Intrinsic hand muscles: how to stimulate them (as simple as it is)

It is possible to stimulate selectively intrinsic hand muscles. In my experience, small electrodes applied dorsally in the intermetacarpal space works just fine, provoking metacarpophalangeal flexion and interphalangeal extension on the corresponding finger. Also, intrinsic thumb muscles can be stimulated selectively with the same approach (small electrodes, identification of optimal site, and please be careful with stimulation intensity!).