Manufacturing methodology for personalised symptom-specific sports insoles

Orthotic insoles are used for numerous applications; they can be prescribed to treat medical conditions such as rheumatoid arthritis and to maintain the health of the feet of diabetic patients. Orthotic devices are also extensively used in sporting activities and can be used for improving skeletal function, thus enhancing the biomechanical performance of the user and subsequently providing a more economical gait. This paper focuses on the manufacture of sports insoles and provides a methodology for the design and manufacture of a personalised symptom-specific sports (3S) insole. The framework includes the biomechanical assessment methods required for the effective prescription of a personalised insole. The requirements of a functional insole should relate not only to the geometry and condition of the foot but also the application in which it will be used. Different sports are played using specialised footwear, on varying surfaces and using diverse movements and so require an alternative design regarding the geometry and materials used. Thus novel manufacturing methods are required and two examples are described, namely the cryogenic machining of soft foamed polymers to achieve suitable impact attenuation and the autoclaving of a carbon-fibre composite material to produce a slim, rigid design. (C) 2009 Elsevier Ltd. All rights reserved.