Week 7

Question 1

How do we measure ground reaction force (GRFs)

Answer 1

Force plates

Question 2

What directions can force plates measure

Answer 2

Forces in:
Vertical
Anterior-posterior
Medial lateral

Question 3

What is the most commonly analysed ground reaction force

Answer 3

Vertical

Question 4

Force equals

Answer 4

Mass x Acceleration

Question 5

What is impact peak

Answer 5

The force of the landing limb rapidly decelerating and colliding with the ground

Question 6

What is active peak

Answer 6

The force resulting from the motion of the rest of the body accelerating over the ground

Question 7

Which GRF parameters may be related to injury risk in runners

Answer 7

Loading rate

Impact Peak

Question 8

Medically diagnosed injures in female runners saw to have ______ compared to normal female runners

Answer 8

Greater Vertical Impact peak

Greater Vertical average loading rate

Greater Vertical Instantaneous loading rate

Question 9

Those that have stress fractures in lower extremities have _________ compared to normal runners

Answer 9

Greater average loading rates

Greater Instantaneous vertical loading rates

Question 10

Rearfoot runners graphs possess

Answer 10

Impact peak

Active peak

Loading rate between initial contact and impact peak

Question 11

Forefoot runners graphs possess

Answer 11

Hidden impact peak

Active peak

Loading rate between initial contact and active peak

Question 12

Difference between rearfoot strike and forefoot strike is

Answer 12

Rearfoot strike has an impact peak visible

Question 13

The loading rate will be higher in rearfoot or forefoot

Why

Answer 13

Rearfoot

The curve is steeper

Question 14

Forefoot striking has

Answer 14

Lower laoding rate

No impact peak

Question 15

Conclusion from research article states that forefoot running overall

Answer 15

There is fewer running related injuries than those running rearfoot strike

Question 16

What % of people usually run rearfoot

What % of people usually run forefoot

Answer 16

95%

5-10%

Question 17

The active peaks in rearfoot and forefoot running are

Answer 17

About the same

Question 18

What is different with regards to impact peak of forefoot running

Answer 18

The force of impact occurs later during a forefoot strike

This impact force may be hidden within the active force

There is still one there, just cant see it

Question 19

Forefoot running related to injuries

Answer 19

No evidence it reduces running injury rates

May decrease the risk of sustaining certain injuries such as knee injuries

May increase the risk of sustaining certain injuries such as Calf/ankle/foot injuries

Question 20

What knee injuries can forefoot running reduce the risk in

Answer 20

Patellofemoral pain

IT band syndrome

Patellar teninopathy

Tibial stress fractures

Question 21

What Calf/ankle/foot injuries can forefoot runner cause

Answer 21

Calf strains

Achilles tendinopathy

Metatarsal stress fracture

Question 22

How do shoes affect foot strike and vertical ground reaction forces

Answer 22

Minimalist shoes increased both the vertical impact peak and average vertical landing rate

Question 23

What other factors other than shoes could affect foot strike

Answer 23

Speed of running plays a factor

Question 24

What happens to forefoot striking

Answer 24

Impact peak gone (usually)

Lower loading rate

Question 25

What happens to rearfoot

Answer 25

Impact peak higher Loading rate higher

Question 26

Loading rate consists of

Answer 26

The middle 60% of initial slope Average loading rate = slop Instantaneous loading rate = peak slop

Question 27

What is the highest vertical ground reaction force of the impact peak slop

Answer 27

Highest VGRF point (peak)

Question 28

What is the highest VGRF after impact peak or highest overall if no impact peak

Answer 28

Active peak

Question 29

What axis do we use to find vertical ground reaction force

Answer 29

Z axis

Question 30

What do we use to calculate impact peak What do we use to calculate propulsive peak

Answer 30

Highest VGRF of first peak Highest VGRF of the second peak

Question 31

How do we calculate propulsive peak

Answer 31

Highest VGRF of the second peak

Question 32

What usually causes people to transition to forefoot strike

Answer 32

Sprinting or increasing speed

Question 33

Force plates measure forces in which direction(s)

Answer 33

Medial/lateral Anterior/posterior Vertical

Question 34

The force that results from the rapid deceleration of the leg while striking the ground is represented by which aspect of the vertical ground reaction force curve

Answer 34

Impact Peak

Question 35

Lower loading rates have been associated with a higher risk of injury

Answer 35

False

Question 36

Forefoot striking generally results in no visible impact peak when looking at the ground reaction force curve

Answer 36

True

Question 37

Forefoot striking definitively lowers the risk of developing an injury

Answer 37

False

Question 38

Which statement about the impact force during running is true

Answer 38

There is still an impact force in forefoot running, it just occurs later during stance phase and is hidden by the active force

Question 39

When running in minimal shoe or barefoot, which statement is false

Answer 39

If a runner maintains a rearfoot strike, the loading rate will generally be lower

Question 40

The average loading rate is calculated with what portion of the vertical ground reaction force curve

Answer 40

The middle 60% of the region from initial foot strike to the first vGRF peak

Question 41

The vertical ground reaction force curve for walking also generally has two peaks

Answer 41

True

Question 42

The impact peak will never be higher in magnitude than the active peak

Answer 42

False