[Association of flatfoot with pain, fatigue and obesity in Japanese over sixties].

PURPOSE: There is still uncertainty whether flatfoot, characterized by lower height of the medial longitudinal arch of the foot, is associated with foot symptoms in adults. Furthermore, few studies have been conducted to examine any association with obesity in older people. In this study, we therefore assessed the prevalence of flatfoot among community-dwelling older men and women using a footprint method, and analyzed relationships with foot symptoms and obesity.

METHODS

The study sample consisted of 242 women and 98 men aged 60 years or older who were neither institutionalized nor disabled in activities of daily living. We collected footprints of both feet, data on weight and height, and information on foot symptoms and daily activity. From the footprints, we identified the H line by connecting the tip of the second toe and the intersection of the internal surface tangent of the foot and the external one. Then flatfoot was defined as concavity of the medial arch situated medial to the H line in either foot. Foot symptoms (pain and fatigue) were assessed using a 3-scale questionnaire: no pain (fatigue); present only when walking or standing; or present anytime. If present, the place of the pain or the fatigue was further identified. We analyzed associations with these symptoms and also with obesity assessed in terms of the body mass index (BMI).

RESULTS

We identified flatfoot in 26.5% (95% Confidence Interval: 22.0-31.0) of the men and 25.7% (95% Confidence Interval: 20.2-31.2) of the women. In both sexes, the affected individuals had a higher prevalence of foot pain and fatigue than those unaffected. The association with the latter in women was particularly significant. There was a linear association between prevalence of flatfoot with the BMI category in women. In addition, the prevalence was lowest in the least obese category in men although this did not reach statistical significance.

CONCLUSIONS

Flatfoot was significantly associated with the presence of pain and fatigue in women. Furthermore, a significant positive association with obesity was noted.