  We calculate analytically the spin-orbital decomposition of the angular
momentum using completely non-paraxial fields that have certain degree of
linkage of electric and magnetic lines. The split of the angular momentum into
spin-orbital components is worked out for non-null knotted electromagnetic
fields. The relation between magnetic and electric helicities and spin-orbital
decomposition of the angular momentum is considered. We demonstrate that even
if the total angular momentum and the values of the spin and orbital momentum
are the same, the behaviour of the local angular momentum density is rather
different. By taking cases with constant and non-constant electric and magnetic
helicities, we show that the total angular momentum density present different
characteristics during time evolution.
