Chapter 12B - Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles
Special Considerations: Fitting and Training the Bilateral Upper-Limb Amputee
H. Richard Lehneis, Ph.d., C.P.O.
Ruth Dickey, B.S., O.T.R.
This chapter is concerned with the unique problems presented by the bilateral upper-limb amputee. Although it is generally recognized that the unilateral upper-limb amputee uses a prosthesis as an assist and the sound limb for sensory feedback and fine manipulatory activities, the bilateral amputee does not have such a choice. As such, the general principles, preprosthetic training, prosthetic fitting and components, and prosthetic training for the bilateral upper-limb amputee differ distinctly from those recognized in managing the unilateral upper-limb amputee.
The basic objective of prosthetic management of the bilateral upper-limb amputee is to provide the patient with maximum function of the prostheses and residual limbs to be independent in the activities of daily living. Throughout this chapter activities of daily living will be used in the broadest sense to include all aspects of functional skills from self-care to vocational pursuits.
To achieve these goals, independence in donning and doffing the prostheses is a necessity. This requires appropriate harnessing, preferably through interconnecting of the harness systems of both prostheses, and a socket design that enhances ease of donning and doffing.
The need for maximizing the range of motion must be met by choosing appropriate components and socket designs and alignment. Generally, bilateral wrist-flexion units are a must, particularly if independence in personal hygiene is to be expected.
The choice of the terminal device should be, with few exceptions, a prosthetic hook. New amputees rarely appreciate the functional advantages of a prosthetic hook over a prosthetic hand. In these circumstances, it must be explained to the amputee that a prosthetic hook is not an attempt to duplicate the form or function of a hand since it obviously does not look or function like a hand. Rather, the prosthetic hook represents an efficient, built-in tool containing several functions of commonly used tools (e.g., pliers, tweezers). Once the amputee recognizes and appreciates that the hook is not just a poor replacement of a hand, but a tool, often the acceptance of a prosthetic hook becomes somewhat easier.
A major problem unique to the bilateral upper-limb amputee is sensory loss once fitted with prostheses. Whenever possible, fitting and socket configuration for these amputees should be such that the prosthesis can be partially removed for sensory feedback through the residual limb and then reapplied. For example, in a prosthesis with a stump-activated elbow-lock control, the socket may be open ended to expose the distal portion of the residual limb for such purposes. To preserve maximum sensory feedback function, it is of utmost importance that the patient be trained not only with the prosthesis but also in the use of the residual limbs for as many activities as possible. Although not very popular in this country, the Krukenberg amputation should always be considered as an alternative, particularly for blind amputees.
A final, general consideration relates to the strength and safety of prostheses for bilateral amputees. It should be appreciated that the bilateral amputee does not possess the choice that a unilateral amputee does, that is, using the sound limb for most activities and a prosthesis as an assist. Practically all activities must be performed with the prostheses; thus wear and tear on joints and cables are far greater than for the unilateral amputee. This makes it especially important to provide the greatest degree of reliability and safety through the proper choice of strength of material and components in the construction of the prosthesis.
The overall aim of training for the bilateral upper-limb amputee is to provide the maximum degree of independence in all activities of daily living, both with and without prosthetic equipment. The final selection of all equipment for the bilateral amputee, both prosthetic and specially adapted or selected equipment, is based on total needs. Those needs are related to medical status, both diagnosis and prognosis, age, sex, intellectual and psychological functioning, social and cultural values, economic status, and general goals.
Preprosthetic management should include all aspects of care preparatory to but not directly related to the use of prosthetic equipment. The crucial role of this preparatory phase should be strongly emphasized from both the physical and psychological points of view. From this phase, important information will be derived that is necessary for prosthetic prescription as well as patient readiness. The two main areas of management to be discussed are postoperative therapy, which deals with physical care of the residual limb and residual motions, and preprosthetic evaluation, which will establish a baseline of the amputee's current functional level.
Postoperative therapy, begun as soon as possible after surgery, is directed toward the care of the residual limbs and the strengthening of residual motions, which will be used to control the prostheses and substitute for lost motions. Postoperative treatment is carried out by the occupational and physical therapists.
Maximum active range of motion should be achieved in all remaining joints of the upper limbs to provide adequate excursion for operation of prosthetic equipment. In addition, all bilateral upper-limb amputees will need maximum active range of motion of the trunk and lower limbs, particularly at the hip, for flexion and external rotation. For each level of amputation there will be specific exercises related to the parts of the upper limbs to be used for excursion of the prosthetic equipment. For the forequarter amputee, exercises for range concentrate on posture, thoracic mobility, and trunk range. For the shoulder disarticulation amputee, scapular mobility is most crucial. The above-elbow (transhumeral) amputee requires maximum shoulder mobility, and the below-elbow (transradial) amputee requires maximum elbow range and, if possible, maximum forearm rotation. Maintaining and/or increasing range for forearm rotation is vitally important because supination and pronation motions are extremely difficult to incorporate in the prosthesis.
