Effect of Age and BMI on Sonographic Findings of Plantar Fascia

Biomechanical dysfunction of the foot is most common cause of plantar fascia disorder and obesity and increasing age are well-known risk factors. Due to being inexpensive and quick, ultrasound imaging techniques are considered the modality of choice to assess plantar fascia. The aim of this study was to investigate the effect of age and body mass index (BMI) on sonographic findings of plantar fascia in normal population. Ultrasonography was used to measure the plantar fascia thickness of 148 healthy adults (54 males, 36.5% and 94 females, 63.5%) during a period of one year. The age, BMI, and walking distance of each participant were recorded and statistically analyzed. The mean plantar fascia thicknesses at 0.5, 1.0, and 2.0 cm distal to the insertion of the plantar fascia were 1.76 ± 0.32 mm, 2.50 ± 0.50 mm and 2.11 ± 0.41 mm respectively. The mean plantar fascia thickness for individuals ≥45 years and BMI ≥25 were significantly higher (p < .001) compared to individuals <45 years and BMI <25. In a normal population, the thickness of the plantar fascia determined by ultrasound measurement was less than 3 mm. We recommend using the position 1.0 cm distal to the calcaneal insertion of the plantar fascia as the reference point for diagnosing plantar fasciitis. The thickness of plantar fascia was significantly increased with age and BMI whereas gender, walking activity, exercise and running did not seem to affect the plantar fascia thickness.