Office of Research & Development

VA research on

Prosthetics/Limb Loss


Introduction

In 1862, Congress appropriated $15,000 for the purchase of artificial limbs for soldiers and seamen disabled in the service of the United States, to be expended under the direction of the Surgeon General of the United States.

In 1866, the War Department (now the Department of Defense) was authorized to provide Union Veterans with transportation to and from their homes to a place where they could obtain their artificial limbs or devices, and to furnish those Veterans with new artificial limbs or devices every five years.

VA's involvement in providing prostheses to Veterans began in 1921, when the Veterans Bureau, a predecessor agency to the Department of Veterans Affairs, was give the responsibility to provide artificial limbs and appliances to World War I Veterans.

Today, VA's Prosthetics and Sensory Aids Service is the largest and most comprehensive provider of prosthetic devices and sensory aids in the world. Although the term "prosthetic device" may suggest images of artificial limbs, it actually refers to any device that supports or replaces a body part or function.

VA provides a full range of equipment and services to Veterans, ranging from items worn by the Veteran such as artificial limbs and hearing aids to those that improve accessibility, such as ramps and vehicle modifications, to devices surgically placed in the Veteran, such as hips and pacemakers.

The department has more than 70 locations at which orthotics and prosthetics are custom-fabricated and fitted, using state-of-the-art componentry. A list of VA orthotic and prosthetic providers can be found here. The American Board accredits each for Certification in Orthotics, Prosthetics and Pedorthics, the Board of Orthotic/Prosthetic Certification, or both.

top

Selected Major Accomplishments

  • 1947: Introduced the first mobility and orientation rehabilitation-training program for blinded Veterans
  • 2007: Unveiled the first powered ankle-foot prosthesis, as part of a team with researchers at MIT and Brown University
  • 2013: Reported on new technology to help restore the sense of touch for those who have lost an upper limb and use an artificial hand
  • 2014: Published results of a study on how users and clinicians feel about the DEKA arm, the first prosthetic arm capable of performing multiple simultaneous powered movements
  • 2015:
    • Invented a wheelchair allowing users to crank up the push rims to a standing position, providing them with increased functionality and independence
    • Began the first human study in the United States to investigate osseointegrated prosthetics, in which implants are firmly anchored in place by integrating implanted material in living bone
  • 2016: Determined that knee replacement surgery could benefit some patients aged 85 and older

top

New, Ongoing, and Published Research

To help meet the lifestyle and medical needs of Veterans who have lost limbs, VA researchers develop and test a wide variety of prosthetic devices. VA's goal is to offer Veterans prosthetics that will restore them to their highest possible level of functioning within their families, communities, and workplaces.

Some VA researchers are working on developing high-functioning artificial limbs that are very similar to their natural counterparts. Others are working on advanced wheelchair designs that promote mobility and independence for wheelchair users, and make it easier to use a wheelchair.

Still other VA researchers are using functional electrical stimulation and other technologies to help those with weak or paralyzed muscles, and developing and testing state-of-the-art adaptive devices to help those with vision or hearing loss.

top

➤ VA research centers

Many of the latest innovations and discoveries in prosthetics research in the United States take place at VA centers. These centers generally work in close partnership with affiliated universities, and sometimes with other institutions, as well as commercial partners and other federal agencies.

For example, VA's Advanced Platform Technology Center, in Cleveland, develops new technologies to help Veterans with motor and sensory problems and those who have lost limbs.

The Center for Functional Electrical Stimulation, also in Cleveland, uses controlled electrical current to make paralyzed muscles work again.

The Human Engineering Research Laboratories in Pittsburgh have made important contributions toward the design of wheelchairs, seating systems and other mobility systems.

And the Center of Excellence for Limb Loss Prevention and Prosthetic Engineering in Seattle focuses not only on helping those who have already undergone an amputation, but also on preventing limb loss in the first place, namely among those coping with complications from diabetes.

Finally, the VA Center of Excellence for Neurorestoration and Neurotechnology in Providence, R.I., supports research and development on brain-computer interfaces for people with paralysis or limb loss. Researchers there also evaluate new prosthetic limbs, and develop new ways to help people regain function in their limbs.

top

➤ Amputation and artificial limbs

The technology involved in creating artificial limbs has come a very long way since the Civil War. Today's VA researchers use leading-edge technologies such as robots and nanotechnology to create lighter limbs that integrate body, mind and machine to look, feel, and respond like real arms and legs. They are also studying ways to best match prosthetic components with amputees' needs, including those whose active lifestyles mean they need high-performance prosthetics.

