Contusion may effect a sort of STUPEFACTION OF MUSCLE and paralyze it by a non-psychic process: The SYNERGY in contraction of biceps and supinator longus is thus SPLIT. Biceps restored to synergy with the supinator by massage and faradism.
A man was wounded at about the middle of his biceps and three weeks later was found to be able to flex the forearm only by means of the supinator longus. The biceps remained absolutely flaccid and soft, so that the diagnosis of a lesion of the musculocutaneous nerve (unlikely as this seemed on account of the low site of the wound) was entertained.
However, the biceps and the musculocutaneous nerve proved electrically normal. In short, this paralysis of biceps was functional in nature. But, according to Tinel, there could be no voluntary suggestive or hysterical element in such a paralysis, since flexion of the forearm is normally produced by a synergic contraction of biceps and supinator longus that cannot be separated voluntarily.
Treatment by massage and rhythmic faradization caused the biceps function to return to normal, so that voluntary synergic contractions of the biceps took place along with those of the supinator longus.
We here deal, according to Tinel, with a genuine functional paralysis, nonhysterical—a paralysis due to a kind of stupor of the muscle. Such paralyses due to muscular stupor ought to get well in a few days or weeks. Should they persist, it is clear that a stuporous paralysis might be transformed into a hysterical paralysis. In short, the direct contusion of a muscle or group of muscles may be the point of departure for various persistent paralyses.