Strengthening is necessary for those motions that are required to power and stabilize prosthetic devices. A total-body strengthening program is also indicated to provide the amputee with adequate strength to function without prosthetic devices. Both isotonic and isometric exercises can be used effectively. Isotonic exercises can be in the form of progressive resistive exercises or manual assistance. Proprioceptive neuromuscular facilitation is a particularly effective approach that enables the therapist to work in diagonal planes, vary the amount of resistance, and key into specific areas of weakness. Isometric exercises are effective in maintaining muscle bulk for stabilization of the arm in the socket of the prosthesis. The stability of the prosthesis depends on both the bulk of the stabilizing musculature and the amputee's ability to voluntarily vary stump configuration. The transhumeral amputee depends on the external rotators and biceps for the stabilization necessary to prevent the prostheses from rotating internally during shoulder flexion and abduction. For the transradial amputee the muscles of supination and pronation are effective stabilizers.
Massage of the residual limbs improves circulation, reduces edema, keeps the skin mobile, prevents adhesions, and begins the toughening process necessary to protect the limb during use. This technique reduces the amputee's fear of having the residual limbs handled.
Maximum shrinkage should occur before fitting the socket. Although shrinkage varies with all amputees, from 2 to 3 months to 1 year or more, with an adequate postoperative program fitting can usually be considered after 2 to 3 months. Elastic shrinkers and techniques using elastic bandages have been found to be successful for shrinking and shaping. The elastic shrinker provides the most consistent pressure; however, caution must be taken so that the shrinker does not slide down the arm and produce a tourniquet effect. On short transhumeral amputations, suspension systems are sometimes required for the shrinker to remain in place. If supervision is inadequate, this is the safest method.The use of an elastic bandage wrapping offers the therapist more control over both pressure and shaping. Wrapping techniques for the short above-elbow limb frequently require use of the opposite axilla. A conical shape is preferred for the transhumeral amputation and a screwdriver shape for the transradial amputation. The latter preserves maximum use of residual rotation. Again, care must be taken in wrapping so as not to produce proximal pressure, which would impair desired shaping, increase edema, and reduce circulation. Residual limb shrinkage using a plaster of paris bandage has also been reported effective when dealing with fatty or edematous stumps. With this method the plaster bandage is applied and suspended from a conventional harness. As shrinkage occurs, new bandages are applied.
Most amputees have phantom sensation, the sensation of the presence of their missing limbs. The hands are usually felt more distinctly and over a longer period of time. Usually the sensation diminishes within a year and generally does not interfere with training.
Phantom pain is felt as cramping, burning, or lancinating. Cramping is frequently relieved by massage, vibration, or electrical stimulation. Burning pain, although uncommon, often requires drug intervention. Much treatment has been unsuccessful. Lancinating pain is most frequently caused by a neuroma and is sometimes treated by cold, vibration, or electrical stimulation. Surgical removal of the neuroma may be required.
Immediate or Early Postoperative Fitting
Immediate postoperative fitting of the upper-limb amputee has come about as a result of the success of this kind of fitting for the lower-limb amputee. Results of both immediate fitting (application of a rigid surgical dressing with a terminal device at the time of surgery or in the immediate postoperative period when the sutures are still in place) and early fitting (application after suture removal) of the prosthetic equipment have been similar to those for lower-limb amputees: (1) reduction in postoperative pain, (2) more rapid prosthetic use (and thereby less dependency for some activities of daily living), (3) good psychological adjustment, (4) reduced postsurgical edema, (5) more rapid limb desensi-tization, and (6) rapid healing. Overall hospitalization time is often significantly reduced.
In both techniques, the amputee has the terminal device mounted in the plaster of paris socket, and the harness system is adjustable for individual needs. As shrinkage occurs, a new socket is fabricated. The difference between the fittings is that the immediate-fitting socket is not removable whereas the early-fitting socket is. With these techniques the training process precedes the fitting of permanent prosthetic equipment. Proponents of these techniques believe that this facilitates the usual necessary adjustments in the harnessing system and design of the trial prosthesis. Also, the amputee learns early the components of the prosthesis and how to use them in activities of daily living rather than initially using adapted devices and then having to change or modify the process when the permanent equipment is delivered.