Other researchers are looking at new ways to care for what remains of limbs after surgery, enabling wounds to heal far more quickly than ever before; developing programs to teach caregivers complementary and alternative techniques to lessen the anxiety and pain associated with limb loss; and evaluating CT scans of diabetic feet to identify the types of feet that are at the highest risk for ulcers and amputation.

Ankle-foot prosthesis—In 2007, a VA team working with researchers at MIT and Brown University introduced a "powered ankle-foot prosthesis," which uses tendon-like springs and an electric motor to move users forward. Studies have shown that patients using the powered ankle-foot expend less energy while walking, have better balance, and walk 15 percent faster. The device, now sold as the BiOM ankle, is now available for Veterans using VA care and active-duty service members.

Osseointegration study—Today, VA is sponsoring the first human study in the United States to investigate osseointegrated prosthetics. Osseointegration firmly anchors implants in place by integrating implanted material in living bone. The current study involves implanting specially designed and coated titanium implants into the femurs of amputees who have lost their knee and lower leg. The bone of the residual limb should grow into the implant, and their prosthetic can then be attached directly to the metal connector of the implant without the need for a socket.

After healing is complete, users should have better control of their prosthetic leg, and it should also be quicker and easier to put the leg on, and take it off. In late 2015 and early 2016, the first such device was implanted in two Veterans at the George E. Wahlen VA Medical Center in Salt Lake City.

In December 2015, a titanium implant was inserted into the patients' legs, and in February 2016, a docking mechanism extending from the implant through the skin was attached. Two more Veterans have been implanted since then, and the research team plans to implant six more patients in order to assess the feasibility and safety of the new implant in 10 patients over the next few years.

DEKA arm—In the area of upper-limb prosthetics, VA researchers and colleagues collected data on the DEKA advanced prosthetic arm over four years at four VA sites—New York, Tampa, Long Beach, California, and Providence, Rhode Island—and at the Center for the Intrepid, a military rehabilitation site in San Antonio, Texas. The study findings have been published in a number of journal articles, including two in 2014 in VA's Journal of Rehabilitation Research and Development.

The arm was developed by DEKA Integrated Solutions Corporation, based in Manchester, New Hampshire, with $40 million in funding from the Defense Advanced Research Projects Agency (DARPA), through its Revolutionizing Prosthetics Program. It is the first prosthetic arm capable of performing multiple simultaneous powered movements.

The U.S. Food and Drug Administration approved the DEKA Arm System in May 2014, paving the way for the device to be manufactured, marketed, and made available in the VA health system. The DEKA arm will also soon be available to the general public as the LUKE arm, manufactured by Mobius Bionics.

In a 2014 study led by researchers from the Providence VA Medical Center and Brown University, 24 upper-limb amputees were fitted with a second generation (Gen 2) DEKA arm, and 13 were fitted with a third-generation arm (Gen 3). After being trained on its use, they were surveyed about their experiences.

In all, 79 percent of Gen 2 and 85 percent of Gen 3 users indicated that they either wanted to receive, or might want to receive, a DEKA arm. In addition, 95 percent of Gen 2 users and 91 percent of Gen 3 users indicated that they were able to perform new activities they had been unable to perform with their existing prosthetic device.

top

➤ Blind rehabilitation

According to VA's Blind Rehabilitation Service, approximately 157,000 Veterans in the United States are now legally blind, and more than 1 million Veterans have low vision that causes a loss of ability to perform necessary daily activities.

Those figures are expected to increase in the years ahead as more Veterans from the Korean and Vietnam conflict eras develop vision loss from age-related diseases such as macular degeneration, diabetic retinopathy, and glaucoma.

In 1947, VA researchers introduced the first mobility and orientation rehabilitation training program for blind persons. Today, VA's Center for Visual and Neurocognition, based at the Atlanta VA Medical Center, has a number of projects to help blind people and those with low vision to find their way around independently with greater ease.

Smartphone app—Researchers at the center are developing a smartphone app that fuses data from the Global Positioning System with data from the magnetic compass, gyrocompass, and accelerometers found in most smartphones. The app will provide highly accurate location information that can help users easily find destinations such as a crosswalk or building entrance.

RFID tags—The center is also investigating the use of radio-frequency identification (RFID), the technology that allows people to scan items at a store or drive through a tollbooth with an E-ZPass tag. Researchers are looking at the possibility of placing RFID tags on Braille signs to send information automatically to smartphones that can read the tags. Currently, some Braille signs use low energy Bluetooth transmitters, but the batteries on those must be changed every few years, while RFID tags require no power.

