Impact of Demographic and Impairment-related Variables on Disability Associated with Plantar Fasciitis

Background: Plantar fasciitis is a common foot disorder that impacts many functional activities. Research that quantifies the impact that plantar fasciitis has on function is lacking. In addition, little is known about which variables are associated with disability in patients with plantar fasciitis. The first purpose of this study was to determine if age, gender, body mass index, pain intensity, chronicity of symptoms, or ankle dorsiflexion range of motion was associated with disability in patients with plantar fasciitis. The second purpose was to describe the impact that plantar fasciitis has on functional status in the context of five functional domains: household activities of daily living, usual work and hobbies, nonweightbearing activities, walking-related activities, and running-related activities.

Methods: Fifty consecutive patients diagnosed with unilateral plantar fasciitis were recruited. Demographic and impairment data were collected and all patients completed the Lower Extremity Functional Scale (LEFS), a validated self-report measure of disability. Multiple regression analysis was used to describe the association between the variables and disability. Graphs depicting five domains of function derived from the LEFS were generated to describe the extent of disability.

Results: Body mass index (BMI) was the only variable that was significantly associated with disability (F = 9.87, p =.003). Measures of pain intensity, ankle dorsiflexion, age, gender, chronicity, and time spent weightbearing were not related to disability. Plantar fasciitis showed distinct patterns of disability depending on the functional domain that was assessed.

Conclusions: With the exception of BMI, impairment and demographic variables do not predict the extent of functional loss in patients with plantar fasciitis. The most likely domains of function to be at least moderately affected in patients with plantar fasciitis are running-related activities and usual work or hobbies.