Differences in Foot Characteristics Between Bharatanatyam Dancers and Age-Matched Non-Dancers.

Abstract

The ankle-foot complex is the third most common site of pain in Indian dancers. In Bharatanatyam dance, rhythmic stamping performed barefoot at varying speeds may influence the height of the medial longitudinal arch, causing structural alteration of the ankle-foot complex. As little information is available on the ankle-foot complex of Bharatanatyam dancers, the present study was conducted to test the hypothesis that foot characteristics of Bharatanatyam dancers differ from those of non-dancers. Female professional Bharatanatyam dancers (n=21), aged 18-30 years, with a minimum of 8 years of performance experience after completing formal dance training, and 21 control non-dancers participated in this study. Physical foot examination included navicular drop test and Feiss line. Foot geometry and pedobarography were recorded as participants walked barefoot at self-selected walking pace over a pressure-platform. An average of five gait cycles was computed to analyse maximum peak pressure (MPP), pressure time integral, contact time, and foot geometry of the midfoot, forefoot, great toe, and second to fifth toes. Analysis of covariance was performed for intergroup comparison of all variables with gait speed as a covariate. During walking, dancers presented a higher medial-longitudinal-arch, wider midfoot, and wider forefoot (cm) (p<0.001), indicating an over-pronated foot due to lower medial longitudinal arch height. Total plantar peak pressure (kPa) was 37% higher among dancers, whereas MPP was 24% higher on midfoot and 13% higher on forefoot, indicating greater plantar loading during walking. Greater plantar loading and an over-pronated foot during the most commonly performed weight-bearing activity of daily living (e.g., walking) explain the common prevalence of ankle and foot pain among dancers. These findings will inform clinicians and Bharatanatyam dancers on dancer's foot function and guide strategies for prevention and management of foot pain.