  Shell model calculations reveal that the ground and low-lying yrast states of
the $N=Z$ nuclei $^{92}_{46}$Pd and $^{96}$Cd are mainly built upon isoscalar
spin-aligned neutron-proton pairs each carrying the maximum angular momentum
J=9 allowed by the shell $0g_{9/2}$ which is dominant in this nuclear region.
This mode of excitation is unique in nuclei and indicates that the spin-aligned
pair has to be considered as an essential building block in nuclear structure
calculations. In this contribution we will discuss this neutron-proton pair
coupling scheme in detail. In particular, we will explore the competition
between the normal monopole pair coupling and the spin-aligned coupling
schemes. Such a coupling may be useful in elucidating the structure properties
of $N=Z$ and neighboring nuclei.
