The interrelationship between three-dimensional foot mobility and bodyweight bearing

Area of Science:

• Biomechanics
• Human Anatomy
• Orthopedics

Background:

• Understanding foot mobility under load is crucial for biomechanical analysis.
• Previous research has not fully elucidated the 3D interrelationships of foot structures during weight-bearing.

Purpose of the Study:

• To investigate the three-dimensional foot mobility and its internal coordination during bodyweight bearing.
• To quantify changes in foot morphology and joint angles between sitting and standing positions.

Main Methods:

• Collected 3D kinematic data of the foot in 31 healthy adults in sitting and standing postures.
• Utilized motion capture with retroreflective markers placed on specific anatomical landmarks.
• Analyzed changes in foot length, width, and joint angles (e.g., calcaneus eversion, hallux valgus).

Main Results:

• Significant increases in foot length, heel width, forefoot width, hallux valgus angle, and calcaneus eversion angle when standing versus sitting.
• Significant decrease in the digitus minimus varus angle when standing.
• Medial and inferior displacement of malleoli, navicular, and foot dorsum; anterior displacement of other foot indices.
• Correlations identified between calcaneus eversion and medial/inferior displacements, indicating coordinated intra-foot movement.

Conclusions:

• Bodyweight significantly influences foot morphology and mobility, altering dimensions and joint alignments.
• Established clear interrelationships between different foot structures during weight-bearing, clarifying intra-foot coordination.
• Findings provide valuable insights for biomechanical modeling, footwear design, and clinical assessment of foot function.