Abdominal muscles. Lordosis, without projection backward of shoulders.
50 See Duchenne, loc. cit., and also Roth, On Paralysis in Infancy, London, 1869.
After the paralysis the most remarkable symptom of anterior poliomyelitis is the rapid wasting of the paralyzed muscles. The atrophy begins within a week after the paralysis, and its progress is even more rapid than that following the section of a nerve. Sometimes all the flesh on a limb is shrivelled down to the bone; at other times the muscular atrophy is concealed by an abnormal development of fat, constituting a pseudo-hypertrophy. When all the muscles surrounding a joint are equally paralyzed and atrophied, no deformity develops,51 unless, indeed, the segment of a limb is used by means of the non-paralyzed proximate segment. In this case deformities may be produced by the effect of weight quite irrespective of muscular action, or in directions opposed to what we should expect from that.
51 Except talipes equinus.
The weight of the limb or a portion of it, by stretching paralyzed muscles, often aggravates their atrophy. This is most likely to occur with the paralyzed deltoid when the arm is unsupported, and with the anterior tibial muscles when the foot is allowed to drop.
Muscular atrophy occurs in the spinal paralysis of adults as well as in children; but in the latter alone does the atrophy extend to the bones and cartilages, tendons, fascia, ligaments, and blood-vessels. The osseous projections to which the muscles are attached waste; so do the epiphyses.52 The long bones are thinner and shorter, the foot is shorter, and the hand is shortened in paralysis of the upper extremity, even where this is limited to the upper arm, and the forearm is scarcely affected (Seeligmüller).
52 Seeligmüller, Centralbl. f. Chirug., No. 29, 1879.
In exceptional cases the limb may become even elongated from passive extension of the ligaments of the articulation. The bones may become soft and flexible, and break if pressure be applied.53
53 Ch. Salomon, “Des Lesions osseuses et articulaires lieés aux Maladies du Système nerveux,” Revue mensuelle, No. 8, 1878.
Atrophy of the bones stands in no fixed relation to that of the muscles, now exceeding, now falling short of that in intensity. This naturally progresses more slowly; still, within seven or eight months there may be a centimeter of difference between two limbs.