title: Plantar pressures, plantar forces, and their influence on the pathogenesis of diabetic foot ulcers: a review.
abstract: BACKGROUND
  Clinical recommendations for the prevention and healing of diabetic foot ulcers (DFUs) are somewhat clear. However, assessment and quantification of the mechanical stress responsible for DFU remain complex. Different pressure variables have been described in the literature to better understand plantar tissue stress exposure. This article reviews the role of pressure and shear forces in the pathogenesis of plantar DFU.
  
  
  METHODS
  We performed systematic searches of the PubMed and Embase databases, completed by a manual search of the selected studies. From 535 potentially relevant references, 70 studies were included in the full-text review.
  
  
  RESULTS
  Variables of plantar mechanical stress relate to vertical pressure, shear stress, and temporality of loading. At this time, in-shoe peak plantar pressure (PPP) is the only reliable variable that can be used to prevent DFU. Although it is a poor predictor of in-shoe PPP, barefoot PPP seems complementary and may be more suitable when evaluating patients with diabetes mellitus and peripheral neuropathy who seem noncompliant with footwear. An in-shoe PPP threshold value of 200 kPa has been suggested to prevent DFU. Other variables, such as peak pressure gradient and peak maximal subsurface shear stress and its depth, seem to be of additional utility.
  
  
  CONCLUSIONS
  To better assess the at-risk foot and to prevent ulceration, the practitioner should integrate quantitative models of dynamic foot plantar pressures, such as in-shoe and barefoot PPPs, with the regular clinical screening examination. Prospective studies are needed to evaluate causality between other variables of mechanical stress and DFUs.
authors.affiliation: Hyperbaric Unit and Complex Wound Unit, CSSS Alphonse Desjardins/Centre Hospitalier Affilié Universitaire de Lévis, Lévis, Québec, Canada.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Patry
authors.forename: Richard
authors.initials: R
authors.lastname: Belley
authors.forename: Mario
authors.initials: M
authors.lastname: Côté
authors.forename: Marie-Ludivine
authors.initials: ML
authors.lastname: Chateau-Degat
mesh_terms: D003920:Diabetes Mellitus / Q000503:physiopathology; D017719:Diabetic Foot / Q000209:etiology* / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000503:physiopathology; D005528:Foot / Q000503:physiopathology*; D006801:Humans; D011312:Pressure; D018570:Risk Assessment; D012775:Shoes; D013314:Stress, Mechanical