HandSight—Center researchers are working on a Department of Defense-funded project called HandSight, in which a tiny camera small enough to embed in a false fingernail is worn by the user and connected to a smart watch. The watch vibrates to signal that the user has placed his or her finger on a line of text.

Scanning the finger along the text activates software that translates the text into spoken output heard on a Bluetooth earpiece. When the user touches an article of clothing, software in the watch recognizes the colors and patterns and helps with coordinating an ensemble.

top

➤ Using electrical signals to restore functioning

In 2009, VA estimated that about 42,000 Veterans have serious spinal cord injuries and disorders that may interfere with the brain signals that control muscle movement. Others have become blind from the loss of photoreceptors (cells which are responsible for detecting light and therefore enable us to see) in the eye.

For Veterans with these and some other types of functional loss, VA investigators hope to restore functioning with electrical currents delivered through a neural prosthesis. A neural prosthesis is an electrical or mechanical device that connects with the nervous system and supplements or replaces functions lost by diseases or injury.

Neural prosthesis studies—In 2006, VA researchers found that delivering small currents to electrodes implanted in weak or paralyzed leg muscles significantly enhanced walking ability in stroke patients. In a study described in a 2011 article, a research team consisting of VA, Brown University, Harvard University, and Massachusetts General Hospital researchers successfully implanted electrodes in the brains of volunteer research subjects whose arms and legs were paralyzed that allowed them to control robot arms with their thoughts. The electrodes continued to work 1,000 days after the sensors were implanted.

Conveying a sense of touch—Another research team in Cleveland has developed a new kind of implanted electrical nerve interface that can convey a sense of touch on a prosthetic hand. They learned in 2014 that the implants continued to work after 24 months, and as of this writing they continue to work.

Sensors in the prosthetic hand measure the pressure applied as the hand closes around or presses against something. These measurements are then recorded, converted into a specially coded electrical signals, and sent through wires to surgically implanted electrodes around nerve bundles in the forearm and upper arm.

When the electrical signal reaches the nerves, it is transmitted through healthy neural pathways not affected by the amputation to the brain. The brain interprets the sensation signals as if they had come from a normal hand.

These researchers have since been funded by DARPA to further advance the work.

Electrical stimulation and SCI—In 2015, researchers at VA's Cleveland FES Center and Case Western Reserve University completed a 10-year clinical trial to test a surgically implanted electrical stimulation system in people with spinal cord injuries (SCI). During the surgery, electrodes are implanted in muscles of the trunk and legs, and leads are connected to a stimulator.

By stimulating muscles, the system activates muscles to allow for standing, better balance, and exercise. Patients are given functional training and rehabilitation using the stimulation system, and are prescribed a course of exercise. Lab tests focus on strength, balance, and patients' abilities with or without the system.

In 2012, FES Center researchers published a study in which they tested 15 people with spinal cord injuries who had received such an implant to help them stand and exercise. The 15 patients were tested once they learned to use the device, and again a year later.

The researchers found that the patients had incorporated the neuroprostheses into their lives; that the system worked as well for patients after a year as it had when they first received it; and that the neuroprosthesis was safe and reliable to use.

top

➤ Knee replacement

Age and knee replacement—In 2016, researchers at the Iowa City VA Health System and the University of Iowa looked at whether knee replacement (total knee arthoplasty) is safe for Veterans aged 85 or older.

The researchers combined and analyzed data from 22 past studies to see if they could make a determination on the risks and benefits of the procedure for older patients.

They found that while the available evidence suggested slight increases in mortality and complications for older patients, several of the studies reported that both older and younger patients were highly satisfied after surgery, and were able to function better.

The team therefore concluded that age alone should not rule out such surgery.

New knee-replacement method—Another research team, at the Phoenix VA Health Care System, recently tested a new method of knee replacement called kinematic alignment. This method uses MRI scans and special software to create customized cutting guides used by the surgeon to prepare the bones surrounding the artificial knee, resulting in a more personalized fit.

In 2014, the team found that this method provided much better pain relief and was more effective in restoring function and range of movement than other knee replacement methods. Of the 58 Veterans who took part in the study, half received kinematically aligned knees. They were more than three times as likely to be pain-free two year after surgery and were able to walk 50 feet further, on average, in the hospital before discharge.

top

➤ Wheelchair technology

The Human Engineering Research Laboratories (HERL) in Pittsburgh, operated by VA and the University of Pittsburgh, have made important contributions toward the design of wheelchairs, seating systems and other mobility systems.

