In this work, movement of the exoskeleton wearer and the metabolic energy changes with the assisted devices using OpenSim platform has been attempted. Two musculoskeletal models, one with torsional ankle spring and the other with bi-articular path spring are subjected to forward dynamic simulation.The changes in the metabolic rate of the lower extremity muscles before and after the addition of the assistive devices were tested. The results about the effect of these external devices on individual muscles of the lower muscle group were analysed which provided effective results.