Body Mass Index Predicts Function in Individuals With Plantar Fasciopathy: A Longitudinal Observational Study.

Context: Plantar fasciopathy (PF) is a common, self-limiting condition with notable economic impact and multifactorial origins. Clinical tests help clinicians to identify specific dysfunction and limitations influencing PF's clinical course. This study aims to investigate whether body mass index (BMI) influences the performance of clinical tests and clinical presentation of individuals with PF and to determine whether BMI and clinical tests predict the clinical course of PF over a 3-month follow-up period.

Design: This study is a longitudinal observational study. Participants were grouped, according to the median BMI, into low and high BMI.

Setting: Healthcare centers and physiotherapy clinics.

Participants: Fifty-two individuals with PF participated in this study.

Main outcome measures: Baseline: Ankle dorsiflexion range of motion and navicular drop, heel-rise, and step-down tests were administered. Pain intensity and function were measured at baseline and at 3-month follow-up.

Results: Low BMI group showed better function (mean difference = 11.8; 95% CI, 1.9 to 21.6) and lower pain intensity (mean difference = -1.5; 95% CI, -2.6 to -0.3) than the high BMI group. In the multivariable regression model, higher BMI predicted lower function (beta coefficient = -1.20; 95% CI, -2.3 to -0.3).

Conclusions: In individuals with PF, BMI levels influenced PF clinical presentation. The high BMI group showed more severe pain and lower function. Higher BMI was found to be a poor prognostic factor for function in individuals with PF.