Background and aim: Flatfoot is characterized based on the height of the medial longitudinal arch of the foot relative to ground. The most common methods used to evaluate the severity of flatfoot and influences of the foot insole on the alignment of the foot structure in static situation are footprints and the use of X-ray. However, both of them have some limitations and cannot be used during walking while the subject uses the insole. Therefore, the aim of this research was to find a parameter which represents the alignment of the foot structure while walking.
Methods: Two groups of normal and flat-arched subjects were recruited into this study. The location of center of ankle joint (COJ) and center of pressure (COP) while walking was obtained using Qualysis motion analysis system and a force plate. The area between COP and COJ in the medial side to the total area was the new parameter used in this study.
Conclusion: The mean value of the new parameter was 74.65 ± 7.15 and 91.86 ± 12.4 for normal and flatfooted subjects, respectively. It appears that the new parameter can be used to check the alignment of the foot structure during walking.
Clinical statement: The results of this research study can be used by clinicians to determine the alignment of the foot structure and the influence of the foot insole.
