title: Factors Associated With Callus in Patients with Diabetes, Focused on Plantar Shear Stress During Gait.
abstract: The aim of this study is to identify whether plantar shear stress in neuropathic patients with diabetes with callus is increased compared with those without callus.
  
  
  
  The differences in foot deformity, limited joint mobility, repetitive stress of walking, and ill-fitting shoes between patients with callus and those without callus were also determined. Subjects were recruited from the Diabetic Foot Outpatient Clinic. A newly developed in-shoe measurement system, which has flexible and thin insoles, enabled measurement of both plantar pressure and shear stress simultaneously when subjects walked as usual on a 10 m walkway.
  
  
  
  It was found that plantar shear stress adjusted for weight during the push-off phase was increased by 1.32 times in patients with callus compared with those without callus (mean ± SD: 0.0500 ± 0.0160 vs 0.0380 ± 0.0144, P = .031). Moreover, hallux valgus deformity, reduction in dorsiflexion of the ankle joint and increase in plantar flexion were showed in feet with callus. Increased plantar shear stress may be caused by gait change that patients having callus push off with the metatarsal head instead of the toe as a result of foot deformity and limited joint mobility.
  
  
  
  It was found that plantar shear stress adjusted for weight during the push-off phase was increased in patients with callus compared with those without callus by using the newly developed measurement system. These results suggest that reduction of plantar shear stress during the push-off phase can prevent callus formation in neuropathic patients with diabetes.
authors.affiliation: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Hamatani
authors.affiliation: Life Support Technology (Molten), Graduate School of Medicine, University of Tokyo, Tokyo, Japan tmoriics-tky@umin.ac.jp.
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Mori
authors.affiliation: Department of Advanced Nursing Technology, Graduate School of Medicine, the University of Tokyo, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Oe
authors.affiliation: Life Support Technology (Molten), Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Department of Nursing Administration/ Advanced Clinical Nursing, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kimie
authors.initials: K
authors.lastname: Takehara
authors.affiliation: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Amemiya
authors.affiliation: The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Ohashi
authors.affiliation: Department of Molecular Sciences on Diabetes, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kohjiro
authors.initials: K
authors.lastname: Ueki
authors.affiliation: Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kadowaki
authors.affiliation: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sanada
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D002145:Callosities / Q000209:etiology*; D003430:Cross-Sectional Studies; D017719:Diabetic Foot / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D005528:Foot / Q000473:pathology* / Q000503:physiopathology*; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D013314:Stress, Mechanical
keywords: diabetes mellitus; diabetic foot; foot ulcer; gait; shear strength; shoes