  The definition of the physical properties of particles in perturbative gauge
theories must satisfy gauge invariance as a requisite. The Pinch Technique
provides a framework to define the electromagnetic form factors and the
electromagnetic static properties of fundamental particles in a consistent and
gauge-invariant form. We apply a simple prescription derived in this formalism
to check the calculation of the gauge-invariant one-loop bosonic electroweak
corrections to the muon anomalous magnetic moment.
