Biomechanical Function of the Plantar Intrinsic Foot Muscles

1,2 Luke Kelly, 2 Glen Lichtwark, 1 Rodney Whiteley, 1 Sebastien Racinais and Andrew Cresswell ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Centre for Sensorimotor Neuroscience, School of Human Movement Studies, The University of Queensland, Australia INTRODUCTION The human foot is a flexible multi-segment structure, capable of conforming to variations in load and surface to maintain effective force transmission between the lower limb and the ground. This functionality is achieved via an intricate interaction of movements occurring in a series of small joints (Leardini et al., 2007) which allows the longitudinal arch (LA) to deform during early stance, attenuating impact forces. Later in stance the LA stiffens via the windlass mechanism (Hicks, 1954). Regulation of foot stiffness has traditionally been considered to be due to passive mechanisms of the plantar aponeurosis (Ker et. al., 1987), however recent studies have suggested that active muscular control may also contribute (Caravaggi et al., 2010).