Foot segment kinematics during normal walking using a multisegment model of the foot and ankle complex

Area of Science:

• Biomechanics
• Orthopaedics
• Human Movement Science

Background:

• Gait analysis with optical tracking is clinically valuable for 3D human body kinematics and kinetics.
• Current methods treat the foot as a single rigid segment, limiting measurement of internal foot joint motion.
• This limitation hinders accurate assessment for foot and ankle conditions.

Purpose of the Study:

• To develop and validate a multisegment kinematic model of the foot for gait analysis.
• To enable measurement of motion within the foot's joints, overcoming limitations of rigid-body models.
• To enhance the clinical utility of gait analysis in orthopaedic and rehabilitative contexts.

Main Methods:

• A multisegment foot model was created, dividing the foot into hindfoot, talus, midfoot, and medial/lateral forefoot segments.
• Six functional joints were defined, including ankle, subtalar, hindfoot motions, forefoot twist, and arch height.
• Twelve asymptomatic subjects underwent barefoot walking trials using a six-camera optical stereometric system.

Main Results:

• The model demonstrated repeatability for ankle, subtalar, and forefoot motions.
• Hindfoot motions exhibited lower repeatability within and between subjects.
• Foot pronation correlated with medial longitudinal arch drop during stance, with arch recovery during late stance and swing.

Conclusions:

• The developed multisegment foot model successfully measures internal foot motion, addressing a key limitation in current gait analysis.
• These detailed measurements are essential for maintaining the relevance of gait analysis in foot and ankle treatment.
• The model provides crucial data for improved orthopaedic and rehabilitative strategies for the foot and ankle.