Week 7 Flashcards
How do we measure ground reaction force (GRFs)
Force plates
What directions can force plates measure
Forces in:
Vertical
Anterior-posterior
Medial lateral
What is the most commonly analysed ground reaction force
Vertical
Force equals
Mass x Acceleration
What is impact peak
The force of the landing limb rapidly decelerating and colliding with the ground
What is active peak
The force resulting from the motion of the rest of the body accelerating over the ground
Which GRF parameters may be related to injury risk in runners
Loading rate
Impact Peak
Medically diagnosed injures in female runners saw to have ______ compared to normal female runners
Greater Vertical Impact peak
Greater Vertical average loading rate
Greater Vertical Instantaneous loading rate
Those that have stress fractures in lower extremities have _________ compared to normal runners
Greater average loading rates
Greater Instantaneous vertical loading rates
Rearfoot runners graphs possess
Impact peak
Active peak
Loading rate between initial contact and impact peak
Forefoot runners graphs possess
Hidden impact peak
Active peak
Loading rate between initial contact and active peak
Difference between rearfoot strike and forefoot strike is
Rearfoot strike has an impact peak visible
The loading rate will be higher in rearfoot or forefoot
Why
Rearfoot
The curve is steeper
Forefoot striking has
Lower laoding rate
No impact peak
Conclusion from research article states that forefoot running overall
There is fewer running related injuries than those running rearfoot strike
What % of people usually run rearfoot
What % of people usually run forefoot
95%
5-10%
The active peaks in rearfoot and forefoot running are
About the same
What is different with regards to impact peak of forefoot running
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
Forefoot running related to injuries
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
What knee injuries can forefoot running reduce the risk in
Patellofemoral pain
IT band syndrome
Patellar teninopathy
Tibial stress fractures
What Calf/ankle/foot injuries can forefoot runner cause
Calf strains
Achilles tendinopathy
Metatarsal stress fracture
How do shoes affect foot strike and vertical ground reaction forces
Minimalist shoes increased both the vertical impact peak and average vertical landing rate
What other factors other than shoes could affect foot strike
Speed of running plays a factor
What happens to forefoot striking
Impact peak gone (usually)
Lower loading rate
What happens to rearfoot
Impact peak higher
Loading rate higher
Loading rate consists of
The middle 60% of initial slope
Average loading rate = slop
Instantaneous loading rate = peak slop
What is the highest vertical ground reaction force of the impact peak slop
Highest VGRF point (peak)
What is the highest VGRF after impact peak or highest overall if no impact peak
Active peak
What axis do we use to find vertical ground reaction force
Z axis
What do we use to calculate impact peak
What do we use to calculate propulsive peak
Highest VGRF of first peak
Highest VGRF of the second peak
How do we calculate propulsive peak
Highest VGRF of the second peak
What usually causes people to transition to forefoot strike
Sprinting or increasing speed
Force plates measure forces in which direction(s)
Medial/lateral
Anterior/posterior
Vertical
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
Impact Peak
Lower loading rates have been associated with a higher risk of injury
False
Forefoot striking generally results in no visible impact peak when looking at the ground reaction force curve
True
Forefoot striking definitively lowers the risk of developing an injury
False
Which statement about the impact force during running is true
There is still an impact force in forefoot running, it just occurs later during stance phase and is hidden by the active force
When running in minimal shoe or barefoot, which statement is false
If a runner maintains a rearfoot strike, the loading rate will generally be lower
The average loading rate is calculated with what portion of the vertical ground reaction force curve
The middle 60% of the region from initial foot strike to the first vGRF peak
The vertical ground reaction force curve for walking also generally has two peaks
True
The impact peak will never be higher in magnitude than the active peak
False
