The Myoelectric Myth

By Bill Baughn

For more than fifty years pediatric upper extremity prosthetics have been practiced based, not on scientific knowledge or the knowledge gained through patient follow-ups, but on the unfounded assumptions of two-handed clinicians. They assume the need, and they assume the benefits.

Scientists have always been concerned about whether or not they can do something. Rarely do they give any thought to whether or not they should do something. C. P. Snow writes, “Scientists regard it as a major intellectual virtue, to know what not to think about.”

Child amputee clinics have been operating in this country for more than forty years. None have ever done a study that I can locate, to determine if the one out of ten upper extremity patients who continue to use their prosthesis into maturity enjoy any social, financial, emotional or functional benefits, over the nine patients who don’t. The premise that all upper extremity amputees need a prosthesis and will benefit from its use is accepted without question, despite the fact that over eighty percent of all arm amputees, both traumatic and congenital, show their disagreement by discarding their prosthesis. How can prostheses be prescribed as the only option without credible, scientific evidence which shows some benefit to the child or some functional need which can be met with a prosthesis?

A very young child does not consider that having only one hand is in any way extraordinary. He will discover that he has only one hand and the rest of his family have two and he may remark on it or ask why, but he will not be upset by it. To him it is the same as some people are tall and others short, or some people having no hair or others wearing glasses. It is a difference but has no other significance to him. It is only when he discovers that other people think that it is odd that it begins to affect him. Then, if he is confident that it does not affect how his parents feel toward him, he will learn to accept it and gradually realize that he has a right to be different.

The practice of fitting these children as early as possible–at eight weeks according to some–is not designed to meet any need on the part of the child. It is designed to create a need, to make the child dependent on an artificial device that most could do as well or better without. Ninety percent of these attempts are failures: what is the cost to the child’s emotional well-being?

For its manipulative ability the hand relies on sensation and dexterity. Without sensation dexterity cannot exist, but with sensation one needs remarkably little dexterity to achieve a high degree of manipulative ability. The limb-deficient child has this sensation. He has the same precise sensation in the end of his incomplete arm as we have in the tips of our fingers. The high degree of sensory discrimination present in the distal end of the congenitally shortened limb makes the wearing of any prosthesis irksome and could be likened to covering the hand with a boxing glove.

The child with one prosthesis is more tolerant of its shortcomings because he is less dependent on it. The child with two or more prostheses will not tolerate wearing prostheses that restrict his function. If he is not allowed to discard them he will show his frustration by psychological disturbance. ₍₁₎ Learning and understanding are markedly impaired unless sensory stimulation occurs. A child cannot learn the nature of surfaces–weight, size, and resilience–unless the appropriate feelings are stimulated early enough. The shape of objects may not be fully understood without appreciation of its form by the sense of touch. ₍₂₎ The child without specific sensory training is learning about the world through tongs, so to speak. The prosthesis isolates the child from the world through its failure to transmit sensation. ₍₃₎

A prosthetist has made claim to have developed a prosthetic hand with “the sense of touch”. When a child can put his prosthetic hand through a hole in a box and tell us he has found a kitten, that the kitten is warm and furry, that it is licking his hand and his tongue is rough and wet, then and only then will it be honest and ethical to use such a term. Until then it is a fraud designed to enrich the prosthetist.

The course of treatment for child amputees is not designed for the child but for the parents. The first instinct of a parent who has a child with a part missing is to have that part replaced. This is quite natural, and it is easier for the rehabilitation industry to accede to the parents’ demands than it is to deal with their real needs, which are emotional and psychological. If rehabilitation centers had knowledgeable psychologists and adult congenital amputees who could help the parents understand that their child can become a happy, productive adult with or without a prosthesis, that the love and approval of his family will impact the child’s future far more than any artificial device, more of their graduates would be free of meaningful limitations.

Child amputee facilities should maintain contact with their patients throughout their lives. If ninety percent choose to function without prostheses it’s just possible that the professional community should recognize that being born with a limb defect doesn’t impair the mind, that they can learn more from their patients than they can from each other.

The goal of rehabilitation should be to help the patient live as naturally as possible. If the patient can function as well or better without carrying around an artificial device, why would anyone who has the patient’s best interest at heart expect him to do so? Non-prosthetic skills are not dependent on the integrity of cables, harnesses, rubber bands, batteries and motors. And, non-prosthetic skills are available twenty four hours a day, in the swimming pool, in bed and in the bathtub.

Today, rehabilitation facilities are paid for time spent with the patient and for devices provided whether they are effective or not. If, instead they were paid on the basis of the patient’s functional achievements adult amputees couldn’t handle all the calls from professionals wanting to learn what works.

Child amputees should be fitted with prostheses–but not until they can communicate and participate in the fitting and training processes. Research should continue–because someday we will develop effective, sensate devices–but experimental devices should be tested on adult amputees who are able to use and evaluate them, not foisted on helpless infants and declared a success.

(1) Robertson, E.: Rehabilitation of Arm Amputees and Limb- Deficient Children. London , Bailliere Tindall, 1978, pp. 135

(2) Marquart, E. G. : “The Total Treatment of the Limb-Deficient Child” Rehabilitation Monograph No. 44, Institute of Rehabilitation Medicine, New York University Medical Center , 1969.

(3) Kinner-Wilson, A.B. : “Specifications of a Loss”. In Murdock, G. : Prosthetic and Orthotic Practice. London , Edward Arnold Publishers, 1970.