Most children whose bad carriage elicits steady complaints from the parents exhibit this postural anomaly. The causes of the deformity may be traced back in the main to the fact that children try to hold and fix their trunks with as little muscular action as possible.
To hold the spine in such a position as to conform with the physio logical curvature, a continuous action of the erectores spina; as well as the flexor and extensor muscles of the hip is essential. However, the constant muscular activity becoming tiresome in a short time, the children seek to fix the spine by positive contraction of muscles and checking of ligaments. This is done by the dorsal and lumbar portions of the spine assuming a totally kyphotic curvature. The ligaments inserted along the posterior aspect of the spine, the ribs and spinal pro cesses, act in opposition while the vertebral bodies are pressed together at the front of the spine, thus producing a rigidity of the otherwise flexible structure.
Aside from these vertebral changes, other variations of normal posture are often found in these cases and may be briefly mentioned.
In nearly all dorsolumbar kyphoses a markedly decreased inclina tion of the pe vis is noticeable.
This attitude, as in the kyphotie fixation of the spine, is likewise by passive contraction of ligaments, which acts as a substitute for the tiring muscles.
Children with weak or inactive muscles and "round backs" avoid all straining motions of the flexor and extensor muscles of the hip, which are needed in maintaining the normal posture of the pelvis. Instead they keep lowering the posterior part of the pelvis until the muscles of the hip which are inserted along the anterior border of the pelvis (tensor fasciae, sartorius, iliopsoas) become quite tense as well as the anterior ligaments of the capsule of the hip-joint.
Filially, these children with round backs let their shoulders drop for ward and downward in order to eliminate as much as possible the irksome activity of the shoulder muscles (elevation and backward traction).
The pathological changes in round backs of school children consist principally in an over-extension of the ligaments and muscles situated on the posterior aspect. In case of a persistent kyphotic posture the soft tissues become shortened in front and the interca•tilaginous surfaces, as well as the osseous vertebra', undergo changes to the extent that the anterior parts become thinner and the posterior parts glow thicker, resulting finally in a decreased flexibility of the spine and producing a rigidity.
Assuming that muscular inactiv ity is the most important and decisive factor in the causation of round shoulders, treatment is easily mapped out.
Our aim should he to methodically strengthen the muscles of the shoulders, back, and pelvis by appropriate gymnastic exercises.
The following simple exercises are recommended: 1. Bending the Trunk Forward and Barkward.—The child assumes an erect position with the hands clasped together across the back. The body is bent forward, then the arms are projected backward with extended elbows and the shoulders are drawn together. Finally, with shoulders and arms held in above mentioned position, the trunk is ually straightened, forcing the spine into a lordotic curve (Figs. G0a, Gob). 2. Breathing Exercises.—The child assumes a position as duced in Fig. 70a. During a forced expiration the arms are brought forward until they are parallel to each other (Fig. 70b). Then while the arms arc carried as far backward as possible, a deep breath is taken (Fig. 70a), and at the same time the child raises his body by standing on his toes.
3. Walking Exercises.—To get children accustomed to an erect posture when walking all exercises must be performed in the attitude reproduced in Fig. 70a.
The amount of work performed by the muscles is best estimated with apparatus recording the resisting power. A simple model which I am accustomed to use is reproduced in Fig. 71. It consists mainly of a rope running over a pulley having at one end two handles and at the other end a weight. The child is seated at a distance of about three feet from the apparatus and assumes an inclined, relaxed posture as reproduced in Fig. 71a. At this stage the weight rests on the floor. The aim of the exercises is to have the child lean far backward, assume a rigid military attitude and simultaneously lift the weight (Fig. 71b), while the elbows are carried upward and backward as far as possible. The apices of the lungs are relieved of the shoulder weight and the inrushing air circulates more freely through the upper pulmonary regions. Both positions as reproduced in Figs. 71a, 71b. must be maintained for at least three seconds to insure an interval between the two parts of the exercise. The weight must be small at first, figuring one-half pound for each year. A child six years old should commence with a three-pound weight. One-half ponmi may be added every t wo weeks. The exercise is performed tinily once or twice for a quarter of an hour. After the exercises an intermission is allowed the atild for rest.