Basic difficulties of the adequate and precise electrophysiological examination of radial nerve injuries are traditionally conditioned by the impossibility to separate the muscle, isolated from the muscles, innervated by the ulnar or medial nerves. The phenomenon of flexor motor units potentials propagation by the stimulating electroneuromyography and M-flow registration from extensor muscles has been described in literature. To prevent the false interpretation of the examination results, 98 patients with radial nerve injuries were examined using the original program of separate assessment of motor and sensor fibers.