Epidemiology of Shoe Wearing Patterns Over Time in Older Women: Associations With Foot Pain and Hallux Valgus

Footwear plays an important role in protecting the foot. The earliest known footwear, dating from approximately 7,500 BCE, were simple sandals secured around the ankle with rope (1), whereas the first direct evidence of footwear covering the foot dates back to 3,500 BCE (2). The functional role of footwear was diminished by fashion influences from the 15th century, as features such as high heels and extended toe boxes became popular (3). Modern footwear has retained vestiges of these early fashion influences, many of which are thought to be associated with foot pain and deformity (4). Consequently, shoe-related foot disorders represent an important public health problem (5). Indeed, the annual economic impact of foot problems caused by footwear has been estimated as $3 billion in the United States alone (6). Some styles of women’s footwear encompass two key design features, an elevated heel and a constrictive toe box, that are considered to be particularly detrimental to the foot (7). Biomechanical studies have revealed that heel elevation increases the pressures under the metatarsal heads (8), limits motion of the first metatarsophalangeal joint (9), and increases the stiffness of the Achilles tendon (10), whereas shoes with a narrow toe box increase pressures on the medial side of the foot and between the toes (11). Over time, these changes may contribute to the development of foot pain and deformity. Cross-sectional studies have shown that wearing shoes with an elevated heel is associated with hallux valgus and plantar calluses (12), and wearing shoes with a constrictive toe box is associated with hallux valgus (12,13) and foot pain (12,14). Furthermore, studies involving recall of previous footwear use have reported a protective effect of ‘good’ shoes in relation to foot pain (15) and an association between high heel use and hallux valgus (5,16). Establishing an association between footwear characteristics and foot problems, however, is inherently difficult, as shoe wearing behaviors are likely to vary as a function of both age and period—the interaction of these producing cohort effects (17). Footwear selection in women reflects changes across the life course in fashion consciousness, identity and health status (18). Furthermore, these age- and life-stage changes in footwear selection are expressed in the context of changing footwear fashions, and their availability and affordability. Therefore, in order to better understand the relationship between footwear and foot problems, it is necessary to adopt a life-course approach to estimate past exposure to potentially detrimental footwear behaviors. Accordingly, the aims of this study were to (i) examine shoe wearing patterns over time in older women in relation to the height of the heel and the shape of the toe box and (ii) evaluate associations between these footwear characteristics and current foot pain and hallux valgus.