Part IIIARTIFICIAL ARMS
The construction of artificial arms may be said to have commenced with the sixteenth century. “The distinguished Chevalier Göetz fought at the head of the army of Margrave Frederick from 1504 to 1562 with an artificial iron hand. The fingers of this hand were closed one after the other by the action of several springs. We are further informed that this hand, which possessed enormous weight, enclosed the stump, and was attached to the armor which covered the body.”
During the sixteenth century many very defective artificial arms were made, which, however, served the purpose for which they were intended, as they enabled the wearers to engage in battle, guide their horses, etc. The artificial hand being once attached to the weapon or bridle rein, mechanism for articulating the fingers was not deemed necessary.
Ambrose Parè, a noted French physician, born in 1500, and called the father of French surgery, describes an artificial hand made of iron, with more perfect mechanism than the one worn by Göetz; in this hand the thumb is immovable and all the fingers are opened and closed simultaneously under the influence of a single spring.
During Ambrose Parè’s time efforts were made to restore natural movements of the lost parts in order to enable the maimed to perform all ordinary labor. Leather, paper, and other metals were substituted for iron. Parè leaves a figure of a leather hand, but without details as to its mechanism; it is apparently made with immovable fingers and thumb, but with a sheath inserted between the thumb and index finger for receiving a pen, etc.He further describes an artificial forearm, which can, by the aid of the sound hand, be brought into any degree of flexion and maintained there by the use of a pawl caught into meshes of a cog wheel. The artificial arms described by Ambrose Parè, although extremely heavy, seem to have been in favor until the latter part of the eighteenth century; at this time a monk of the order of Carmelites designed a hand made of sheet tin, with movable fingers and thumb, to be articulated by movement of the stump, but we are informed that it was too complicated to be used with any degree of success except in cases of amputation near the wrist joint. We have a description of an arm made subsequently of leather and covered with sheepskin, colored in such a manner as to represent the appearance of the human skin, and to make it appear more natural the nails were made of white horn. The improvements in the hand were mostly in the appearance, without any important addition to its utility or usefulness.
In 1818 a Dr. Graefe suggested the construction of an arm susceptible of manipulation by means of cords attached to a corset surrounding the shoulders, the arm to be moved without the aid of the sound hand. This principle of attachment for the movement of the forearm and fingers is followed to the present time with various modifications.
The early history of artificial arms seems to refer mainly to their special construction and application for people of renown who had suffered the loss of their natural extremities. Until a comparatively recent period the impracticability, on account of complicated heavy mechanism, and the great expense of these appliances, precluded anything like a general demand for their use. As the inventivegeniuses of modern times have devised and produced so many labor and time-saving instruments and machines, that are, however useful, nevertheless the cause of much horrible mutilation of humanity, so also have they in some measure made compensation to the maimed by the progress and improvement attained in the utility of the appliances for the substitution of lost members. Simplicity of mechanism, the application of extremely light material in such a manner as to preserve the necessary strength, are the prominent features of progress in artificial arm construction, and in combination with the prevailing moderate prices, bring them into popular favor with those who have use for them.
However light, strong and mechanically perfect an arm and hand may be made, its success or failure—provided the stump is sound and of sufficient length—depends much upon the continued patience and perseverance of the wearer in getting accustomed to its use. The preservation of the form and the general improvement in the appearance produced by a properly constructed and comfortably fitted arm, to say nothing of its usefulness and convenience, should be an incentive to persistent effort on the part of the wearer to habituate himself to it, and if this is practiced for a few weeks there need be no fear of the ultimate result.
For amputation below the elbow the neatest and best fitting socket is made from specially prepared stiff leather moulded over a cast of the stump, supported with a framework of steel and lined with buckskin or kid. The advantages over a wooden socket are that it is less clumsy, adheres more closely to the stump, that there is no dangerof splitting, and withal is equally as durable. We make them, however, of wood if desired. For amputation above the elbow the artificial elbow is made of wood, and it is sometimes desirable to extend the wood upward in one piece to form the socket.
Much has been anticipated and hoped for in artificial limb work from this new and extremely light metal, but it has proved objectionable for any parts in both arms and legs that come in near contact with the stumps, owing to the rapid oxidization that takes place from perspiration, and its practical use is confined to fingers, toes, and such other minor fixtures as are not likely to come in contact with any part of the body.
Whatever their mechanical perfection, artificial hands can, in fact, possess but one useful quality, that of seizing objects like pincers. In nearly every act performed by the natural fingers are combined flexion, extension, prehension, and many other different movements; this combination no mechanic has ever been able—and probably none ever will be able—to successfully reproduce in an artificial hand. It is, therefore, practically useless that the fingers should be movable, since a less complicated, lighter and stronger hand can be made with fingers rigid, in a half-closed, natural position, articulating the thumb only, which results in a more powerful spring and consequently a greater degree of firm grasping power. The fingers being strengthened with steel plates running through them, reinforced with a covering of rawhide, and securely fastened to the hand, heavy objects may be lifted without danger of the fingers straightening out and the object dropping to the ground.
