This work deals with the multi body dynamics modelling of the humanoid robots. An alternative geometric method will be presented based in the screw theory. The obtained torques are used for selecting the right motors. Otherwise, this computation allows to compute the joint torques at any humanoid robot motion, those are constrained for the physical robot limits. Furthermore, the joint torque references could be obtained for doing the torque control loop and develop any motion pattern. The simulation results in order to check the joint torques are shown and discussed. Copyright © 2008 by World Scientific Publishing Co. Pte. Ltd.