Injury and shoe surface design

Question 1

What are the two different types of athletic injury?

Answer 1

Acute - Traumatic event

Chronic - Overuse injuries resulting from repetitive action

Question 2

List intrinsic factors causing injury.

Answer 2

Age
Sex
Previous injury
Aerobic fitness
Muscle strength
Reaction time
Anatomical alignment
Postural stability

Question 3

List extrinsic factors causing injury.

Answer 3

Footware
Surface
Competition level

Question 4

Name and explain the two joints in the ankle.

Answer 4

Talocrural joint - Between distal tibia/fibia and proximal talus. Hinge joint. Allows sagittal plane motion.
Subtalar joint - Below talus. Allows frontal and transverse plane motion

Question 5

What are the three characteristics of supination?

Answer 5

Inversion
Adduction
Plantar-flexion

Question 6

What are the three characteristics of Pronation?

Answer 6

Eversion
Abduction
Dorsi-flexion

Question 7

Describe the rearfoot movement during the different stages of the footstrike.

Answer 7

Heelstrike - Supination
Foot stance - Pronation
Midstance - Neutral
Toe-off - Supination

Question 8

What are the characteristics of pronation and supination?

Answer 8

Pronation - Suggested to contribute to cushioning of impact and allows adaptation to the surface. Linked with internal tibial rotation.
Supination - Linked with external tibial rotation

Question 9

Highlight the findings relating to rearfoot movement and injury.

Answer 9

Hreljac (2000) - Lower velocity of pronation in runners with previous injury compared with uninjured
Duffy (2000) - Runners with anterior knee pain had lower pronation on first 10% of stance
Pohl (2009) - No difference in peak rearfoot eversion between those with plantar fasciitis and controls
Stefanyshyn (2001) - There was a reduced injury rate as eversion and eversion velocity increased
Messier (2018) - Rearfoot motion variables not associated with injury.

Question 10

What is plantar fascia?

Answer 10

Thick connective tissue that connects tuberosity of calcaneus with metatarsal heads

Question 11

What were the typical peak eversion angles during running?

Answer 11

Willems (2005) - 4 degrees

Pohl (2009) - 11 degrees

Question 12

Highlight the findings regarding inversion and injury.

Answer 12

Willems (2005) - Maximum inversion velocity was later in injury group, so they spent more time in pronation
Rice (2014) - Narrower bimalleolar breadth was associated with risk of injury.

Question 13

What characteristics are highlighted in shoe advertisment?

Answer 13

Shock absorption/cushioning 
Motion control/stability
Traction
Weight
Comfort

Question 14

What is shoe stability?

Answer 14

The ability of the shoe to resist excessive motion of the ankle. Qunatified by measuring rearfoot motion.

Question 15

What is the impact of a heel flare on shoes?

Answer 15

Large heel flare prevents rolling.

Increased medial heel flare reduces rear foot movement

Question 16

What is the impact of a reduced lateral heel flare?

Answer 16

Reduced initial pronation in first 10% of ground contact

Lower initial pronation velocity

Question 17

What is the impact of medial posting and dual density?

Answer 17

Reduces rear foot movement

Increases stability

Question 18

Highlight the findings on orthotic devices.

Answer 18

Reduce rear foot movement
Make foot more neutral
Increase comfort
Reduce lower limb movement
Mundermann (2003) - Reduce peak eversion and eversion velocity
Nigg (1998) - No influence on movement or eversion characteristics
Gross (1991) - Orthotics helps 75% of runners, remaining 25% showed worse symptoms, no change or picked up an injury from the orthotic

Question 19

What is the impact of shoe surface cushioning?

Why is shoe surface cushioning important?

Answer 19

Reduces impact force characteristics.
Reduces loading rates.
High impact force characteristics have been linked with injury risk.

Question 20

Describe the characteristics of barefoot running.

Answer 20

Mid or fore foot strike is preferential
Foot is presented flatter to the groud to compensate for the higher impact at the heel
Reduced rearfoot movement
Increased calf activation
No/minimal cushioning

Question 21

Why may shoes have different coefficients of friction? (give a sporting example)

Answer 21

Tennis shoes have a different coefficient of friction based on the surface they are designed for.

Question 22

Describe how football boots have evolved.

Answer 22

They have become lighter to accommodate increased performance
They must be low profile and have high traction
Bently (2010) - Blades increase plantar pressure and injury risk
Muller (2010) - Boots produce high traction due to high ankle moments