The Evolution of Upper Limb Prosthetic Socket Design

Well thought out socket designs and careful consideration of residual limb presentation set the stage for patient success—maximizing range of motion, providing stability throughout daily activities, and comfortably distributing the forces exerted on the residual limb during movement and suspension. In contrast, poor socket design will often drive people to abandon the prosthesis because many patients have an intact arm or hand. The foundation for all prosthetic procedures is a well designed and considerate prosthetic socket. The purpose of this article is to shed light on the many variables behind the evolution of upper limb socket design. Review of historical literature reveals two distinct and major influences—material science and the emerging upper limb prosthetic specialist. (J Prosthet Orthot. 2008;20:85–92.) KEY INDEXING TERMS: upper limb, prosthesis, prosthetic socket, evolution of socket design, prosthetic material science, upper limb prosthetic specialist One of the single most determining factors of whether a person will use a prosthesis is prosthetic socket design. In the words of Hepp “the degree to which the prosthesis fits the stump will make all the difference.” Well thought out socket designs and careful consideration of residual limb presentation sets the stage for patient success—maximizing range of motion, providing stability throughout daily activities, and comfortably distributing the forces exerted on the residual limb during movement and suspension. In contrast, poor socket design can drive people to abandon the prosthesis because many patients have an intact arm or hand. Clinically, this decision becomes detrimental years later when repetitive stress syndrome compromises the remaining natural limb, causing pain and loss of function. Other causes of prosthesis abandonment include functionality of componentry, weight, and time to fitting and follow up. Irregardless of the cause, prosthesis abandonment is a serious problem that should be avoided whenever possible given the likelihood that repetitive stress syndrome may develop in individuals that rely heavily on one arm for daily tasks. The foundation for all prosthetic procedures is a well designed and considerate prosthetic socket. The purpose of this article is to shed light on the many variables behind the evolution of upper limb socket design. Review of historical literature reveals two distinct and major influences—material science and the emerging upper limb prosthetic specialist. A HISTORICAL PERSPECTIVE Ironically, as this article was being researched and written, the author was reminded of a grade school oral report he had presented 25 years earlier on Ambrose Pare. Pare’s discoveries, which revolutionized amputee care, remain relevant for both school children and medical professionals. During Pare’s time, doctors cauterized gunshot wounds with boiling oil. It was not until Pare ran out of oil in a battle that he began to use simple dressings and soothing ointments that resulted in a marked improvement in his patients. Pare’s advances in wound care helped more amputees survive. He also discovered that ligation of blood vessels controlled bleeding during amputation. Pare went on to conceptualize many different orthotic and prosthetic designs for both upper and lower limbs. Up until 1900, most references to upper limb prosthetics is found in literature relating to warfare and similar conflict. Then in 1905, Marks made an important observation. He observed that the demand for upper limb prosthesis had grown with the emergence of early 20th century industry. He noted the increases in limb loss with the transition from black powder to dynamite, from horse-cars to electric trolley, and from the scythe or cradle to the mowing machine. Not until the mid 20th century does discussion of socket design crop up in upper limb prosthetic literature. Hepp seems to be the first to state the importance of a correctly fit socket and how this issue had been ignored for upper limb patients despite the fact that clinicians had long focused on socket design for lower limb amputees. This concurs with this author’s review of pre-1900 prosthetic literature. Hepp’s comments were likely the starting bell that began the push toward better fitting upper limb sockets. Hepp states that: “if the socket fits firmly and well on the stump, there is little or no strain on the harness when the prosthesis is used to carry or hold various articles. If the socket fits well and is pressed firmly to the stump, it will effectively withstand any pressure and transmit force against any object and at the same time transmit force from parts of the harness to the mobile parts of the prosthesis. Should the socket be without any rotary motion or fitted so well that the possibility of ridges developing in the stump be eliminated, then the danger of pseudoarthosis between the socket and stump is reduced to a minimum and every movement of the artificial CHRIS LAKE, CPO, FAAOP, is affiliated with the Advanced Arm Dynamics, Irving, Texas. Disclosure: The author declare no conflicts of interest. Copyright © 2008 American Academy of Orthotists and Prosthetists. Correspondence to: Chris Lake, CPO, FAAOP, Advanced Arm Dynamics, 3501 North MacArthur Blvd, Suite 650, Irving, TX 75062; e-mail: [email protected] 85 Volume 20 • Number 3 • 2008 arm in the region of the stump can be purposefully made when performing rough or exacting work. An anatomically correct fitting gives the amputee a feeling that his artificial arm is really a part of his body.”