Another reason for using these early-fitting techniques is to counteract the high rejection rate of prosthetic equipment use that is noted in the unilateral amputee. The longer he relies only on the sound arm for accomplishing functional activities, the less likely is the amputee to make good functional use of the prosthesis.
The most obvious candidates for immediate or early fitting are bilateral upper-limb amputees. This group is the most profoundly dependent in all activities. The sooner some of this dependency can be reduced, the sooner they are relieved of some of their frustration and fear of uselessness. Even the fitting of one limb can be of significant help, especially in allowing some independence for self-care such as eating and toilet care (Fig 12B-1.).
Early Performance of Activities of Daily Living
A program to give the bilateral amputee some degree of independence in activities of daily living should always be initiated early. This can be done in two ways: (1) by beginning to do some activities with the remaining limbs (both upper residual limbs and lower limbs) and (2) by the use of adaptive equipment. This begins to introduce the problem-solving process and decreases feelings of inadequacy and dependency. Principles of special device application are given in the discussion on training later in this chapter.
It is vital to have a coordinated total team effort in the rehabilitation of the bilateral amputee, beginning with the postoperative period and throughout the rehabilitation program. The professional team should consist of the surgeon or physiatrist, prosthetist, rehabilitation nurse, occupational and physical therapists, psychologist, social worker, and vocational counselor. Equally important members of this team are the amputee's family and friends. All the members are required for their particular expertise in providing physical care, equipment, training, future planning, and follow-up. The contributions of both the prosthetist and occupational therapist are specifically discussed in relation to the equipment, treatment, and training in the remainder of this chapter.
Preprosthetic evaluation is completed prior to prescription of the prosthetic equipment. It provides an updated account of the amputee's physical and psychological status, gives information that helps determine further therapy needed, and helps make the proper choice of prosthetic equipment. The occupational therapy preprosthetic evaluation includes the following data:
- Physical status
- Residual-limb descriptors
- Sensory status
- Current status of activities of daily living
- Equipment expectations
PROSTHETIC FITTING AND COMPONENTS
The Bilateral Transradial Amputee
In general, all below-elbow sockets for bilateral amputees should be designed so as to enhance easy donning and doffing, as well as to permit maximum range of residual motion. For wrist disarticulation and the long and medium-length transradial amputation, a conventional socket is indicated with a sufficiently low anterior trim line to permit full range of elbow flexion. Particular attention should be paid to an intimate interface between the residual limb and the socket to take full advantage of any residual pronation and supination. A screwdriver-shaped cross section in the distal area will permit most efficient transmission of residual pronation and supination to the prosthesis. Flexible elbow hinges attached to the triceps pad are required for socket suspension and to permit pronation and supination.
For shorter amputation levels without residual pronation and supination, a socket that encompasses the medial and lateral epicondyles is indicated so that any force applied mediolaterally to the prosthesis will not cause displacement of the socket or at least minimize displacement on the residual limb. Depending on the anticipated activity of the patient, the socket is connected either to flexible hinges and a triceps pad or to metal elbow hinges, either of the single or polycentric type, that are attached to a half cuff. This will reduce socket displacement on the residual limb to a minimum when external loads are applied to the prosthetic forearm. The choice of which elbow hinge to use depends on the residual limb level and the activity of the patient and working environment. Functionally, the shorter the residual limb, the greater the indication for a poly-centric elbow hinge so that prosthetic and anatomic joint congruity can be approached as closely as possible. On the other hand, polycentric hinges are more likely to require frequent maintenance, particularly in certain industrial environments, whereas the single-pivot hinge is sturdier and requires less maintenance.
For the very short transradial amputation, a split socket with the elbow hinges attached to the half cuff is indicated. Although this results in a reduction of force that can be transmitted to the forearm, it is deemed far more important to provide full range of motion. It is, however, possible to increase the forearm lift force by using a split housing so that shoulder flexion and/or scapular abduction help to flex the forearm. In this instance, the residual limb is simply used to stabilize the forearm in the desired degree of elbow flexion. Very short residual below-elbow limbs with limited range of motion and/or hypersensitive areas may be fitted with a stump-activated elbow lock that uses the residual limb to trip a lever that locks or unlocks an external elbow lock hinge. A preferred way of using the stump-activated elbow lock is to adapt the locking lever to a U-shaped configuration that may fit in pressure-tolerant areas, thus avoiding any sensitive areas. A further advantage is that it exposes a larger residual limb area for sensory feedback, especially when the forearm is flexed.
As previously discussed, for the greatest degree of universality of function a hook terminal device is preferred over a prosthetic hand, although a prosthetic hand may be used interchangeably for certain social activities or professions. Many bilateral amputees prefer two different terminal devices to provide a more varied grip, such as a hook with canted fingers on one side and a hook with lyre-shaped fingers on the opposite. Others will utilize an electric hand on one side for its powerful grip and a body-powered hook on the opposite for its versatility.
