work done by the runner will…
Vary based on the vertical oscillations of the CoG.
Describe the forces of the front and rear feet in a sprinter off the starting blocks.
Front foot: concentric force in the sagittal plane
Rear foot: eccentric force in the frontal plane
Free body diagrams are characterised by:
Stick figure representation of rigid bodies and external forces acting on the system.
What are the unique properties of a force?
Magnitude
Direction
Line of action
Point of application
When the MIT ‘Cheetah’ lands on its front feet after clearing the hurdle this is an example of ____ equilibrium.
Unstable
According to the results of Adolph et al. (2012), what changes occur as we learn to walk?
- step length, width and per hour
- time walking
- distance covered
- no. falls
Step length increases Step width decreases Time walking increases Steps per hour increase Distance covered increases Falls decrease
An eccentric force causes a body to undergo…
Rotational motion
May also cause translation
How does the MIT Cheetah robot analyse its environment to plan its motions?
It uses a 2D laser distance sensor to get information about height and distance of the object.
What mechanical factors can be used to maximise stability?
What does this do to mobility?
Increase base of support, lower centre of gravity, position centre of gravity towards the expected external force within the base of support.
Decreases motility
A point of peak flexion in a squat is often referred to as the ___
Hole
The high-bar is ___ to the snatch and clean
Comparable
If an Olympic weightlifter squats 190kg (1RM), what could you predict their snatch 1RM will be?
106.4kg
What will typically occur if the CoP moves out of the BoS?
A loss of balance
The low-bar back-squat displays ___ forward lean than the high-bar back-squat?
Greater
A belt-less 1RM back-squat is typically __% of a belted back-squat 1RM.
90
Kinetics can be defined by forces that cause ____.
Motion
Kinematics can be defined as describing movement without ____.
Force
At what speed does a 1RM squat typically occur at?
0.2m/s
The ____ is often referred to as the ‘traditional’ squat.
High-bar
In Carol Putnam’s paper on segmental interaction, one of her conclusions is that the summation of speed ___ is a valid explanation of the sequential sequencing observed in walking, running and kicking, but the summation of ___ principle cannot be similarly explained.
Speed
Force
In de Hoyo et al (2016), what parameters did they find were more likely altered by the eccentric training on side-stepping performance?
Contact time and time spent braking.
A good observational strategy should include at least these 3 items:
What critical features to focus on
How to control the situation
Number of observations needed
What are the 4 components of a skill analysis?
Preparation
Observation
Evaluation
Intervention
Projectile motion applies to all bodies including humans. For performance purposes…
CoG cannot be altered once in flight, by applying internal forces to the limbs to change the distribution of mass with respect to the CoG.
When might 45 degrees not be the optimum release angle for maximum range?
A faster release speed may be possible at a lower or higher angle.
What is common to all projectile motion?
Gravity
To ensure maximum range when the release height is greater than the landing height…
…then the optimal angle of release is less than 45 degrees.
To ensure maximum range when the release height is less than the landing height…
…then the optimal angle of release is greater than 45 degrees.
To ensure maximum range when the release height is the same as the landing height…
…then the optimal release angle is 45 degrees.
In projectile motion, what does the height of release determine?
Trajectory shape (the difference between the height of initial projection to the height at which it lands or stops)
In projectile motion, what does the velocity of release determine?
The length or size of the projectile’s trajectory.
In projectile motion, what does the angle of release determine?
The shape of a projectile’s trajectory
Projectile motion is characterised by _____ horizontal velocity and _____ vertical velocity
Constant horizontal velocity
Changing vertical velocity
What factors determine the range of a projectile?
Horizontal velocity and time in the air
According to Blazevich (2012), to learn a skill that requires high speed and high accuracy, like a tennis serve, it is common to teach…
…the skill in a way that breaks the skill down to a push-like pattern and then progress to a throw-like pattern.
In Carol Putnam’s paper on segmental interaction, what was one of her conclusions?
That the summation of speed principle is a valid explanation of the sequential sequencing observed in walking, running and kicking, but the summation of force principle cannot be similarly explained.
