  In the framework of the product ansatz as an approximation for the two-baryon
system we review in details the derivation of the isoscalar nucleon-nucleon
spin orbit potential coming from the sixth order term of the extended Skyrme
model. We show that the sixth order term contributes with a positive sign, as
is the case for the Skyrme term, contrary to the claims of Riska and
Schwesinger. Those authors considered only one part of the force due to the
sixth order term and omitted the second part which turns out to be the dominant
one. Our result is independent of the parameters of the model.
