The Rocket Arm

As part of a $30 million federal program, a team of mechanical engineers at Vanderbilt University have successfully developed and tested a prosthetic arm powered by a miniature rocket motor.

"Our design does not have superhuman strength or capability, but it is closer in terms of function and power to a human arm than any previous prosthetic device that is self-powered and weighs about the same as a natural arm,” says Michael Goldfarb, the professor of mechanical engineering who is leading the effort.

The mechanical arm, which functions more naturally than previous ones, can curl about 20 to 25 pounds and do that three to four times faster than currently developed arms. The natural function occurs because, unlike current arms which only have an elbow and a claw, the prototype has an elbow joint and also has a wrist that twists and bends. And with a claw, the fingers and thumb have to move together but on the prototype they move independently.

The federal program, funded by a Defense Advanced Research Project Agency-DARPA- program, is also funding designs at the Advanced Physics Laboratory at John Hopkins University in Baltimore, MD, which uses batteries and electric motors, and at the University of Utah, the California Institute of Technology and the Rehabilitation Institute of Chicago, which in conjunction with batteries and electric motors, are developing arms that are controlled by connecting them to nerves in the users' bodies or brains. While battery power has been adequate for years, patients are wanting and needing to make more use of the arms which will consume much more energy. And increasing the size of the batteries to achieve more power will just become prohibitive because of weight. John Hopkins, the program leader for DARPA, was so impressed with Goldfarb's previous research into the miniaturization of a rocket motor system that is used by the space shuttle for maneuvering in orbit that they offered him $2.7 million in funding to apply it to the development of a prosthetic arm. And his power source is only the size of a pencil and contains a catalyst that causes hydrogen peroxide to burn which produces pure steam. This steam is used to open and close a series of valves which are connected to the spring loaded joints by belts. A small sealed canister of hydrogen peroxide that easily fits in the upper arm can provide enough energy to power the device for 18 hours of normal activity.

“There are only a handful of machinists who can make valves with this precision. We found one and asked him to make them with the highest precision possible, which is actually higher than he can measure,” says Goldfarb. “Normally in projects like this the surprises are unpleasant, but this was a pleasant one. The valves didn’t leak, click or hiss!”

"One of our immediate concerns was protecting the wearer and others in close proximity from the heat generated by the device. They covered the hottest part, the catalyst pack, with a millimeter-thick coating of a special insulating plastic that reduced the surface temperature enough so it was safe to touch. The hot steam exhaust was also a problem, which they decided to handle in as natural a fashion as possible: by venting it through a porous cover, where it condenses and turns into water droplets. The amount of water involved is about the same as a person would normally sweat from their arm in a warm day,” Goldfarb says.

Though it looks as if they might lose the DARPA funding because DARPA wants a commercially available arm in two years and the teams will need more time than that to make sure the technology is safe, they are confident that additional funding will become available due to the positive feedback they have gotten in the research community.

Modern Amputee Pitcher Dies at 87

Bert Shepard, 87, a World War II aviator who became an inspiration to the country when he recovered from the partial amputation of one leg and pitched for the Washington Nationals in 1945,died June 16 at a nursing home in Highland, Calif.

Washington's original American League baseball team was commonly known as the Senators but was officially named the Nationals through most of the 20th century. The team formally changed its name to the Senators in 1956.

A brother in Indiana said Shepard had been in relatively good health. The cause of death was not immediately apparent.

Shepard had been a minor-league baseball player before he was drafted into the Army in 1942. He signed up for flight training with the Army Air Forces and was shipped to England to pilot P-38 Lightning fighters.

During his 34th mission over Germany on May 21, 1944, Shepard's plane was hit by anti-aircraft fire. He later said he felt a sledgehammer-like blow to his right ankle. He lost consciousness when a bullet struck his chin. His airplane crashed at an estimated speed of 380 mph.

He was taken to a German hospital, where his right leg was amputated below the knee. Part of a bone over his right eye was removed as a result of striking the plane's controls.

