[en] The effects of the propagation of isobaric nucleon states in the intermediate steps of the multiple scattering have been studied with application on the proton-⁴He elastic scattering at 1 GeV. The calculations are performed in the Glauber model and results are given for the differential cross section, the polarization and the spin rotation parameter. In our conclusions we stress the large cancellations observed between terms of various orders and the great sensitivity of the effects to the nucleon-nucleon amplitudes