Biomechanical analysis of the effect of orthotic shoe inserts: a review of the literature.

Physical activity is increasingly recognised as an important component of primary disease prevention. Overuse injuries are common sequelae of exercise and sporting activities in general, and of running in particular, frequently resulting in cessation of activity. It has been proposed that there is a link between foot shape, foot function and the occurrence of injury. As a means of treatment and prevention of further injury, orthoses and shoe inserts are widely prescribed in the belief that they can alter the pattern of lower extremity joints' alignment and movement. Although this is an assumption widely made in the treatment of many joint conditions, the manner through which this treatment could be effective is not clear. This article aims to examine the literature to gain an improved understanding of the present state of knowledge regarding the effect of foot shape and orthotic use on foot kinematic and plantar pressure characteristics. The effects of foot type on the occurrence of lower limb injury during sporting activities and different aspects of biomechanics are reviewed, and the effects of applying orthoses on injury treatment and prevention and on various aspects of biomechanics of the lower limb joints are discussed. Further research is required, firstly to establish the casual effect of foot type and function on the risk of lower extremity overuse injury, and secondly to document the specific effect of orthotic therapy on injury treatment and prevention. Specifically, more prospective studies are necessary to investigate the long term effect of orthotic intervention.