MEBot robotic wheelchair—Currently, the center is developing a robotic wheelchair called MEBot that can go up and down curbs and steps, and maintain a level seat over uneven terrain—giving Veterans who use wheelchairs for mobility unprecedented freedom and independence both outdoors and inside homes, shops, and offices.

The wheelchair has traction control, anti-skid braking and powered seat functions, including tilt, recline, leg-rest, and elevation. It has six wheels, an onboard computer and software, and an array of high-tech sensors and actuators. It is designed to navigate smoothly over gravelly or muddy roads, uneven slopes, wet grass, and other difficult terrain—and should allow users to avoid getting stuck on snow and ice.

The MEBot is now being tested at the center's lab, and may be commercially available within a few years.

Improved standing wheelchair—In 2015, a group at the Minneapolis VA Medical Center reported they had made improvements to the traditional standing wheelchair to help improve the ability of paralyzed Veterans to function. The researchers modified commercially available standing wheelchairs by adding a drive wheel that allows the push rim to rise so patients can reach it when they stand.

In existing models, patients who can't reach the push rim in the standing position are forced to sit before they can boost the chair and move themselves to a new location. The new chair, which is not yet available commercially, also keeps the chair's four wheels on the ground at all time, increasing both stability and maneuverability.

top

➤ BrainGate

VA has played a major role in supporting the development of BrainGate. The system, spearheaded by researchers at the Providence, Rhode Island, VA Medical Center and Brown University, relies on microelectrodes implanted in the brain to pick up neural signals.

The electrodes are placed in a part of the brain that controls voluntary movement. They send signals to an external decoder that translates them into commands for electronic or robotic devices.

The research team developing BrainGate hopes to create a technology that will restore movement, control and independence to people with paralysis or limb loss from conditions including ALS, brain stem stroke, and spinal cord injury.

BrainGate studies—A 2011 study, described above in the "neural prosthesis studies" subtopic of this page, found that the system continued to control a computer cursor accurately through brain activity more than 1,000 days after it was initially implanted.

In 2015, the BrainGate team reported the system could allow point-and-click communication by someone with incomplete locked-in syndrome, which can be caused by a spinal cord injury. In locked-in syndrome, patients are fully conscious but unable to move any muscles except for those that control eye movement.

They can see, hear, smell, taste, and even feel, but may be unable to speak or vocalize at all. Those with incomplete locked-in syndrome can make small movements of the head, fingers, and toes.

Another 2015 BrainGate study found that volunteers using the system were able to acquire "targets" on a computer screen, such as letters on a keyboard, more than twice as quickly as in previous studies, thanks to advances in the system.

The BrainGate team is now studying whether the system can be effective as a means of natural, intuitive control of prosthetic limbs, or as a way to help patients move their own paralyzed limbs. The latter work is being carried out in partnership with the Cleveland FES Center.

top

➤ ReWalk 'exoskeleton'

VA's Center of Excellence on the Medical Consequences of Spinal Cord Injury is located at the James J. Peters VA Medical Center in the Bronx, N.Y. The center's mission is to improve Veterans' quality of life and increase their longevity by preventing and intervening in the secondary medical consequences that result from having a spinal cord injury. These consequences can include bone and muscle loss, and metabolic and cardiovascular changes.

How ReWalk works—Researchers at the center continue to study an Israeli technology that allows paraplegics to stand, walk, and climb stairs, called ReWalk. ReWalk is a wearable robotic exoskeleton that provides powered hip and knee motion to enable individuals with SCI to stand upright, walk and turn. On their first day using the device, most people can stand and take a few steps, although it takes practice and training to use it properly.

Participants in past studies have lost fat tissue, their bowel function has improved, and their diabetes symptoms have been reduced. The center is now conducting further studies on ReWalk's impact on mobility, bowel function and cardio-metabolic health.

The researchers' work has provided critical data for the U.S. Food and Drug Administration, leading toward the agency's 2014 approval of ReWalk for sale in the United States. In 2015, VA announced it would provide the device to eligible Veterans who could benefit from it.

top

More on Our Website

top

Selected Scientific Articles by Our Researchers

A randomized controlled trial of functional neuromuscular stimulation in chronic stroke subjects. Daly JJ, Roenigk K, Holcomb J, Rogers JM, Butler K, Gansen J, McCabe J, Fredrikson E, Marsolais EB, Ruff RL. Stroke patients receiving functional neuromuscular stimulation have a significant advantage in improving gate components and knee flexion coordination after stroke. Stroke, 2006 Jan;37(1):172-8.

