Shoe heel-toe drop affects running economy.

Area of Science:

• Biomechanics
• Exercise Physiology
• Sports Footwear Technology

Background:

• Optimizing running economy is crucial for distance runners aiming to improve performance.
• Shoe design, particularly heel-toe drop, is a potential factor influencing metabolic cost during running.

Purpose of the Study:

• To investigate the effect of varying shoe heel-toe drop on metabolic energy expenditure during running.
• To analyze the biomechanical responses associated with different heel-toe drop levels.

Main Methods:

• Twenty runners ran at a consistent speed (3.5 m/s) using custom footwear with four heel-toe drop conditions (0, 10, 20, 30 mm).
• Metabolic energy expenditure, vertical ground reaction forces, and joint kinematics/kinetics were measured.
• Muscle fascicle lengths and joint moments were analyzed.

Main Results:

• Increasing heel-toe drop significantly increased net metabolic power during running.
• Higher heel-toe drop reduced vertical ground reaction forces but increased ankle effective mechanical advantage.
• Elevated heel-toe drop led to increased ankle plantarflexion and shorter medial gastrocnemius fascicle lengths, alongside increased knee moments.

Conclusions:

• Lower heel-toe drop shoes, particularly zero drop, promote more economical running by optimizing muscle operating lengths and reducing knee extensor moments.
• Distance runners seeking to enhance speed should consider zero heel-toe drop footwear based on these metabolic and biomechanical findings.