After several months in prisoner of war camps, Shepard returned to the United States in February 1945 and was fitted for an artificial leg at Walter Reed Army Medical Center. When Secretary of War Robert Patterson asked what he wanted to do in life, Shepard said he wanted to play professional baseball. Patterson called Clark Griffith, owner of the Nationals, who arranged for a tryout.

"This is the thing I dreamed about in that prison camp for months - the day I could get back on a diamond," Shepard told The Washington Post.

As he tried to make the Nationals as a lefthanded pitcher and first baseman, he became an instant celebrity. "Seldom has any athlete received so much publicity in so short a time," Post sports columnist Walter Haight wrote.

He was named to the team's active roster in July 1945. Because many players were in the military, he was one of many unlikely players in the big leagues. On Aug. 4,1945, Shepard finally got his chance. In a game with the Boston Red Sox, the Nationals were trailing 14-2 in the third inning and Shepard was called in from the bullpen. He struck out the first batter he faced, George Metkovich, and pitched the rest of the game for the Nationals. In 5 1/3 innings, he allowed one run on three hits. He had two strikeouts, as the Nationals lost, 15-4.

It was Shepard's one moment of glory. The next season, the war was over, and Shepard failed to make the team.

A Sampling Of Prosthetic & Orthotic Terminologies


AAOP: American Academy of Orthotists and Prosthetists, A professional
society of ABC board certified practitioners. Founded 1970
ABC: American Board for Certification in Orthotics and Prosthetics, A certification board
for individuals and facilities providing orthotic and prosthetic services. Established 1948.
acquired amputation: limbs surgically removed due to disease or trauma.
adherent scar tissue: Tissue stuck down, usually to bone.
AE: Above elbow. Also referred to as transhumoral.
AFO: Ankle-Foot Orthosis; device that encompasses the lower leg and foot.
AK: Above knee. Also referred to as transfemoral.
amputation: the loss or absence of all or part of a limb.


BE: Below elbow. Also referred to as transradial.
bilateral: A double amputee. Both legs or both arms as in Bilateral BK etc.
BK: Below knee. Also referred to as transtibial.


CAPO: Canadian Association of Prosthetists and Orthotists.
Certification: A level of training that is verified by the appropriate professional organization.
It is your proof that the practitioner has the required TECHNICAL training. It in no way
certifies the personality or business practices of the practitioner or facility.
check or test socket: A temporary socket, often transparent, made over the plaster model to
aid in obtaining a proper fit. A successful test socket will then be remade into the definitive
(Codes) L-Codes: procedure codes for orthotics and prosthetics developed through the efforts
of HCFA (Health Care Financing Administration) and AOPA.
congenital amputee: Individual born missing a limb(s). Technically, these individuals are not
Amputees, but are considered to be "Limb Deficient.”
congenital anomaly: A birth abnormality such as a missing limb (amelia) or deformed limb
congenital defiency: condition present at birth, when all or part of a limb fails to develop
cosmesis: The outer, aesthetic covering of a prosthesis, usually made of foam or a rubber like
material. Foam cosmeses are almost always covered by a cosmetic stocking.


DAK: Double above knee (aka bilateral). Also referred to as Bilateral transfemoral.
definitive, or "permanent" prosthesis: A replacement for a missing limb or part of a limb
which meets accepted check-out standards for comfort, fit, alignment, function,
appearance, and durability.
disarticulation: An amputation through a joint: the hip, shoulder, knee, ankle, elbow, or
donning and doffing: The act of putting on and taking off a prosthesis.
dorsiflexion: Pointing the toe/foot upward, toward the body.


edema: swelling of the tissues.
endoskeletal prosthesis: One built more like a human skeleton with support and components
on the inside and a cosmetic cover on the outside.
energy storing foot: A prosthetic foot design that stores energy when weight is applied to it
and releases energy when the amputee transfers weight to the other foot.
eversion: To turn outward.
exoskeletal prosthesis: A prosthesis that is hollow on the inside with a hard outer surface to
bear weight.
extension assist: A method of assisting the prosthetic to "kick forward" on the swing through
phase to help speed up the walking cycle. Used primarily for seniors, high AK
amputations and those with limited strength in the residual limb.


