W7 & 8 - Sports Shoes & Surfaces

Question 1

List shoe characteristics highlighted in advertising

Answer 1

Shock absorption/Cushioning

Motion control/stability (kinematics)

Traction (kinematics)

Weight/energy

Comfort/fit

Question 2

What is meant by shoe stability (motion control)?

Answer 2

Ability of the shoe to resist excessive or unwanted motion of the ankle.

Question 3

How is shoe stability (motion control) quantified?

Answer 3

By measuring rear foot motion.

Question 4

What comes under shoe design characteristics

Answer 4

Shoe shape (i.e medial + lateral heel flare)

Shoe supportive features

Orthotic devices (i.e wedging)

Question 5

What do studies show about the Biomechanical influence of Othotic devices?

Answer 5

Some show reductions in peak eversion or eversion velocity.

Others don’t.

Question 6

What do orthotic devices do?

Answer 6

Influence lower limb movement by ⬇️ peak eversion + eversion velocity

Question 7

What have orthotic devices helped?

Answer 7

75% of distance runners

Question 8

What design factors of a running shoe have been found to influence rear foot stability?

Answer 8

Heel flare

Material properties

Medial posting

Orthotic devices

Question 9

What are the 2 types of force plate that measure reaction force vs your foot?

Answer 9

Piezoelectric force plate

Strain gauge force plate

Question 10

What do FZ represent when talking about force plates?

Answer 10

Vertical ground reaction force.

Question 11

Evidence from Hatala et al. (2013) showed that, with increasing running speed, what happens to foot strike?

Answer 11

% of runners who demonstrated a midfoot/forefoot strike ⬆️

Question 12

What did Hamill et al. (2011) find when comparing barefoot and shod running?

Answer 12

Runners landed with a more plantar flexed ankle when barefoot

Question 13

When testing barefoot runners, which did Nunns et al (2012) report to be the most commonly observed footstrike type?

Answer 13

Heel strike

Question 14

Lieberman et al (2010) suggest that heel strike is caused by which aspects of modern running shoes?

Answer 14

Raised heel

Question 15

In the paper by Lieberman et al (2010), what aspect of a forefoot/midfoot strike was suggested to reduce injury risk?

Answer 15

Lack of a clear impact peak

Question 16

Which of the following was a major strength of the study by Altman and Davis (2015), assessing injury in shod and barefoot runners?

Answer 16

Prospective study

Question 17

How much shoe mass increases oxygen consumption by 1%?

Answer 17

100g

Question 18

How much is it estimated that speed decreases, with a 1% increase in oxygen consumption?

Answer 18

3m/min

Question 19

What did Professor Daniel Lieberman publish in 2010?

Answer 19

Paper suggesting that barefoot running can ⬇️ ones predisposition to chronic running related injuries

Also that running w/ modern 21st century trainers w/ cushioning etc… has led us to change our natural way of running set out by evolution + that now the new way due to trainers impact is what actually causes our injuries.

That trainers encourage us to run w/ heelstrike.
In Kenya (barefoot running) theres more running w/ a forefoot strike.

Question 20

Quotes from Professor Daniel Lieberman from his 2010 paper

Answer 20

“Habitually barefoot endurance runners often land on the fore-foot before bringing down the heel”

“Habitually shod runners mostly rear-foot strike”.

Question 21

What is the impact peak?

Answer 21

1st peak visible after the point of touchdown.

Question 22

What does the slope of the line leading to impact peak represent?

Answer 22

Vertical loading rate.

Question 23

Results to Hatala et al (2013)

Daasanach group in Northern Kenya

Answer 23

77% used rear foot strike

% of mid foot + fore-foot strikes ⬆️ w/ speed.

Impact loading was ⬇️ w/ forefoot strike.

Question 24

Ruder et al (2019)

Answer 24

Rearfoot striker + mid foot striker exp higher tibial shock than FFS.

RFS + MSF ⬆️ TS w/ speed.

FFS do NOT.

Question 25

Ruder et al (2019)

Answer 25

Rearfoot striker + mid foot striker exp higher tibial shock than FFS.

RFS + MSF ⬆️ TS w/ speed.

FFS do NOT.

Question 26

What is the active peak?

Answer 26

2nd peak on the vertical ground reaction force trace.

Question 27

What is the active peak associated with?

Answer 27

Propelling the athlete towards their next step.

Question 28

Are impacting peaks/loading rates higher in shoes?

Answer 28

According to De Wit et al. (2000)

• Greater impact loading rate in barefoot vs shod.
• Barefoot landed w/ a flatter foot.
• Runners ran both shod + barefoot w/ a RFS.

Question 29

Are impact peaks higher in shoes?

Answer 29

Hamill et al (2011)

• Red. impact loading rate in barefoot vs shod.
• Barefoot landed w/ a plantar flexed angle.
• Shod landed w/ a dorsi flexed angle.
• MFS adopted when barefoot.

Question 30

Influence of surface

Answer 30

Gruber et al (2013)

• 40 habitual RFS ran barefoot on soft + hard surface.
• • 80% has a RFS on soft.
• • 35% has a RFS on hard surface.

Question 31

Footwear, footstrike + loading rates

Answer 31

Rice at al (2016)

Peak instantaneous loading rates (ILR) lower when running in minimal shoes w/ a FFS than standard shoes w/ either RFS to FFS.

Question 32

Do high loading rates = injury?

Answer 32

Plantar fascians group has higher peak in loading rate (vertical) compared to control group.

(Poke, Hamill + Davis, 2009)

Question 33

Shoe design characteristics

What can a reduced lateral heel flare result in?

Answer 33

⬇️ leverage = ⬇️ moment causing rotation

Question 34

Shoe design characteristics

What can be the result of medial posting + high density in a trainer?

Answer 34

⬇️ rear foot movement

Question 35

What does cushioning in shoes do?

Answer 35

⬇️ impacts compared to barefoot.

Loading rates are also shown to ⬇️ as cushioning ⬆️.