Secondary evoked muscle potential mapping according to the F, H, HF, FH features of nonexistence in proximal and distal limb muscles. A preliminary communication.

In 62 healthy volunteers, a late response analysis was done in 23 leg and arm muscles. The potentials were differentiated according to their H-potential or F-potential features. The total disappearance of secondary potential was estimated also. The H-potential appeared most frequently in the thigh muscles (100%), frequently in the calf and peroneus longus muscles (77%-23%), rarely in the intrinsic foot muscles (20%), and never in the short or long foot and toe extensors. In the arms the H potential was most frequently found in flexor digitorum sublimis (67%). Its appearance in pronator quadratus was 22%. H-potential appeared rarely in the intrinsic hand muscles and never in the extensor digitorum communis. The similarity of H-wave distribution in the lower leg and feet muscles, and the lower arm and hand muscles is pointed out. The question of its phylogenetic determination is raised.