Footprint‐based estimates of arch structure are confounded by body composition in adults

Abstract

Previous research employing indirect measures of arch structure, such as those derived from footprints, have indicated that obesity results in a ''flatter'' foot type. In the absence of radiographic measures, however, definitive conclusions regarding the osseous alignment of the foot cannot be made. We determined the effect of body mass index (BMI) on radiographic and footprint-based measures of arch structure. The research was a cross-sectional study in which radiographic and footprint-based measures of foot structure were made in 30 subjects (10 males, 20 female) in addition to standard anthropometric measures of height, weight, and BMI. Multiple (univariate) Previous research employing footprint-based measures of arch structure, such as the Arch Index (AI), have typically reported a ''flatter'' foot in obese adults and children. 1-6 ''Flat feet'' have been suggested to increase stress within soft tissue structures of the lower limb and thereby increase the propensity for injury. 7 While clinical data have confirmed a greater prevalence of musculoskeletal pain in obese individuals, primarily involving the lower limb, 8,9 body adiposity has also been shown to influence the amount of soft tissue beneath the foot. 10-12 Moreover, positive linear associations have been found between estimates of total body fat, derived from bioelectrical impedance, and the midfoot contact area of footprints. 13 As such, obesity has been hypothesized to act as a potentially confounding factor in footprint-based estimates of arch structure.In support of this concept, Gilmour and Burns 14 found that while footprint-based estimates of arch height differed between obese and normal weight children, caliper measures of navicular height did not. Thus, it would appear that obesity may selectively distort the contact area of the foot, without affecting the osseous structure of the medial longitudinal arch. However, the validity of skin-based caliper measures of arch structure, particularly in obese populations, is questionable, 15 and in the absence of radiographic measures, definitive conclusions regarding the effect of obesity on the osseous alignment of the foot cannot be made.The aim of the current investigation, therefore, was to evaluate the effect of body mass index (BMI) on both radiographic and footprint-based measures of adult arch structure. We hypothesized that footprintbased measures of arch height would be linearly associated with adiposity, as defined by the BMI, while radiographic measures of foot structure would not. MATERIALS AND METHODS ParticipantsA convenience sample of 30 healthy volunteers (10 male and 20 female) were recruited from the greater Brisbane metropolitan area. Participants possessed a mean (SD) age of 47.9 (11.6) years, height of 1.68 (0.10) m and body weight of 80.8 (10.2) kg. The average BMI for the group was 28.8 (2.9) kg m À2 with values ranging from 23.9 kg m À2 (normal weight) to 35.2 kg m À2 (obese class II). 16 Study participants with a history of lower limb pain within 3 months of the ...

The relationship between flat feet and cavus foot with body mass index in girl students

“…They said that the likelihood of a flat foot in obese and overweight children was three times more likely than normal-weight children [22]. On the other hand, an increase in the AR index value with the increase in BMI, as indicated in the present study, is consistent with studies that have examined the effect of BMI on the basis of radiography and arc structure in adults [23]. Most of our samples are in the body composition in the second group, the natural combination.…”

The relationship between body mass index and footprint parameters in older people

“…Their studies claimed that AI measurements are dependent on body structure in obese cases and do not demonstrate the exact height of the medial longitudinal arch [25,26]. Although the criticism has to be considered while interpreting the results of the current study, this does not alter the clinical importance of flatfoot in obese older adults.…”

Excessive Weight Bearing Compromises Foot Structure and Function Across the Lifespan

“…Whereas BMI was a significant (p = 0.04) predictor of footprint-based measures of arch height, arch structure quantified by a radiographic measure of the medial longitudinal arch was not significantly associated with BMI (p = 0.89). The authors concluded that although adult obesity selectively distorts footprint-based measures of arch structure by increasing the midfoot contact area, it does not influence osseous alignment of the medial longitudinal arch in adults [94].…”

“…Of the few studies that have examined the feet of adults, most have confirmed that obese adults typically display the broader, wider and flatter foot structure typical of obese children [85,93,94]. For example, Gravante et al [93] compared the contact area of the feet of 38 obese young adults (23 women: age = 23.4 ± 3.6 years, BMI 38.0 ± 6.8 kg/m 2 ; 15 men: age = 23.9 ± 4.6 years, BMI 36.0 ± 7.4 kg/m 2 ) and 34 healthy controls (18 women: age = 23.3 ± 2.3 years, BMI 21.9 ± 1.4 kg/m 2 ; 16 men: age = 22.4 ± 1.9 years, BMI 22.6 ± 1.6 kg/m 2 ).…”

“…Sonographic examinations have revealed that increases in body adiposity can influence the amount of soft tissue beneath the feet in both children [52,68] and adults [103]. However, Wearing et al [94] determined the effect of variations in BMI on the structure of the arch of the foot in a convenience sample of 10 male and 20 female healthy volunteers (age = 47.9 ± 11.6 years; BMI = 28.8 ± 2.9 kg/m 2 ). The arch of the foot was characterised by both radiographic and footprint-based measures using a pressure platform.…”