  Constrained mechanical multibody systems arise in many important applications
like robotics, vehicle and machinery dynamics and biomechanics of locomotion of
humans. These systems are described by the Euler-Lagrange equations which are
index-three differential-algebraic equations(DAEs) and hence difficult to treat
numerically. The purpose of this paper is to propose a novel technique to solve
the Euler-Lagrange equations efficiently. This technique applies the Adomian
decomposition method (ADM) directly to these equations. The great advantage of
our technique is that it neither applies complex transformations to the
equations nor uses index-reductions to obtain the solution. Furthermore, it
requires solving only linear algebraic systems with a constant nonsingular
coefficient matrix at each iteration. The technique developed leads to a simple
general algorithm that can be programmed in Maple or Mathematica to simulate
real application problems. To illustrate the effectiveness of the proposed
technique and its advantages, we apply it to solve an example of the Euler-
Lagrange equations that describes a two-link planar robotic system.