Bilateral externally powered terminal devices-either hooks, hands, or a combination-have been used successfully. However, body-powered hooks remain the most commonly prescribed devices for bilateral upper-limb amputees because of their light weight, reliability, and versatility.
The type of wrist component indicated depends on residual limb length. For wrist disarticulation and medium-length or long transradial amputations, a built-in flexion wrist may be used. The axis of rotation of the flexion wrist should be aligned so that it forms a 45-de-gree angle with the elbow flexion axis when placed on the prosthetic forearm in the medial-volar quadrant. For high-level transradial amputations when there is no residual pronation or supination, a separate Sierra wrist flexion unit should be installed on a constant-friction wrist. This permits variable angulations of the wrist flexion unit in the constant-friction wrist. When the patient's elbow flexion range is limited, the wrist flexion unit should be installed directly distal to the end of the residual limb. This increases the radius of the flexion arc described by the terminal device in the various flexion positions of the flexion unit, thus increasing the effective range of operation of the terminal device in space. This is especially important for activities near the body midline, such as personal hygiene.
In general, the forearm of all transradial prostheses, but especially those for the bilateral amputee, should be aligned with regard to the socket in such a way that it favors an alignment that brings the terminal device closer to the center of the body and forward and upward. The forward-upward alignment may be as much as 30 degrees to simulate normal elbow flexion alignment in the sagittal plane. The inward (toward the center) alignment should be as much as cosmetically possible. Particular attention should be paid to the very short below-elbow residual limbs because such limbs accentuate the normal carrying angle in the frontal plane. Thus a forearm aligned coincident with the center of a very short residual limb would fall way short in bringing the terminal device toward the center of the body and thus would greatly diminish the function of the prosthesis, particularly with regard to personal hygiene.
Harnessing for the bilateral transradial amputee is rather simple. Both prostheses are usually interconnected by running the control attachment strap to the front support strap of the opposite prosthesis. They are sewn together in the center line of the back, or they may run to a center ring. Alternatively, some amputees prefer that each arm be harnessed independently so that they have the option of wearing only one prosthesis on occasion.
The Bilateral Transhumeral Amputee
The medium-length or long above-elbow residual limb may be fitted best with a low lateral socket wall such as developed by McLaurin. The anterior and posterior wings of the socket should extend sufficiently to stabilize the prosthesis against axial rotation. Angulation osteotomy of the humerus, as developed by Mar-quardt, gives the best rotational control. Internal or external rotation of the humerus is thus transferred most effectively to the prosthesis. In this case, the socket proximal trim line can be considerably shorter than in the conventional design. The shorter the amputation level, the higher the socket trim line must extend, particularly the posterior and anterior wings. This is necessary to provide adequate control against longitudinal rotation as well as to provide suspension.
As previously discussed, if wrist flexion units are used, they should be of the Sierra type. The built-in flexion wrist does not provide sufficient range of motion for the same reason described for the short transradial unit. The choice of a terminal device is similar to the transradial case, as previously discussed, although the impact on the elbow unit selected must be carefully considered. Conventional elbow joints with alternating locks and a friction-controlled turntable for internal-external rotation are standard components to be used. A humeral rotation lock may be indicated when positive locking of internal and external rotation of the elbow and forearm on the humeral section is required for certain vocational and avocational tasks. Although many levels of transhumeral amputations may be fitted with prostheses with dual control cables, the short and very short levels generally do better with some externally powered components to reduce the effort required to operate the prostheses. Electric elbows, electric hooks or hands, or a combination of both are feasible. As previously discussed, body-powered hooks (at least on one side) are preferred due to their versatile grasp and reliability.
Normally, no deviation from standard alignment is necessary; however, when excursion is limited, alignment of the forearm and wrist unit similar to that described for the transradial amputee will enhance function. Another alignment consideration is for those amputees who are wheelchair users. In this case, the length and alignment of the humeral section should be such as to be compatible with the armrests of the wheelchair. In all other cases, whenever the length of the residual limb permits, the humeral section should be lengthened and the forearm section shortened while retaining the overall desired length. This shortens the distal lever arm, thus bringing the center of gravity of the forearm closer to the elbow and reducing the force required to flex the elbow. Such a differential in forearm length from the normal is approximately 3 to 4 cm. Any further reduction of the forearm length would diminish the ability of the patient to reach all facial and head areas.
