The effect of ambient temperature on the shoe-surface interface release coefficient

Area of Science:

• Sports Engineering
• Biomechanics
• Materials Science

Background:

• Previous research linked football shoe performance to cleat design and turf conditions.
• The influence of temperature on the shoe-turf interface, particularly rotational resistance, remained less understood.

Purpose of the Study:

• To investigate the effect of varying temperatures on the rotational torsion resistance of artificial turf football shoes.
• To assess the safety implications of temperature-dependent shoe-surface interactions for athletes.

Main Methods:

• Five distinct football shoe models were tested on dry Astro Turf across a temperature range of 52°F to 110°F.
• An assay device with a prosthetic foot measured the force required to release shoes from the turf surface.
• A torque wrench applied rotational force to simulate pivoting, with release coefficients recorded.

Main Results:

• Significant differences in release coefficients were observed across shoe models and temperatures.
• Increased turf temperature, combined with specific cleat designs, altered shoe-surface friction.
• A correlation was found between laboratory findings and clinical injury data.

Conclusions:

• Turf temperature is a critical factor influencing the shoe-surface interface and potential for athlete injury.
• Only flat-soled basketball-style turf shoes met safety criteria across all tested temperatures.
• Cleat characteristics and temperature interact to affect friction, posing risks to knee and ankle joints.