Neural control of cursor trajectory and click by a human with tetraplegia 1000 days after implant of an intracortical microelectrode array. Simeral JD, Kim SP, Black, MJ, Donoghue JP, Hochberg LR. A neural interface system based on an intracortical microelectrode array can provide repeatable, accurate point-and-click control of a computer interface to an individual with tetraplegia 1000 days after implantation of this sensor. J Neural Eng, 2011 Apr; 8(2):025027.

Bionic ankle-foot prosthesis normalizes walking gait for persons with leg amputation. Herr HM, Grabowski AM. Using a bionic ankle foot prostheses results in metabolic energy costs, preferred walking velocities, and biomechanical patterns not significantly different from people without an amputation. Proc Biol Sci. 2012 Feb 7;279(1728):457-64.

A randomized controlled trial of kinematically and mechanically aligned total knee replacements: two-year clinical results. Dossett HBG, Estrada NA, Swartz GJ, LeFevre GW, Kwasman BG. The use of a kinematic alignment technique performed with patient-specific guides provided better pain relief and restored better function and range of movement than the mechanical alignment technique performed with conventional instruments. Bone Joint J. 2014 Jul;96-B(7):907-13.

A neural interface provides long-term stable natural touch perception. Tan DW, Schiefer MA, Keith MW, Anderson JR, Tyler J, Tyler DJ. Implanted peripheral nerve interfaces in two human subjects with upper limb amputation provided stable, natural touch sensation in their hands for more than a year. Sci Transl Med. 2014 Oct 8;6(257):257ra138.

Do users want to receive a DEKA Arm and why? Overall findings from the Veterans Affairs Study to optimize the DEKA Arm. Resnik L., Latlief G., Klinger SL, Sasson N, Walters LS. The DEKA arm is a new upper-limb prosthetic enabling amputees to perform a wide range of tasks, which VA is testing for the Department of Defense. Most users either wanted to receive, or might want to receive, the new prosthetic. Prosthet Orthot Int, 2014 Dec:38(6):456-66.

Neural point-and-click communication by a person with incomplete locked-in syndrome. Bacher D, Jarosiewicz B, Masse NY, Stavisky SD, Simeral JD, Newell K, Oakley EM, Cash SS, Friehs G, Hochberg LR. This study demonstrates the first use of an intracortical brain-computer interface for neural point-and-click communication by an individual with incomplete locked-in syndrome. Neurorehabil Neural Repair. 2015 Jn;29(5):462-71.

Clinical translation of a high-performance neural prosthesis. Gilja V, Pandarinath C, Blabe CH, Nuyujukian P, Simeral JD, Sarma AA, Sorice BL, Perge JA, Jarosiewicz B, Hochberg LR, Shenoy KV, Henderson JM. Measured more than one year after implant, the BrainGate neural cursor-control system showed the highest published performance achieved by a person to date, more than double that of previous pilot clinical trial participants. Nat Med. 2015 Oct;21(10):1142-5.

Participatory design and validation of mobility enhancement robotic wheelchair. Daveler B, Salatin B, Gringle GG, Candiotti J, Wang H, Cooper RA. The overall design of a new mobility enhancement robotic wheelchair received positive feedback from electric powered wheelchair users. J Rehabil Res Dev. 2015;52(6):739-50.

Virtual typing by people with tetraplegia using a self-calibrating intracortical brain-computer interface. Jarosiewicz B, Sarma AA, Bacher D, Masse NY, Simeral JD, Sorice B, Oakley EM, Blabe C, Pandarinath C, Gilia V, Cash SS, Eskandar EN, Friehs B, Henderson JM, Shenoy KV, Donoghue JP, Hochberg LR. This study demonstrates that changes in neural activity can be corrected with software changes. Science Translational Medicine. 2015 Nov 11;7(313):313.

The effects of advanced age on primary total knee arthoplasty: a meta-analysis and systematic review. Kuperman EF, Schweizer M, Joy P, Gu X, Fang MM. Existing data supports offering total knee arthoplasty to select geriatric patients, although the risk of complications may be increased. BMC Geriatr. 2016 Feb 10;16:41.

top

Prosthetics Fact Sheet


Download PDF

VA Research in the News

VA and other U.S. Government Online Resources


Questions about the R&D website? Email the Web Team.

Any health information on this website is strictly for informational purposes and is not intended as medical advice. It should not be used to diagnose or treat any condition.