The principle of harnessing the bilateral transhumeral amputee is similar to that described for the bilateral transradial amputee, that is, the control attachment strap of one prosthesis is connected to or serves as the front suspension strap of the contralateral prosthesis, thus ensuring independence of control. The elbow control strap and the lateral suspension straps are attached in the conventional manner.
Bilateral Shoulder Disarticulation
This amputation level is best served by the use of externally energized prostheses such as a myoelectric or switch-controlled electric elbow or terminal device (Fig 12B-2.,A-D). It should be noted that some clinicians and amputees are willing to sacrifice a certain amount of function as a trade-off for the simplicity and lighter weight afforded by conventional prostheses.
If the patient is to be fitted with functional prostheses bilaterally, the conventional shoulder disarticulation socket configuration is indicated. If, however, only one side is to be fitted with a functional prosthesis and the contralateral side is to be used as an anchor for harnessing, a much smaller socket configuration on the control side may suffice.
Indications for the various components are the same as those described for the bilateral transhumeral amputee. Various passive, free, or friction-controlled shoulder joints are available. Those that provide motion about at least a shoulder abduction axis are indicated. If, additionally, a shoulder flexion joint is used, it must have a 180-degree extension stop to prevent shoulder hyperextension.
Other than the shoulder joint, alignment of the bilateral shoulder disarticulation prosthesis is identical to that described for the bilateral transhumeral amputee. Alignment of the shoulder joint should be such that the flexion axis is skewed internally with respect to the frontal plane, that is, it should form an angle of 30 degrees with respect to the sagittal plane.
Control harnessing for functional bilateral shoulder disarticulation amputees requires great care. The control attachment straps should be attached somewhat superior to the posteroinferior border of the socket so that they cross each other at an angle; otherwise they may get caught on one another during operation. Furthermore, inadvertent operation may result the closer the control attachment straps approach a horizontal matching alignment. An elastic cross-back strap connecting the posteroinferior corners of the socket and a nonelas-tic chest strap are required to stabilize the sockets against each other and to provide an intimate interface between the socket and the patient. The front support straps are also attached to the posteroinferior corners of the socket.
Bilateral forequarter amputees are best managed prosthetically through the use of external power, although some function may be obtained through the fitting of conventionally controlled prostheses through the use of perineal straps and nudge controls for the elbow locks. Mixed bilateral upper-limb amputation levels must be treated by combining the fitting principles described for the various levels of amputation.
As previously stated, the overall aim of prosthetic training for the adult bilateral upper-limb amputee is to provide the maximum degree of independence in all activities of daily living, both with and without prosthetic equipment. The bilateral upper-limb amputee depends significantly more on prosthetic and other assistive/adaptive devices and the ability to skillfully use residual body parts and motions. Therefore a framework for skill acquisition is recommended. In following such a framework, there is no intent to force the amputee into a rigid premeditated program. On the contrary, it has proved to be a highly successful means of teaching the basic skills of prosthetic control, as well as providing a logical means of meeting the specific needs of each amputee. Although a certain amount of trial and error is necessary, a framework reduces unnecessary frustration, time, and energy. Both the amputee and therapist have clear guidelines for monitoring progress and establishing ongoing goals.
The training period provides time for ongoing evaluation of prescribed prosthetic and assistive devices from a mechanical and functional point of view. A sound liaison between the prosthetist and occupational therapist permits an exchange of information about functional performance with the prosthesis and allows time for revisions, if necesssary. Re-evaluation by the entire team should occur periodically.
Mention should be made of the importance of a positive working relationship between the amputee and the therapist. Training for the upper-limb amputee requires the best possible collaboration of trainer skill and ingenuity and amputee motivation and ingenuity. The therapist must identify those interests and needs that will create motivation to learn in the amputee. The therapist's ability to motivate the amputee directly and to explain the importance of training related to individual needs is crucial for building successful cooperation.For the adult, motivation usually depends on one or more of the following: a desire for independence in activities of daily living; cosmesis, especially that related to social and/or vocational activities; securing or returning to employment; and participation in leisure time activities.
The therapist must have full knowledge of current prosthetic equipment, control motions of operation, and mechanical and functional characteristics of components. This should be combined with a sound background in upper-limb anatomy and kinesiology. Much of the actual training is identical to that of the unilateral amputee, and the therapist should be familiar with those principles and techniques. Also necessary are skills in practical problem solving and a knowledge of factors that affect learning.
The amputee should continue a general conditioning program concurrent with any other treatment and prosthetic training. The general conditioning program should continue until such time as the use of prosthetic and other equipment and the use of residual body motions for daily needs can maintain that same conditioning. If the amputee is largely accomplishing the functional activities of dressing, grooming, personal hygiene, and eating, those needs are probably being met.
