Featured Research

from universities, journals, and other organizations

New Surgical Technique Shows Promise For Improving Function Of Artificial Arms

Date:
February 14, 2009
Source:
JAMA and Archives Journals
Summary:
A surgical technique known as targeted muscle reinnervation appears to enable patients with arm amputations to have improved control of functions with an artificial arm, according to a new study.

A surgical technique known as targeted muscle reinnervation appears to enable patients with arm amputations to have improved control of functions with an artificial arm, according to a new study.

Currently available prostheses following upper-limb amputation do not adequately restore the function of an individual's arm and hand. The most commonly used prostheses are body-powered, which capture remaining shoulder motion with a harness and transfer this movement through a cable to operate the hand, wrist, or elbow. With this control method, only one joint can be operated at a time, according to background information in the article.

Improving the function of prosthetic arms remains a challenge, because access to the nerve-control information for the arm is lost during amputation. With the surgical procedure, targeted muscle reinnervation (TMR), remaining arm nerves are transferred to chest or upper-arm muscles that are no longer biomechanically functional due to loss of the limb. The goal of this procedure is to improve control of prostheses that use electromyogram (EMG) signals (the electrical signals generated during muscle contraction) from residual limb muscles to control motorized arm joints. Once reinnervated (restore nerve function), these muscles provide physiologically appropriate EMG signals for control of the elbow, wrist, and hand. It is unknown whether reinnervated muscles can stably and accurately provide myoelectric (electrical impulses in muscle) signals for real-time control of multifunction prostheses.

Todd A. Kuiken, M.D., Ph.D., of the Rehabilitation Institute of Chicago, and colleagues assessed the performance of five patients with upper-limb amputation who had undergone TMR surgery. The study, conducted between January 2007 and January 2008, also included 5 control participants without amputation. All participants were instructed to perform various arm movements, and their abilities to control the virtual prosthetic arm were measured.

The average motion selection times for elbow and wrist movements (elbow flexion/extension, wrist rotation, and wrist flexion/extension) were 0.22 seconds for TMR patients and 0.16 seconds for control participants. The average motion completion rate for elbow and wrist movements was high (96.3 percent for TMR patients and 100 percent for control participants). The average motion completion times for elbow and wrist movements were 1.29 seconds for TMR patients and 1.08 seconds for control participants. For both groups, hand grasps took longer to complete than arm movements; the average motion completion times for hand grasps were 1.54 seconds for TMR patients and 1.26 seconds for control participants.

Three of the patients were able to demonstrate the use of the control system in advanced prostheses, including motorized shoulders, elbows, wrists, and hands.

"These early trials demonstrate the feasibility of using TMR to control complex multifunction prostheses. Additional research and development need to be conducted before field trials can be performed," the authors write. "The prosthetic arms tested in this study performed very well as early prototypes. Further improvements are needed and have been planned, including reducing the size and weight and increasing the robustness of these advanced prostheses."

Editorial: Taking Control of Prosthetic Arms

In an accompanying editorial, Gerald E. Loeb, M.D., of the University of Southern California, Los Angeles, comments on the findings regarding the use of TMR.

"Kuiken et al have reported on an exciting and promising work in progress, with many opportunities available to improve both the technology and the clinical implementation. Such revolutions develop slowly at best, but their effects tend to be profound. With increasing functional capabilities, patients with upper-extremity amputations may derive exceptional benefit from prosthetic arms, just as legions of patients with lower-extremity amputations now lead remarkably normal and even athletic lives."



Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Todd A. Kuiken; Guanglin Li; Blair A. Lock; Robert D. Lipschutz; Laura A. Miller; Kathy A. Stubblefield; Kevin B. Englehart. Targeted Muscle Reinnervation for Real-time Myoelectric Control of Multifunction Artificial Arms. JAMA, 2009;301(6):619-628 [link]

Cite This Page:

JAMA and Archives Journals. "New Surgical Technique Shows Promise For Improving Function Of Artificial Arms." ScienceDaily. ScienceDaily, 14 February 2009. <www.sciencedaily.com/releases/2009/02/090210161902.htm>.
JAMA and Archives Journals. (2009, February 14). New Surgical Technique Shows Promise For Improving Function Of Artificial Arms. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2009/02/090210161902.htm
JAMA and Archives Journals. "New Surgical Technique Shows Promise For Improving Function Of Artificial Arms." ScienceDaily. www.sciencedaily.com/releases/2009/02/090210161902.htm (accessed September 30, 2014).

Share This



More Health & Medicine News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How 'Yes Means Yes' Defines Sexual Assault

How 'Yes Means Yes' Defines Sexual Assault

Newsy (Sep. 29, 2014) Aimed at reducing sexual assaults on college campuses, California has adopted a new law changing the standard of consent for sexual activity. Video provided by Newsy
Powered by NewsLook.com
Scientists May Have Found An Early Sign Of Pancreatic Cancer

Scientists May Have Found An Early Sign Of Pancreatic Cancer

Newsy (Sep. 29, 2014) Researchers looked at 1,500 blood samples and determined people who developed pancreatic cancer had more branched chain amino acids. Video provided by Newsy
Powered by NewsLook.com
Colo. Doctors See Cluster of Enterovirus Cases

Colo. Doctors See Cluster of Enterovirus Cases

AP (Sep. 29, 2014) Doctors at the Children's Hospital of Colorado say they have treated over 4,000 children with serious respiratory illnesses since August. Nine of the patients have shown distinct neurological symptoms, including limb weakness. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Dr.'s Unsure of Cause of Fast-Spreading Virus

Dr.'s Unsure of Cause of Fast-Spreading Virus

AP (Sep. 29, 2014) Doctors at the Children's Hospital of Colorado say they have treated over 4,000 children with serious respiratory illnesses since August. Nine of the patients have shown distinct neurological symptoms, including limb weakness. (Sept. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins