Effects of obesity on foot outcomes and quality of life in women with plantar fasciitis

Background & Aim: Plantar fasciitis (PF) is the most common foot dysfunction, which accounts for about 40% of all foot conditions. It limits activities of daily living (ADL) and quality of life (QoL). Obesity reduces the prognosis of many conditions. However, evidence is unclear on how it affects women with PF. This study aimed to identify the effects of obesity on foot outcomes in women with PF.

Methods: A cross-sectional study was conducted at the Departments of Rheumatology and Rehabilitation (General and Special) of the National Hospital of Sri Lanka. Fifty-four women with PF were recruited under three categories: obese (BMI>30), overweight (25<BMI<30), or not overweight (BMI<25), using simple random sampling. QoL and disability associated with PF were assessed using SF-36 and Foot Function Index (FFI). Ankle dorsiflexion range of motion, foot arch height, calf endurance, and ankle muscle strengths were measured using the Weight-bearing Lunge Test (WBLT), Static Arch Index, Calf Heel Raises, and Hand-held Dynamometer, respectively. Data were analyzed using one-way ANOVA and Tukey post hoc tests in SPSS v21

Results: Fifty-four women with unilateral plantar fasciitis with a mean age of 46.17 years (SD ± 5.08) and BMI of 27.19kgm-2 (SD ± 3.75) participated in the study. The higher BMI group had a significantly low SF-36 score (p=0.002) and higher FFI score (p=0.002), indicating poor QoL and higher suffering from plantar fasciitis despite the similar treatment they underwent. Furthermore, WBLT score (p<0.001) and dorsiflexor strength (p=0.033) were significantly lower in higher BMI categories, meaning less dorsiflexor range and strength in obese women. However, plantar flexor strength (p=0.827), calf endurance (p=0.887), and arch height (p=0.466) did not differ significantly across BMI categories.

Conclusions & Recommendations: Obese women with PF presented with lower QoL, poor foot functioning, and reduced dorsiflexor muscle strength and range of motion.