Shoe drop has opposite influence on running pattern when running overground or on a treadmill

Area of Science:

• Biomechanics of running
• Sports footwear technology
• Human locomotion analysis

Background:

• Minimalist running shoes aim to promote a forefoot strike by reducing sole height difference (drop).
• Previous research compared barefoot and shod running, but the specific effects of minimalist shoe drop are less understood.
• Understanding how shoe drop influences running mechanics across different surfaces is crucial for injury prevention and performance.

Purpose of the Study:

• To investigate whether the effect of shoe drop on running mechanics is consistent between overground and treadmill running.
• To determine the influence of varying shoe drop (0, 4, 8 mm) and barefoot conditions on running biomechanics.

Main Methods:

• Twelve healthy males participated, running barefoot and in shoes with 0, 4, and 8 mm drop.
• Data collection included vertical ground reaction forces (vGRF) and lower limb kinematics (foot, ankle, knee flexion).
• Running trials were conducted on both a treadmill and overground to compare task-specific effects.

Main Results:

• Loading rates showed opposing trends between overground and treadmill running based on footwear drop.
• Barefoot running exhibited higher loading rates overground but lower rates on the treadmill compared to the highest drop shoe.
• Ankle and knee flexion at touchdown were greater during treadmill running, except in barefoot conditions where no difference was observed.

Conclusions:

• Shoe drop is a significant factor altering running patterns, with its effects on vGRF varying between treadmill and overground conditions.
• The consistent kinematic response of barefoot running across tasks, unlike shod conditions, explains differing conclusions between running modalities.
• Running shoe design, particularly sole drop, requires careful consideration of the intended running environment (treadmill vs. overground).