Changes in windlass effect in response to different shoe and insole designs during walking

Area of Science:

• Biomechanics
• Orthopedics
• Sports Medicine

Background:

• The windlass effect, crucial in gait, involves peak plantar aponeurosis strain during pre-swing.
• Increased dorsiflexion of the 1st metatarsophalangeal (MTP) joint is a primary driver of the windlass effect.
• Understanding footwear's impact on the windlass effect is vital for managing foot disorders like plantar fasciitis.

Purpose of the Study:

• To evaluate how different shoe and insole combinations influence the windlass effect.
• To identify footwear that effectively reduces the windlass effect during gait.

Main Methods:

• Kinematic analysis of 10 healthy volunteers during gait.
• Testing barefoot, standard shoes (SS) with flat (FI) or carbon fiber insoles (CFI), and rocker sole shoes (RSS) with FI or CFI.
• Utilized a transparent polymer shoe cover for precise marker placement and kinematic data acquisition.

Main Results:

• Barefoot 1st MTP dorsiflexion averaged 48.0°.
• Standard shoes reduced this to 28.2° (SS/FI) and 24.1° (SS/CFI).
• Rocker sole shoes dramatically decreased dorsiflexion to ~13° (RSS/FI and RSS/CFI), irrespective of insole type.

Conclusions:

• Rocker sole shoes are highly effective in mitigating the windlass effect.
• Footwear choice, particularly rocker soles, can significantly alter foot biomechanics.
• Findings support the use of rocker sole shoes in managing conditions aggravated by the windlass effect, such as plantar fasciitis.