Increase in foot arch asymmetry after full marathon completion

Area of Science:

• Biomechanics
• Sports Medicine
• Podiatry

Background:

• Long-distance running is known to reduce the medial longitudinal arch (MLA) of the foot.
• The effect of marathon running on the symmetry of foot arch reduction between the left and right feet remains unclear.
• Understanding foot arch changes and asymmetry is crucial for injury prevention in runners.

Purpose of the Study:

• To investigate whether foot arch asymmetry increases after completing a full marathon.
• To identify factors influencing the degree of navicular height and navicular height displacement asymmetry.
• To quantify changes in navicular height and arch height ratio post-marathon.

Main Methods:

• Collected 3D foot posture data from 74 collegiate runners using an optical foot scanner.
• Measurements were taken before (PRE) and immediately after (POST) a full marathon.
• Analyzed navicular height, arch height ratio, and asymmetry indices using statistical methods, including multiple linear regression.

Main Results:

• Both navicular height and the arch height ratio significantly decreased from PRE to POST marathon (p < 0.001).
• The asymmetry of the arch height ratio was significantly greater POST than PRE marathon.
• Post-race navicular height asymmetry was predicted by pre-race asymmetry, while navicular height displacement was influenced by pre-race navicular height and marathon time.

Conclusions:

• Full marathon running leads to a significant lowering of the medial longitudinal arch.
• Marathon running induces and increases asymmetry in foot arch morphology.
• Pre-existing foot posture and running time are factors associated with post-marathon arch changes and asymmetry.