Identification of muscle determinant for different gait speeds by proper orthogonal decomposition

In this investigation, we explore the use of the proper orthogonal decomposition (POD) on electromyography (EMG) of the leg muscles, with the objective of elucidating the muscles behavior for each gait speeds. Four different gait speeds were used in the study: slow, comfortable, fast and fastest walking. The electromyographic data used in this study were recorded from 12 bilateral lower limb muscles: tensor fascia latae (TFL), semitendinosus (ST), vastus medialis (VM), rectus femoris (RF), tibialis anterior (TA) and medial gastrocnemius (MG). Results indicate that the primary muscles for these gait speeds were bilateral TFL which act alternately to accept weight bearing on each leg. The same muscles also show another dominant function when working simultaneously in pelvic stabilization. In addition, we found that when the speed of walking increases, the number of muscle determinants for gait has been added. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)