While we furnish the hand with movablefingers, and the rubber hand with ductile rubber fingers, the wooden hand with rigid fingers and movable thumb is recommended as giving the most practical, durable, and satisfactory service.
Artificial hands are covered with a delicately tinted enamel, as nearly a flesh color as it is possible to make; but in order that they may be less conspicuous and the illusion more complete a glove should be worn at all times. We furnish a pair of gloves with each hand.
Tools and implements in almost limitless variety can be used in an arm in place of the hand. Those most frequently used are the plain hook, double hook, ring, knife, fork, brush, and spoon. People who have never worn arms hardly know what will be of service to them. Special tools are required for special work, and these can be subsequently provided when it has been determined what will be most useful. With all arms with detachable hands, or rubber hands with the palm socket, we furnish a plain hook, knife, fork, and brush, without extra charge, or the price of any of these implements that are not wanted will be deducted from the price of the arm.
Usually the fingers for artificial hands are made of a single piece of wood, and it is obvious if the finger is curved or flexed that at some point the grain of the wood will be directly across the finger and will quickly break if subjected to any considerable strain. To obviate this difficulty we make the fingers for the wooden hands of two pieces of wood; on one side the grain or fibre runs lengthwise, and on the other crosswise, and between these two pieces of wood is placed a steel plate, and all are firmly riveted together, the steel plate projectingsufficiently to be securely riveted to the hand. The fingers are next entirely covered with rawhide, which, together with the other precautions taken against breakage, make them sufficiently strong to support the weight of the wearer. See No. 300,page 64.
No. 301 (page 64) represents a stump after partial amputation of the hand, leaving free use of thumb, but it is with difficulty that this can be brought in contact with the remaining stump so as to be of service. No. 302 represents, for stumps of this description, a wooden sheath, terminating in immovable fingers partially closed, the hand being attached to the wrist and forearm by means of a leather lacing attachment. The sheath is covered with rawhide and enameled, and the fingers made as shown in No. 300. Price $40.
Should there be amputation at the base of two or three fingers only, with no impairment in the movements of the remaining one or two, so that they can be brought in firm contact with the thumb, what is left of such a mutilated hand is far more useful than anything that can possibly be made to supplement it, but to conceal the loss and give the hand a more perfect appearance, fingers can be made and applied as represented by No. 302, over which a glove should be worn.
Nos. 303 and 304 (page 64) show an apparatus useful in all kinds of labor for persons who have undergone a partial amputation of the hand. It consists of a leather sheath, laced to the forearm. Attached to the under surface of this sheath is a steel plate, which extends downward under the stump, turning up slightly at the end. At the end is an aperture through which it is possible to slip the handles of tools and implements, passing them beneath the stump, where they are securely held in place by pressure of the stump. Price $20.
300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 316 317
No. 305 represents a stump after an amputation of all the fingers and thumb, and No. 306 an artificial wooden hand for same, with stationary fingers and articulated thumb with a powerful spring to be opened with the assistance of the sound hand. Price $40.
With the assistance of the other hand, or by pressing against some resisting body, the ductile rubber fingers of the hand No. 307 may be changed in position to suit the needs of the wearer as shown by the dotted lines in the illustration. For those who prefer the rubber to the wooden hand it will be furnished with any of the arms we make. It can be attached permanently to the forearm, detachable at the wrist, with provision for using a hook of other implement in place of the hand, or furnished with a palm socket and lock for the use of hook, knife, fork, etc., without removing the hand. See No. 308.
No. 309 represents a new method for connecting the hand and arm. Heretofore the devices in use could not be absolutely relied upon to keep the hand or tools in place. It mattered not how strongly the fingers were made for lifting heavy weights, the customary spring or set-screw used for locking this connection was liable to loosen or give way without warning and cause much annoyance, if not injury. On the hand plate two studs are riveted, the heads of which pass into keyholes in the arm plate. With a slight turn of the hand the heads pass into the slots of the keyholes, bringing the heads of the studs under the arm plate; they are kept immovable with a spring that automatically slips into a slot in the edge of the plate; the spring is released by a pressure of the thumb of the sound hand in twisting the artificial hand off. The hook and other tools have a lug at the end of the spindle or shank; after passing the shank through the hole in the center of the arm plate, it is turned to any desired position and held firmly in place with the wing nut, as shown in No. 310.
318 319 320 321 322 323 324 325
Some of the implements that may be attached in the wrist plate when the hand is removed are also shown in the illustration. All excepting the brush are made of steel, or other suitable metal.
Special knife, fork, brush, and hook will be made for use in the palm of rubber hand, No. 308, without additional charge. Other tools, such as pincers, claw hook, clevis, etc., will be made to order when desired.
These usually leave a stump somewhat larger at the end than immediately above (see No. 318,page 64), thus providing a means of securely applying the arm and keeping it in place without the necessity of attachment above the elbow, as shown in No. 319.
Attachments above the elbow may, however, be put on if thought best, and for amputation at or a short distance above the wrist it is preferable to make the connection at the elbow with leather straps, as shown in No. 320, rather than with steel joints.
The socket of any arm for amputation between wrist and elbow will be made to lace if desired.
