Multiscale Biomechanical Analysis of Running: Inter- and Intraindividual Variability with Insights into Second...

Area of Science:

• Biomechanics
• Sports Science
• Orthopedics

Background:

• Running variability influences biomechanical load distribution and injury risk.
• Understanding internal bone stress variability is crucial for injury prevention.

Purpose of the Study:

• Compare variability across biomechanical features at different analysis scales.
• Correlate biomechanical features with second metatarsal stress amplitude and variability.
• Explore inter- and intra-individual variability in second metatarsal stress distribution.

Main Methods:

• Eight participants ran for 30 minutes, with kinematics, kinetics, and plantar pressure recorded.
• A dynamic finite element foot model, driven by musculoskeletal modeling, estimated internal foot loads.
• Variability was quantified using mean standard deviation and compared across categories like ground reaction force (GRF), joint angles, and muscle forces.

Main Results:

• Ground reaction forces (GRF) showed the lowest variability; joint angles exhibited the highest.
• Second metatarsal stress amplitude correlated with vertical GRF, joint moments, and muscle forces.
• Stress variability showed inconsistent correlations and significant participant-dependent variations.

Conclusions:

• External biomechanical features (GRF, kinematics) inadequately represent internal load variability.
• Assessing internal stress/load variability requires more than just external running metrics.
• Participant-specific analysis is essential for understanding metatarsal stress variability.