Transition from shod to barefoot alters dynamic stability during running

Area of Science:

• Biomechanics
• Human Movement Science
• Sports Medicine

Background:

• Barefoot running is increasingly popular, but its effects on injury risk and performance remain debated.
• Studies often focus on kinetic and kinematic changes, with less attention to intrinsic stability.
• Local dynamic stability offers insights into neuromuscular control during transitions between running conditions.

Purpose of the Study:

• To investigate local dynamic stability during the immediate transition from shod to barefoot running.
• To identify biomechanical mechanisms underlying this transition.

Main Methods:

• Twenty healthy, habitually shod participants ran on a treadmill, alternating between shod and barefoot conditions.
• Largest Lyapunov exponents were calculated to assess movement control.
• Biomechanical parameters including cadence, flight time, contact time, vertical displacement, vertical impulse, and strike index were measured.

Main Results:

• Local dynamic stability significantly decreased during barefoot running, signifying worse movement control.
• Participants exhibited higher cadence and flight time, lower contact time, reduced vertical displacement and impulse.
• A significant shift towards a forefoot strike pattern was observed.

Conclusions:

• Immediate transition to barefoot running leads to increased instability and reduced movement control.
• This instability is associated with biomechanical changes, particularly altered foot strike patterns.
• The observed decrease in stability may have implications for injury risk and running performance.