No. 321 represents arm for amputation below the elbow, leather socket and leather lacer above the elbow, both reinforced with steel frame, connected at elbow with steel joint straps.
No. 322 is a detachable wooden hand, with rigid fingers and movable thumb. A traction rod for opening the thumb with motion of shoulder is shown in the illustration; a web strap is buttoned to the upper end of the traction rod and passes over opposite shoulder, as shown in No. 326,page 70. Any motion of the shoulder that will draw on this rod will open the thumb, and when the tension is released a strong spring in the thumb brings it back in contact with the first finger. For single amputations there is little or no advantage in having this attachment put on; it necessarily requires more complicated and expensive mechanism, without any practical gain to the wearer. For double amputations something of this kind must be depended upon for assistance, and to obtain the greatest benefit from artificial arms, means similar to this for operating the movement of the thumb are absolutely required. One or more movable fingers in conjunction with the thumb may be operated in the same manner.
Including Plain Hook, Knife, Fork, and Brush
No. 323 represents arm with ball-and-socket wrist joint for amputation below the elbow, but not suitable for an amputation near the wrist for the reason that the space in that locality is required for the mechanism of the joint. In the various uses to which an artificial hand may be put, a change in the position of the hand is often desirable; for example, in keeping a book or paper in position while being written upon with the sound hand, the artificial hand can be turned so that the tips of the fingers will rest upon and hold the article securely in place. In bringing the arm in front of the body the ball-and-socket joint admits of the hand being brought near to the body in a very easy, lifelike manner. In other positions desired the hand may be placed at the degree of flexion most convenient and helpful and that giving the most natural appearance. No. 332, onpage 72, gives an illustration of the details of the joint. The forearm and attachment above the elbow are leather, supported with steel framework same as No. 321. Wooden hand with movable thumb is furnished with or without traction rod for opening thumb with shoulder movement, but no provision is made for the use of a hook or other implement in place of the hand. A rubber hand with palm socket for implements can be attached if preferred, but is somewhat heavier. For persons not employed in laborious occupations and who have no occasionto use a hook or similar implement, this style of arm is desirable; for others we would recommend No. 321.
No. 324,page 66, represents irregularly formed forearm and hand, the forearm being considerably shorter than the opposite one. No. 325 represents artificial arm and hand made to supply the deficiency. The hand may be wood or rubber and detachable or not at the wrist, and provision made for the use of implements the same as in case of an amputation. These malformations are treated mechanically the same as amputations. Plaster moulds or casts of the deformed parts are required, together with measurements of the opposite arm and hand.
No. 326 illustrates arm for amputation below the elbow, equipped with shoulder cap, strap passing around body for holding it in place, and the attachment for opening the thumb by movement of the opposite shoulder. If thumb is to be opened with the assistance of the sound hand, this extra strap and traction rod are omitted.
326
No. 327 onthe next pagerepresents a wooden arm for amputation above the elbow, fitted with cord for raising forearm and locking it at right angles. This is operated as shown in No. 330, while the mechanism is the same as shown in detailed drawing No. 332. Wooden or rubber hand No. 328 is furnished permanently attached or detachable, but this arm may be used as a peg, without hand, hook No. 310 or other implement being used in place of the hand. It can also be made as a peg without a joint at elbow, straight or curved to any desired angle.
Including Hook, Knife, Fork, and Brush
No. 330 represents the corset that is used with arms for upper amputation. The arm is laced or buckled to the corset, and draught cord in the back is for raising the forearm by a shrug of the shoulders.
No. 331 represents wooden arm for amputation above the elbow, with ball-and-socket wrist joint. An explanation of the ball-and-socket wrist for amputation below the elbow is given onpage 69under No. 323. The joint is universal and admits of placing the hand in any position, as shown by dotted lines. This is kept in place by spring friction on the ball. The wrist cannot be made quite the natural shape—that we are able to produce without the ball-and-socket joint; but this must be, necessarily, round. This part, however, is usually covered with the cuff or sleeve and is not conspicuous.
327 328 329 330 331 332 333 334 335
No. 332 is a sectional view of the arm and hand. A forward impulse of the shoulder and stump causes traction of the cord, moving the geared segment wheels so as to raise the forearm to any degree of flexion, when it is retained in position by means of a latch passing through a spring post and locking automatically. The wearer is enabled to conveniently carry a coat, shawl, basket, etc., on the artificial arm. A pressure on the button underneath the arm releases the lock, and the forearm is again under control of the stump and shoulders. The spring in the hand is for keeping the thumb in position and is the same as we put in all hands with movable thumb.
No. 333,page 72, represents one of these useful implements, designed and made expressly for those who have been deprived of the use of one hand, and no such person can afford to be without one for a day. The blade is thin steel, ground to a sharp edge and terminating in a fork. A rolling motion will cut the food, and a twist of the hand will bring the fork into position for use. No. 334 represents a leather sheath into which the knife can be inserted.
No. 335,page 72, represents a simple, serviceable knife that can be operated quickly and conveniently with one hand. A pull of the thumb opens the blade slot, the blade drops down and out and is securely locked; invert the knife, with the blade up, and a pull of the thumb allows it to drop back into the handle.