The forward matrix elements of energy momentum-tensor proportional to tensor polarization are related to average shear force in hadron. It is zero when summed over quarks and gluons
due to equivalence principle. There is an evidence for its validity separately for quarks and gluons in deuteron, manifesting the extension of the equivalence principle. The experimental tests may be performed in DIS and other hard processes, like high $p_T$ hadrons production. The shear viscosity for hadrons and its relation with exotic hybrid mesons production is discussed