The biomechanics of heel ulcers

Heel ulcers are common, dangerous and costly, but their etiology is poorly understood and no biomechanical studies were conducted to explore it. This paper describes a biomechanical investigation of heel ulcers using a theoretical model that characterizes the internal mechanical loading at the soft tissues of a supported heel. The study is aimed first at identifying some heel-ulcer-specific risk factors pointed out by the biomechanical theory, and second, at demonstrating the kind of support that biomechanical theory and computer modeling can offer in the conduct of clinical studies in the pressure ulcer field. The modeling demonstrated that atypical foot anatomies characterized by heavy-weight foot, sharp posterior calcaneus and thin soft tissue padding are theoretically more prone to heel ulcers. Diabetes and edema at the feet were also predicted to impose risks for heel ulcers, which agrees very well with clinical observations. This paper therefore demonstrated that a biomechanical theory can be used to explain and interpret clinical and epidemiological findings related to heel ulcers.