Temporal couplings between rearfoot-shank complex and hip joint during walking

Area of Science:

• Biomechanics
• Human Movement Analysis
• Musculoskeletal Dynamics

Background:

• Common assumption: rearfoot pronation-supination and hip internal-external rotation are temporally coupled.
• This coupling is foundational to many proposed musculoskeletal injury mechanisms.
• Previous research yielded conflicting evidence on this foot-hip interdependence.

Purpose of the Study:

• To investigate the temporal coupling between rearfoot motion and hip rotation during walking.
• To analyze the relationship between rearfoot-shank complex motion and hip transverse plane motion.

Main Methods:

• Three-dimensional lower extremity kinematics were measured in 18 healthy subjects during walking.
• Cross-correlation and Pearson correlation analyses were used to assess temporal similarities and peak timing relationships.
• Motion analysis focused on rearfoot-shank transverse and frontal plane motion and hip transverse plane motion.

Main Results:

• Strong temporal coupling observed between shank internal-external rotation and hip internal-external rotation (mean r=0.77).
• Moderate temporal coupling found between rearfoot eversion-inversion and hip internal-external rotation (mean r=0.56).
• Significant relationships noted between peak rearfoot eversion timing and peak hip internal rotation timing (r=0.62).

Conclusions:

• Findings support a temporal coupling between rearfoot pronation and hip internal rotation, and supination with hip external rotation.
• Individual variability in coupling strength necessitates personalized clinical evaluation.
• This foot-hip coupling has implications for understanding gait mechanics and injury prevention.