HD: Hip disarticulation. Amputation which removes the leg at the hip joint, leaving the pelvis
HP Hemi-pelvectomy (HP): an amputation where approximately half of the pelvis is
HKAFO: Hip-Knee-Ankle-Foot Orthosis; device that encompasses the hip and leg.
heel strike: the moment when the heel makes contact with the floor at the end of the swing
through phase.


Immediate Post Operative Prosthesis: A temporary prosthesis applied in the operating room
immediately after the amputation.
inversion: To turn inward.
ischial containment socket: (SEE ischial tuberosity): The Ischial Containment socket cups the
Ischial bone on the inside and back as well as the bottom. By cupping, or containing this
bone inside the socket, the socket tends not to shift laterally (outside) when weight is put
on it, making walking more efficient.
ischial tuberosity: The bone that protrudes from the back of the pelvis (the "butt bone") that
may get sore when sitting on a hard surface for extended periods of time.


KAFO: Knee-Ankle-Foot Orthosis; device that encompasses the entire leg.
KD: Knee disarticulation. Amputation through the knee joint.
knee components: devices designed lo create a safe, smooth walking pattern.


lateral: To the side, away from the mid-line of the body.
liners: Used for suspension, comfort and protection of the residual limb.
LSO: Lumbosacral Orthosis; device that encompasses the lower torso .


manual locking: device that locks the knee in complete extension to prevent buckling and
medial: Toward the mid-line of the body.
modular prosthesis: An artificial limb assembled from components.
multiaxis foot: Allows inversion and eversion and rotation of the foot and is effective for
walking on uneven surfaces.
myoelectrics: Literally muscle electronics. Myoelectric prosthesis were first developed in
Russia. This is a technology used in upper-extremity prosthetics. The prosthesis contains
electrodes which are used to control the prosthesis via muscle contractions which in turn
control a motor in the terminal device, wrist rotator or elbow . An attached battery pack
provides the power system which translates the muscle contractions into movements of
the prosthesis.


neuroma: The end of a nerve left after amputation, which continues to grow in a cauliflower


occupational therapy/OT: evaluation and training to maximise independence and function in
daily living.
orthosis/brace: a plastic or metal device used to straighten and/or Support a body part,
improve function, or aid recovery.
orthotics: The profession of providing orthotic services.
orthotist: a patient-care practitioner who evaluates, designs, fabricates and fits orthoses
(braces) and other devices to straighten or support the body and/or the limbs.


partial foot amputation: An amputation on the front part of the foot; also called “Choppart
physical therapy/PT: the evaluation and treatment of disease, injury or disability through
the use of therapeutic exercises and modalities to strengthen muscles, improve range of
motion and decrease pain.
planarflexed/planar flexion: Means the toe is pointing down, toward the sole.
polycentric: multiple-axis joint.
prosthesis: An artificial part of the body.
prosthetics: The profession of providing cosmetic and/or functional restoration of missing
human parts.
prosthetist: A person involved in the science and art of prosthetics; one who designs and fits
artificial limbs.
posterior: The back side of the body.
pylon: A rigid member, usually tubular, between the socket or knee unit and the foot that
provides weight bearing support .


quad socket: The Quad socket has a shelf about one inch wide on the posterior wall of the
socket which the Ischial Tuberosity rests on . The Quad socket has four clearly defined


residual limb: The remaining portion of a limb after amputation, also called the “stump”.
RGO = Reciprocating Gait Orthosis; special HKAFO that allows paralyzed persons to walk
step over step; generally used with crutches for balance .


