A Prospective Study of Risk Factors

Background: Sever’s disease, also known as calcaneal apophysitis, is thought to be an inflammation of the apophysis of the heel, which is open in childhood. This condition has been commented on and looked at in a retrospective manner but has not been examined systematically. We assembled the most commonly cited theoretical causative models identified from the literature and tested them to determine whether any were risk factors. Methods: Children with Sever’s disease were compared with a similarly aged nonsymptomatic population to determine whether identifiable risk factors exist for the onset of Sever’s disease. Areas raised in the literature and, hence, compared were biomechanical foot malalignment, as measured by Root et al–type foot measurements and the Foot Posture Index; ankle joint dorsiflexion, measured with a modified apparatus; body mass index; and total activity and types of sport played. Results: Statistically significant but small odds ratios were found in forefoot to rearfoot determination and left ankle joint dorsiflexion. Conclusions: This study suggests that there is no evidence to support that weight and activity levels are risk factors for Sever’s disease. The statistically significant but clinically negligible odds ratio (0.93) on the left side for decreased ankle joint dorsiflexion and statistically significant and clinically stronger odds ratio bilaterally for forefoot to rearfoot malalignment suggest that biomechanical malalignment is an area for further investigation. (J Am Podiatr Med Assoc 101(2): 133-145, 2011)