The process described includes four areas of training necessary for the transmission of basic information, acquisition of the skills of prosthetics operation, and methods to deal with special needs. Only the process itself will be defined and outlined; no attempt will be made to provide step-by-step instruction in the techniques themselves. The four areas of training are orientation and initial checkout, controls training, skills training, and functional activity.
Orientation and Initial Checkout
A clear explanation of the amputees training needs should be given, goals should be identified and/or reviewed, cooperation elicited, and mutual goals set. As a result of the fitting sessions during fabrication of the prostheses, the amputee is often somewhat familiar with the equipment before beginning training. The therapist, however, should not assume this.
Since much of the training will be difficult and sometimes frustrating, the need for maximum-functioning prosthetic equipment is increased. Therefore an initial checkout of the equipment for fit and function is completed at the time of delivery to ensure maximum comfort and mechanical operation. The checkout of fit includes an evaluation of optimum harnessing system placement and socket comfort and fit. Mechanical function checkout evaluates range of motion, cable system operation, control system efficiency, wrist and wrist flexion unit operation, and terminal device operation. Factors are more often identified during the training process since they relate to the kinds and amounts of stress each amputee develops in using the equipment. Any changes that might increase mechanical function should be completed before proceeding with prosthetic training. Checkout of an informational nature should be an innate and ongoing part of the training. Major changes, of course, require more formalized checkout.
Instruction in the nomenclature of the equipment is begun during the orientation and frequently reviewed so that the amputee becomes familiar with the specific terminology necessary for discussion of the equipment. This will ultimately be most important when making appointments for adjustments or repairs. Instruction is also accomplished in the "dos and don'ts" of physical care of the prostheses. Often the terminology and care instruction can be given together.
Instruction in skin care provides the amputee with information regarding the need for and the kind of protection from the prostheses and harnessing system the skin will require to prevent irritation and pressure. This includes residual limb and skin hygiene and padding requirements for protection and perspiration absorption. Areas of potential pressure and irritation are defined. Directions for general visual examination of the residual limbs and other potential areas of irritation are given to all amputees, as well as specific directions for situations in which sensory impairments prohibit total feedback.
Written instructions referring to specific needs are provided, along with pictures (line drawings) illustrating nomenclature, skin care, and prosthetic equipment. Both written and verbal data should be provided in a language that is easily understood. This may require the use of an interpreter for trainees whose preferred language differs from that of the clinician.
Controls training entails teaching methods of donning and doffing the prostheses and the control motions required for prosthetic equipment operation. This phase of training, although closely connected to and often combined with skills training, is treated separately for the bilateral amputee. This is because he typically needs to learn the more complicated control motions associated with either cross-controlling harnessing systems or two control systems necessitated by mixed levels of amputations. Full concentration is given to teaching necessary body control motions with minimal exaggerated motion and energy expenditure. Auditory and visual cues substitute for a loss of or limitation in the availability of sensory feedback (see Chapter 6D).
Transradial Amputees.-Donning and doffing are accomplished by using one of two methods: either over the head or coat application. Removal is accomplished so as to place the prostheses in position for redonning.
Controls training for terminal device operation in space requires shoulder flexion and scapular abduction for both single and dual control systems. Passive pre-positioning is needed for control of the wrist unit and wrist flexion unit.
Transhumeral Amputees.-Donning and doffing are accomplished by a modified method using additional support and stabilization under the elbow. Doffing again places the prostheses in position for redonning.
Controls training for terminal device operation and control of elbow motion and the elbow mechanism is shoulder flexion and scapular abduction. For elbow lock it is shoulder depression, extension, and abduction in a dual control system. Terminal device operation in space requires skillful use of the elbow locking-unlocking mechanism, a control often requiring increased practice for skill, reliability, and efficiency. Auditory feedback can be specifically helpful in the training for use of the elbow lock mechanism. Passive prepositioning is needed for wrist rotation, wrist flexion, and elbow rotation.
Shoulder Disarticulation and Forequarter Amputees.-Donning and doffing require a supporting surface for stabilization both when positioning the thorax in the prostheses and while fastening the chest strap. External adaptations are frequently required for attaching the strap because of the size, weight, and reduced reaching range of the prostheses. Doffing requires a support surface to stabilize for chest strap release and for placement for redonning as previously described.
Control motions for shoulder disarticulation for terminal device operation and control of elbow motion is scapular abduction. Elbow mechanism control with a waist strap is scapular elevation, with a perineal strap, by trunk elevation, or with a chin nudge. Passive prepositioning is needed for wrist rotation, wrist flexion, elbow rotation, and shoulder motions.
