Controllable Factors 2

Question 1

Criteria for selecting running shoes

Answer 1

• Performance
• Protection
• Comfort
• Durability
• Weight
• Price
• Taste/Fashion

Question 2

Essential characteristics of a running shoe

Answer 2

• Attenuation of single/multiple impact forces
• Preservation of foot stability
• Adequate friction/traction
• Provision of different footstrike type
• Heat dissipation
• Comfort

Question 3

Structural parts of a running shoe

Answer 3

-Insole = contributes to reduction of impact forces, perspiration, absorption and comfort
-Heel counter = provides rear-foot stability, claimed to prevent excessive pronation
Inserts = Reduce impact, increase rear foot stability

Question 4

Running shoes and impact attenuation

Answer 4

• Impact forces related to injury (Achilles bursitis) 500-1200 impacts/km
• Impact force variables (peak vertical force, time to peak vertical force, peak loading rate, time to peak loading rate.
• Running shoes provide the runner with only 1% energy of the total energy required per running stride. Stored energy cannot be returned at the correct time, point, frequency.

Question 5

Running shoes and rearfoot control

Answer 5

Materials should be softer - lateral and denser - medial in order to achieve rear-foot control as well as impact attenuation
A reduction of flare can decrease joint pronation.

Question 6

Barefoot Running, why is it beneficial?

Answer 6

The forefoot landing technique is beneficial in running due to the increased reliance on SSC.
BUT
many recreational runners are physically unprepared for this activity of the muscle-tendon unit.

Question 7

What is compliance?

Answer 7

Compliance is the opposite of stiffness

• low compliance = high risk of injury
• high compliance = low performance

Question 8

What is resilience?

Answer 8

Amount of energy returned as a percentage of the amount of energy absorbed at impact.
-Examples 
Soccer 20-45%
Cricket 20-34%
Tennis grass 42%
Tennis Synthetic 60%

Question 9

What is hardness?

Answer 9

Resistance to penetration

Hard = stiff, soft = compliant

Question 10

What is impact attenuation?

Answer 10

Measurement of the reduction of impact forces

% of reduction of the max impact force on a surface (x) compared with that generated on concrete

Question 11

What are the characteristics of natural surfaces?

Answer 11

Surface absorbs energy and returns little - can be detrimental to those who can rely to a greater extent on lower limb muscle elasticity
Great impact attenuation, good resilience
Increases energy expenditure - reduction in muscle elasticity energy potentiation

Question 12

Artificial Surfaces, what are the characteristics?

Answer 12

High resilience. Good traction. Stiff (hard) - low compliance (increased injury risk)
Non-compliant surfaces: higher impacts
Artificial surfaces resist rotation