Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs

Owens, L. J.

English

NASA Technical Reports Server

Tibia 
Receivei 
Shoulder 
Rest 
Ba 
Se 
Retai 
Tension in 
Nu 
Bal 
Lockpii 
November 1974
	 B74-10183 
NASA TECH BRIEF 
John F Kennedy Space Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Artificial Limb Connection 
.
	
Artificial Limb Connection
The problem: 
Artificial limbs, or prostheses, have been used by 
amputees for many centuries. At first the prostheses 
were crude, shaped as sticks attached to legs or as hooks 
attached to arms. Recently they have become much 
more sophisticated, incorporating electronic equipment 
and servoriotors to produce more natural limb move- 
ment. With all this development, however, problems 
lary	 still remain in means of attaching prostheses. When 
prostheses are worn for a long time, the harnesses and 
hacrylate clamps create discomforting pressures. This is particularly 
true of the legs supporting the weight of the entire 
body. In addition, the present harnesses are difficult 
and bothersome to connect and disconnect from the 
stumps of amputated limbs. 
The solution: 
A more effective connection has been developed for 
attaching a prosthesis to the remaining stump of an 
amputated limb. The connection simplifies and eases 
donning and removing the artificial limb; eliminates 
leeve	
harnesses and clamps; and reduces skin pressures by 
leceiver allowing the bone to carry all tensile and part of the 
compressive loads between the prosthesis and the 
stump. 
How it's done: 
The receiver of the connection as shown in the 
illustration is implanted by a surgical procedure. One 
part of it is inserted into the bone cavity (medullary 
canal) of the stump. The other part is built into the 
prosthesis. Both ends match and are locked into place, 
forming a very effective union. Then most of the loads 
are transmitted to the bone, as nature intended. 
Specifically, the bone within the stump is exposed, 
and its internal cavity is cleaned to accept the stainless 
steel female receiver. The end of the bone is trimmed to 
fit flush against a shoulder on the receiver. The other 
side of the shoulder supports a vitreous carbon sleeve. 
(continued overleaf) 
This document was prepared under the Sponsorship of the National 	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	
information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19740000183 2020-03-17T13:53:21+00:00Z
This material is biocompatible with the body and the 
skin, allowing the skin to form a hygenic seal around it. 
The receiver is bonded to the inner bone surface with 
methylmethacrylate. To minimize the stress between 
the receiver and the bone and for ease of insertion into 
the methylmethacrylate, the upper end of the receiver 
is tapered and grooved. The receiver is hollow and has 
an annular groove to accept the balls carried on the ball 
lockpin. 
Rancho Los Amigos Hospital, Downey, California has 
designed a molded-plastic socket to custom fit the 
individual's stump. This proven design has been in-
corporated in the connection as shown. 
Because each bone is protected from sharp impacts 
by a softer tissue, the connector includes a coaxial shock 
absorber. The absorber consists of two concentric tubes 
separated with an elastomer to protect the stump against 
shock and vibration. The threaded exterior tube can be 
adjusted to vary the weight distribution between the 
socket (skin pressure) and the connector (the bone). 
Some weight should be supported by the skin to give 
the wearer a more sensitive feeling of his prosthesis. 
Isolators with different properties (i.e., varying the 
elastomer amount and hardness) can be readily inter-
changed as the wearer changes weight or habits.
Custom designs, including cosmetic treatment and 
dimensioning, are determined by a physician who 
considers the amputee's age, sex, build, weight, and 
degree of activity. Because the connection is modular, 
it is easily modified to suit individual needs. 
Note: 
Requests for further information may be directed to: 
Technology Utilization Officer 
Kennedy Space Center 
Code AD-PAT 
Kennedy Space Center, Florida 32899 
Reference: TSP74- 10183 
Patent status: 
Inquiries concerning rights for the commercial use of 
this invention should be addressed to: 
Patent Counsel 
Kennedy Space Center 
Code AD-PAT 
Kennedy Space Center, Florida 32899 
Source: L. J. Owens
Kennedy Space Center
(KSC- 108 33)
. 
B74-10183
	
Category os,06,07


Artificial limb connection

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