Improving the design of the curved rocker shoe for people with diabetes

......................................................................................................1 0 Chapter 1: Introduction ................................................................................................................. 12 1.1 Diabetes and the impact of plantar foot ulcers ................................................................. 12 1.2 Aetiology of ulceration in diabetes .................................................................................... 14 1.3 The epidemiology of foot ulceration in people with diabetes .......................................... 16 1.3.1 Overview of the different risk factors ........................................................................... 16 1.3.2 Neuropathy as a risk factor for ulceration ..................................................................... 18 1.3.3 Elevated plantar pressure and other risk factors for ulceration ..................................... 20 1.4 Interventions designed to reduce the risk of ulceration diabetes.................................... 22 1.5 Structure of the literature review ...................................................................................... 24 1.6 Structure of the thesis ......................................................................................................... 25 1.7 Statement of ownership ...................................................................................................... 27 Chapter 2: Literature review......................................................................................................... 29 2.1 Pressure and the relationship with ulceration .................................................................. 32 2.1.1 Epidemiological studies investigating the link between plantar pressure and ulceration ...................................................................................................................................................32 2.1.2 Plantar pressure versus shear ........................................................................................ 33 2.1.3 Tissues mechanics associated with elevated plantar pressure ....................................... 34 2.1.4 Biomechanical factors associated with elevated plantar pressure ................................. 35 2.1.5 Plantar pressure and the site of ulcers ........................................................................... 37 2.2 Plantar pressure measurement methods ........................................................................... 39 2.2.1 Instrumentation ............................................................................................................. 39 2.2.2 Plantar pressure analysis ............................................................................................... 40 2.3 Types of Footwear used to reduce ulceration and pressure ............................................ 42 2.3.1 The evidence for the prevention/recurrence of ulceration and pressure with therapeutic footwear 42 2.3.2 Evidence for reduction in pressure with therapeutic footwear ...................................... 43 2.3.3 Features of footwear that affect plantar pressure .......................................................... 46 2.3.4 Different approaches to designing a rocker outsole ...................................................... 48 2.3.5 Evidence for the effectiveness of rocker shoes ............................................................. 51 2.3.6 Studies which have systematically varied the individual design features of rocker shoes ..................................................................................................................................................53 2.4 Factors which may influence in-shoe plantar pressure and therefore influence how an individual responds to a specific rocker shoe design ................................................................... 56 2.4.1 The possibility of predicting shoe design using gait inputs .......................................... 56 2.4.2 Hypothesis of how the different design features might affect pressure in different individuals ..................................................................................................................................... 58 2.5 Summary of literature review ............................................................................................ 62 2.6 Scope and boundaries of the project ................................................................................. 63 Chapter 3: (Study 1) Understanding the effect of systematically varying the three principle design features of a rocker shoe in people with and without diabetes ........................................... 67 3.