S.A.C.H.: Solid Ankle Cushioned Heel foot component. A very basic, “passive” foot; very
SD: Shoulder Disarticulation-- Amputation through the shoulder joint.
shrinker: A prosthetic reducer made of elastic material and designed to help control swelling
of the residual limb and/or shrink it in preparation for a prosthetic fitting.
single axis foot: Used since the Civil War, this foot has an ankle hinge that provides
dorsiflexion and planar flexion. i.e. , toe up & toe down.
single axis knee: free singing knee with small amount of friction.
socket: portion of prosthesis that fits around residual limb/stump and to which prosthetic
components are attached.
split hooks: terminal devices with two hook-shaped fingers operated through the action of
harness and cable systems.
stance control: friction device with an adjustable brake mechanism to add stability.
stance flexion: mimics normal knee flexion at heel strike.
stockinette: tubular open-ended cotton or nylon material.
stump: A word commonly used to refer to the residual limb. (SEE RESIDUAL LIMB)
stump sock: wool or cotton sock worn over residual limb to provide a cushion between the
skin and socket interface.
stump shrinker: an elastic wrap or compression sock worn on a residual limb to reduce
swelling and shape the limb.
suction: provides suspension by means of negative pressure vacuum in a socket; achieved by
forcing air out of the socket through a one-way valve when donning and using the
suspension system(s): The method used to hold the prosthesis on to the body. Includes
locking pin, TES belt, suspension sleeve, waist belt, and suction.
swing phase: prosthesis moving from full flexion to full extension .
Symes: A disarticulation amputation through the ankle joint that retains the fatty heel pad
portion for cushioning.


temporary prosthesis: A prosthesis made soon after an amputation as an inexpensive way to
help retrain a person to walk and balance while shrinking the residual limb.
TES belt: A neoprene or Lycra suspension system for AK prostheses that has a ring which
the prosthesis slides into. There is a neoprene belt that attaches around your waist by
velcro/hook and loop fastener.
TLSO: Thoracolumbar-Sacral Orthosis; device that encompasses the entire torso.
transtarsal amputation: Through the tarsal (tarsus) or foot bones. (SEE “PARTIAL FOOT


WHO: Wrist-Hand Orthosis; device that encompasses the wrist and hand.
wrist unit: component that allows interchanging or repositioning of terminal devices.

A Short History Of Prosthetics In Fiction

The earliest known writing about prosthetics is found in the sacred Hindu texts, the Vedas, wherein a warrior, Queen Vishpla, loses her leg in battle and has it replaced with an iron limb. That was written between 3500 and 1800 BC.
Ever since, the idea of humans becoming one with machine has fascinated us. As prosthetics technology continues to progress, so have our perceptions of it. At some points, they evoked thoughts of villainy, think Capt. Hook in "Peter Pan" or the unseen murderer in "The Fugitive", but artificial limbs are now worn by fictional characters who have become more sympathetic, often heroic. Here is a far-from-complete list of prosthetics in the fictional world:
Ahab : In Herman Melville's 1851 classic "Moby-Dick," the captain slowly paces the deck of the Pequod, his ivory leg thumping loudly with each step. The sound fills the entire crew with dread.
Steve Austin/Jaime Sommers : The "Six Million Dollar Man"which debuted in 1974, and "The Bionic Woman" two years later. Able to bend steel and run faster than 60 mph, the pair of government agents brought down doomsday machines and criminals alike. A reunion movie in 1989 also starred Sandra Bullock as a new generation of bionic crime fighter.
Luke Skywalker/Darth Vader : Besides the above bionic couple, Darth Vader is likely the most prosthetically enhanced of all fictional characters, having lost two legs, an arm and a hand in light-saber battles (most of which were lost when he was still the light-side-dwelling Anakin Skywalker). He would go on to lop off Luke's hand, which would be replaced by a fully functioning prosthesis.
Of course we should mention our cyborg friends, The Terminator, 1984, and it's sequels, with Arnold Schwarzenegger, and RoboCop, 1987, with Peter Weller (and RoboCop 2).
B.D. : The most realistic depiction listed here comes from Garry Trudeau's comic strip "Doonesbury." The arch-conservative foil took on a new dimension as a character when he lost a leg in the Iraq war in 2004. And after more than three decades, he finally took off his helmet.

Should There Have To Be A Mandate?

Beginning next year, health insurance policies written in Louisiana would have to provide at least $50,000 worth of coverage for those who need artificial limbs, under legislation approved 26-7 by the state Senate. There was little discussion about the bill on the Senate floor although some business and insurance interests had fought the measure earlier in the session, objecting to mandates that they said could drive up insurance costs.