Forequarter prostheses offer such little functional replacement that external power becomes mandatory.
The time necessary to learn control motions varies significantly from individual to individual. Some learn the controls in the first few minutes after donning the prostheses, whereas others require concentrated practice. Progression to skills training does require a general degree of reliable terminal device operation, elbow control, and prepositioning ability with minimal energy expenditure and exaggerated use of either the body or prostheses. The refining of these motions can be accomplished as training proceeds. Ultimately the decision to move into that phase is made by the therapist.
The criterion for skillful use of the prostheses is to achieve as nearly normal function as can replicate normal limbs doing similar activity. The third phase of training incorporates the amputee's previously learned control motions, skill, and functional understanding of the prostheses with the principles of proper prepositioning and object stability. This can be accomplished by using training devices geared for increased difficulty and specific skill acquisition. Practice focus changes from concentration on the control motions themselves to control motions for purposeful static and dynamic positioning, prehension, and manipulation. The use of training devices allows this practice while separating achievement of quality performance from the completion of functional activity. Very often the amputee attaches too much initial importance to the skilled accomplishment of functional tasks and when unable to meet those expectations feels defeated and discouraged. The use of training devices permits sequential building and mastering of skills for easier transition to functional tasks.
Correct terminal device prepositioning is the key to successful use for functional activity. For the bilateral amputee this requires passive positioning of both the wrist unit for supination and pronation and the wrist flexion unit to allow positioning close to the body for self-care. Prepositioning is accomplished by using the body or other objects in the environment or with the opposite prosthesis. The number and kind of drills used are specific to individual need. Most drills are directed initially toward learning the principles of approach, grasp, and release.
For the majority of bilateral amputees, the prostheses are interconnected by their harness systems so that motion in one system produces motion in the other. Specific training is directed toward adjustment of body position to prevent inadvertent overflow between systems (Fig 12B-3.). The importance of this is most obviously seen in the use of one prosthesis in a static holding position while using the other dynamically.
Dominance is usually established in the limb with the most residual motion. Unless there are complications, in limbs of equal length dominance remains with the preferred limb. An exception to this may be the individual with exceptional skill who chooses to use a much shorter, but preferred limb rather than to change dominance. Choice of dominance is usually made when the amputee is performing activities without the prostheses; however, if no preference is shown, the skills training usually establishes dominance.
The beginning of the bonding of skillful prosthetic control with functional activity is based on the readiness of the amputee. General guidelines for determination of readiness can be established by observing how skillfully the principles of use are applied, the normalization of body motions, the time necessary to complete a task, and the amount of energy being expended. Also to be considered in making this determination is when the control motion execution is more automatic and secondary in the amputee's concentration. The therapist's skillful choice between devices for learning skills vs. those for learning functional tasks helps the amputee view progress more clearly and decreases frustration.
Functional training in activities of daily living can begin soon after basic skills have been achieved. Alternation between both types of activities bonds the functional task and skills more quickly, principally by permitting immediate feedback. Although functional training in activities of daily living has been going on concurrently in alternative forms, the initiation of these activities with prosthetic equipment focuses anew the importance of considering the needs and goals of the individual.
Certainly, it would be impossible in a training period to accomplish all the activities that would be needed by the amputee from that day forth; however, with bilateral amputees, it is often necessary to cover more of the actual activities, especially those requiring special techniques or adaptive equipment. Tasks that most notably decrease the amputees dependence on others for personal care should be initiated first. The following list includes a general order of the sequence and areas of focus for activities of daily living:
- Self-care.-Eating, grooming, dressing, bathing, and personal hygiene.
- Communication skills.-Writing; telephone use; operation of recording devices; handling books, magazines, papers, etc.; typing; and general office skills.
- Homemaking.-Cooking, cleaning, washing, ironing, general housekeeping chores, and baby care.
- Social skills and avocational interests.-Evaluation of the pursuit of former interests and exploration of new interests; social skills that relate to the individual's life-style and interests.
- Prevocational and vocational exploration.-Evaluation of skills in relation to previous work and/or exploration of new vocational possibilities. As skills improve, the vocational counselor will be able to more accurately assist in this phase. Follow-up as relates to the job may be necessary for adaptations and/or general work setup.
- Mobility.-Driving and the use of public transportation.
The use of a checklist is recommended to ensure that all areas of necessary and desired training have been covered. A final checkout on completion of training provides discharge information on equipment, fit, and function. It is recommended that a final checkout accompany the summary of final function, special devices provided, and recommendations for follow-up.
