Muscle Activation of the Lower Limb in Response to a Medio-lateral Imbalance in Monopodal Stance

The "static" single-leg stance has been extensively studied in the literature for its relevance in functional evaluation, therapeutic exercise, sports training and research for fall prevention (particularly for the elderly and patients with neurological diseases). However, the motor strategies of the supporting limb have been investigated only at the ankle level. In particular it is not known, at the hip, how the muscular system reacts to medial and lateral imbalances. Colonna has hypothesized, basing on a myofascial chains approach, that the balance is managed by the front and back spiral chains. The aim of the present study is to perform a preliminary experimental analysis to verify Colonna's hypothesis, testing a method for the investigation of motor strategies underlying equilibrium. Five healthy subjects will be examined by means of electromyographic analysis of the gluteus maximus, gluteus medius, adductor longus, tibialis anterior and peroneus longus. Subjects will undergo perturbations of their monopodal balance.