Thickness of the Plantar Fascia in Asymptomatic Subjects

Ultrasound Strain Elastography Reliability in the Assessment of the Plantar Fascia and Its Relationship with the Plantar Thickness in Healthy Adults: An Intra and Interobserver Reliability Study in Novice Evaluators

PURPOSE

This study was aimed at verifying both the intraobserver and interobserver reliability of measuring plantar fascia stiffness for a given image in healthy active adults.

METHODOLOGY

This study is reported following the Guidelines of Reporting Reliability and Agreement Studies. A total of 20 plantar fascia from healthy volunteers were analyzed. The thickness of the plantar fascia was measured vertically from the anterior edge of the inferior calcaneal border to the inferior border of the plantar fascia and the ultrasound elastography measurement was taken at the calcaneal insertion of the plantar fascia with the region of interest one centimeter away from the insertion.

RESULTS

The ultrasound strain elastography measurements: the right intraobserver 1 showed an ICC value of 0.9 and the left intraobserver 1 showed an ICC value of 0.78, while the right intraobserver 2 showed an ICC value of 0.91 and the left intraobserver 2 showed an ICC value of 0.83. Interobserver measurements showed excellent reliability with a right ICC value of 0.8 and a left ICC value of 0.9 for the plantar fascia thickness measurements.

DISCUSSION

The results of this study showed a strong correlation between left and right plantar fascia thickness. The intraobserver reliability was excellent for both plantar fascia ultrasound strain elastography and thickness measurements, with interobserver measurements showing excellent reliability.

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.

Ultrasonic evaluation of plantar fascia in patients with osteoarthritis of the knee

To study the changes of plantar fascia in patients with knee osteoarthritis. Collect knee arthritis surgery patients and according to the length of the course is divided into long-course and short-course group, collection of healthy volunteers as control group at the same time, basic information such as age, height, weight, and body mass index (BMI) were recorded; the application of Philips and Siemens ultrasonic diagnostic instrument, a foot plantar fascia in patients with knee osteoarthritis in ultrasonic scanning, measuring the thickness of the heel of plantar fascia, observe its sonographic manifestation; age, BMI, and plantar fascia thickness were compared between groups. The plantar fascia thickness of the normal control group was 0.30 ± 0.06 cm on the left side and 0.30 ± 0.05 cm on the right side. The plantar fascia thickness of the long-course group was 0.44 ± 0.10 cm on the left side and 0.42 ± 0.10 cm on the right side. The plantar fascia thickness of the group with short course of disease was 0.37 ± 0.06 cm on the left side and 0.34 ± 0.7 cm on the right side. Multivariable analysis of variance was used to compare the thickness of plantar fascia in the long-course group, the short-course group, and the control group, P < .05; there were statistical differences among the 3 groups. Multivariate analysis of variance was used to compare the general data of the long-course group, the short-course group, and the control group. Age: the long-course group was compared with the short-course group and the control group, P < .05; short-course group compared with control group, P > .05. BMI: compared with long-course group and short-course group, P < .05; long course of disease group compared with short course of disease group, P > .05. BMI was statistically different between the case group and the control group. Plantar fascia was thickened in patients with knee osteoarthritis, and the thickening of plantar fascia was related to BMI. The thickening of plantar fascia was uneven, and the degree of thickening was related to the course of disease. At the same time, the sonogram of plantar fascia was less echogenic than that of normal controls.