The vote puts the bill close to final legislative passage. Already approved 69-32 in the House, it needs one more routine House vote on Senate language changes for final passage. Then it would go to Gov. Bobby Jindal, who would have to decide whether to sign or veto it.

And in Vermont, Gov. Jim Douglas recently signed into law a bill making Vermont the 10th state to require insurance companies to cover prosthetics as fully as they do other medical procedures. A similar measure is pending in Congress.

These laws say that if an insurance policy covers, say, 80 percent of the cost of any other medical procedure — whether a doctor's office visit or open-heart surgery — it must do the same for prosthetic limbs.

While many private insurers have strict limits on the devices, government programs tend to be more generous. Medicare, the government health insurance program for the elderly, covers 80 percent of prosthetic costs and, unlike many private insurers, does not consider the more expensive mechanical or computerized limbs to be experimental.

Opponents have cited information from the state insurance department that the requirement could cost insurers in the state more than $7 million a year. Backers of the bill by Rep. Charles Kleckley, R-Lake Charles, said those estimates were overblown and that such mandates in other states have ended up adding between 12 cents and 35 cents per month to insurance premiums.

Proponents, including Sen. Dale Erdey, R-Livingston, have repeatedly pointed to the case of would-be good Samaritan Carl Falconer, who lost both legs when he was hit by a car after stopping to help a woman change a flat tire. Erdey told the Senate that Falconer found out the prosthetics would cost him $40,000 apiece. "His health insurance would only pay $5,000 max," Erdey said

To Cover Or Not To Cover, It Should Be Your Choice

Whatever your opinion is of South African runner Oscar Pistorius' fight for a place on his country's Olympics team using two below-the-knee prosthetics that might give him an unfair advantage, it's hard not to be amazed watching him run. But it's not just the fact that he is running but the striking look of his artificial limbs — running blades made of carbon fiber where his feet once were. It's a futuristic look that gave him his nickname, Blade Runner, and for some amputees — mostly younger guys — that's a definite plus. Even though it is still common for top-notch prosthesis to look like an actual limb, these days with the stigma of being handicapped fading away and technologically getting better yearly, a new generation of prosthetics users are embracing a gleaming, mechanical look. Rather than trying to pass as able-bodied — as once was the norm for prosthesis users — choosing to present their disabilities to the world reflects a significant change in attitudes."It's a question of choice, and more and more people — especially young people — find it very cool to look like the Bionic Man," says Greenwich resident Paddy Rossbach, president and CEO of the Amputee Coalition of America. "People are finding themselves to be more active and feel good about themselves. Therefore, they are not trying to hide it. Some amputees now think it looks neat and walk around with shorts and are basically trying to show it off. They are saying, 'You know what — people know I lost a leg, so why try to hide it?'" It appears that many prosthetics users are embracing the Robocop look.

"They look at their prosthesis as a badge of honor by not covering it," says Meghan Eilbeck, marketing manager for Freedom Innovations, a maker of prosthetic limbs. "It's a show of what they've overcome, whether it's in athletics or not." For patients wanting a covered and detailed limb, work can involve duplicating the client's skin right down to the veins, hair and sunspots. It does cost for these extras and few insurance companies will cover costly cosmetic touches.

Some believe the war in Iraq might pressure insurance companies to provide better prosthetics coverage. At last count, about 780 soldiers have lost limbs in Iraq and Afghanistan. They account for only a small fraction of the 185,000 new amputees in the U.S. each year, but they're high-profile cases. If a 20-year-old soldier is outfitted with a state-of-the-art prosthetic, Robert Dzurenda of BioMetrics, a Trumbull provider of prostheses, says, it's hard for insurance companies to argue that a 20-year-old civilian couldn't also benefit from similar technology.

There are approximately 1.8 million Americans living without a limb. There are no figures for how many are using artificial limbs. Diabetes-related complications are the most common cause for amputations. And as the incidence of diabetes increases, due to the prevalence of obesity, so do the number of amputations , so the insurance companies are going to have to come to terms with what they are willing to pay for to make and keep their customers happy.