Almost without exception, all bilateral upper-limb amputees require some special selection of existing equipment and/or the adaptation of devices to meet their needs, both with and without prosthetic devices. Training would be incomplete without a more specific discussion of the role of assistive/adaptive equipment.[*Assistive/adaptive equipment is "a special device which assists in the performance of self/care, work or play/leisure activities or physical exercise." (From the American Occupational Therapy Association official glossary, January 1976.)] Assistive/adaptive equipment is provided with the same basic considerations as previously discussed for the selection of prosthetic equipment: medical, psychological-intellectual, social, and economic status. Over the years the old trial-and-error methods have given way to more sophisticated application of devices due to advances in the following areas:
- Evaluation techniques used to analyze motions both of normal activities and individual functions
- Increases in technical development of devices, both mechanical and electronic
- Increased availability of commercial devices to meet varied needs
- Increased sophistication of materials used in device construction
With regard to all of these considerations, the occupational therapist must have knowledge and skill in the following areas as they relate to device application and construction:
- Evaluation is conducted in two ways: (1) by the analysis of normal motions and forces involved in the activities of daily living and (2) the evaluation of individual limitations through a functional motion test. Thus by knowing the motions required for a specific task it is possible to take into account individual limitations and determine what activities will require assistance and/or substitution.
- The therapist must have an awareness of commercially available equipment, both adapted or specifically suited to meet individual needs. Prefabricated equipment or component systems frequently save significant time and money for the patient and allow the therapist time to devote to other problem-solving needs that cannot be met by commercially constructed devices. Figure 12B-4 shows parts of the Universal component system that can substitute for a loss of hand function.
- A knowledge of how to design, construct, and fit adapted devices for individual needs is necessary when commercial devices are either unavailable or too costly. Training the patient in the use of special devices requires knowledge of the mechanical operation of the device itself and control motions required by the patient. The therapist must also be skilled in troubleshooting and problem solving.
- Finally, the therapist must be able to estimate potential for device use based on psychological and social factors.
All of these areas apply to devices in general. For the bilateral amputee, the therapist must apply the principles both with and without prosthetic equipment. This requires the therapist to be fully aware of the functional abilities of both the individual and the prostheses.
The principles of motion economy and energy conservation apply to the execution of all activity for environmental organization and individual task setup. A good general guideline to follow is an arrangement whereby maximum independence is achieved with the least amount of time, number of steps, energy expended, and equipment necessary.
The use of electronic technology in rehabilitation has added another dimension in devices to increase independence for the very severely disabled amputee through systems devoted to environmental control. Through these environmental control systems it becomes possible to operate various appliances (lights, telephone, alarm systems, intercom, television, electric bed controls, door locks and openers, drapery pulls, etc.) in a living or work area by using residual control motions to operate sensitive microswitches, pneumatic switches, or voice-actuated controls.
- Bailey RB: An upper extremity training arm. Am J Occup Ther 1970; 24:5, 357.
- Bender LF: Prostheses and Rehabilitation After Arm Amputation. Springfield, Ill, Charles C Thomas Publishers, 1974.
- Friedman LW: Rehabilitation of amputees, In Licht S (ed): Rehabilitation and Medicine. New Haven, Conn, S Licht Publisher, 1968.
- Gullickson G Jr: Exercise for amputees, in Licht S (ed): Therapeutic Exercise. New Haven, Conn, S Licht Publisher, 1961.
- Laughlin E, Stanford JW, Phelps M: Immediate postsurgical prosthetics fitting of a bilateral below elbow amputee, a report. Artif Limbs 1968; 12:17.
- Reyburn TV: A method of early prosthetics training for upper-extremity amputees. Artif Limbs 1971; 15:1.
- Santschi WR, Winston MP (eds): Manual of Upper Extremity Prosthetics. Los Angeles, University of California School of Medicine, 1958.
- Sarmiento A, McCollough NC III, Williams EM, et al: Immediate postsurgical prosthesis fitting in the management of upper extremity amputees. Artif Limbs 1968; 12:14.
- Upper-Extremity Prosthetics. New York, New York University, Post-Graduate Medical School, Prosthetics and Orthotics, 1971.
- Zimmerman ME: Analysis of adapted equipment, Part II. Am J Occup Ther 1957; 11:4.
- Zimmerman ME: The functional motion test as an evaluation tool for patients with lower motor neuron disturbances. Am J Occup Ther 1969; 23:1.
- Zimmerman ME: The role of special equipment in the rehabilitation of the injured spinal cord, in Cull JG, Nardy RE (eds): Physical Medicine and Rehabilitation Approaches in Spinal Cord Injury. Springfield, Ill, Charles C Thomas Publishers, 1977.
Chapter 12B - Atlas of Limb Prosthetics: Surgical, Prosthetic, and Rehabilitation Principles