Renowned neuromuscular disease authority Irwin Siegel wrote these words for an MDA publication targeted at children:

"Braces are like muscles, except they're outside, not inside, a kid's legs. With braces, many of these kids don't have to work as hard and don't get tired so easily. They're able to stand and walk and do lots of things."

For children and adults, the use of braces to provide external "muscle" can improve mobility and enhance quality of life.

There's no such thing as a typical brace for people with Duchenne muscular dystrophy (DMD), spinal muscular atrophy (SMA), Charcot-Marie-Tooth disease (CMT) or any of the other disorders covered by MDA. The particular muscle weakness, much more than the disease, is the key to brace selection.

"We address the problem, the weakness," says Danny Chan, an orthotist with Novacare in Tucson, Ariz., who fits braces for patients served by the MDA clinic at University of Arizona Medical Center. He also oversees the actual manufacture of the devices and conducts follow-up care.

Other key members of the decision-making team when it comes to brace selection are the physician, physical therapist and the patient. Braces must be chosen with care. A pair of braces that's too heavy -- or improperly fit -- or which immobilizes a joint that needs to remain flexible -- can increase disability rather than alleviate it.

AFOs

Bracing in the lower extremities for neuromuscular conditions is fairly common, with an AFO, or ankle-foot orthosis.

Orthotist Tom Coburn helps William Randall on with his ankle-foot orthosis at the MDA clinic at New England Medical Center Hospital in Boston. Randall has CMT.

Ankle-foot indicates the range of the area receiving support. An orthosis is any external device that supplies support to part of the body, while a prosthesis actually stands in for a body part.

Robert McMichael, director of the MDA clinic in Arlington, Texas, says there must be a learning period for patients who use AFOs. "I don't think that wearing AFOs is natural. It's something you've got to learn how to do."

Many kinds of AFOs are available, made of plastic or metal or a combination of both. Some AFOs are fixed at the ankle and some are designed to allow for a range of motion.

A problem that occurs in diseases such as CMT or amyotrophic lateral sclerosis (ALS) is "foot drop," which can literally cause a patient to trip over his own feet. An AFO, properly applied, can provide stability in the ankle and prevent foot drop, and allow a user to walk with less fear of falling.

In the old days, AFOs tended to be cumbersome affairs with heavy metal struts that needed to be anchored to a special pair of shoes. Nowadays, lightweight, moldable plastics are preferred for the main material of the brace.

The relative lightness of the newer brace is a plus. The bottom part of the lighter AFOs can be slipped inside a normal sneaker. Today's AFOs can be covered with socks or trousers, making the braces undetectable to all but the keenest eyes.

FATHER AND SON

Dennis Blum, 53, of Allentown, Pa., and his son Matt, 17, simultaneously received a diagnosis of CMT about four years ago. Both were fitted with AFOs. Matt's braces were hinged, but Dennis, who was having problems with foot drop, received a one-piece appliance that was fixed at the ankle.

Dennis' braces helped him to continue his work as a surveyor for a number of years, and Matt's help him pursue a passion for working with computers.

Dennis, who was instructed to wear light sneakers over his braces, regrets that because of the AFOs he can't wear dress shoes to church. He compromises by wearing black sneakers on Sundays.

The price for a pair of braces can range from hundreds of dollars to several thousand. Dennis' one-piece AFO cost about $1,400, while Matt's hinged AFO was considerably more expensive.

When leg braces are medically prescribed by an MDA clinic physician, MDA assists with purchase and repair.

BRACE MAKING 101

A molded, customized brace is made first by taking a cast of the area to be braced, such as the lower leg and foot, while making sure the extremity is held in the desired position.

After that, the cast is filled with plaster to form a three-dimensional model, which ends up looking something like a leg broken off a statue.

Then thermoplastic is placed around the model and forced to adhere to it using extreme heat and vacuum suction. Once it dries, excess material is trimmed away and you have a thermoplastic appliance that molds exactly to the patient's leg.

While plastic has its advantages, metal uprights are still used in many braces, especially in appliances that extend above the knee, such as KAFOs, knee-ankle-foot orthoses.

Chan says that for patients who experience swelling or irritation of the skin, metal struts are better than lightweight plastic braces. That's because the plastic appliances come in contact with a much greater area of skin with a greater potential for irritation.

The principle of follow-up care dictates that not just the wearer but the brace itself needs to be examined and re-evaluated on a regular basis. Bodily changes such as weight fluctuation, callus formation or growth spurts in children can cause a customized brace to stop fitting properly.

A device called a heat gun, which resembles a super-powered hair dryer, can be used to heat and reshape the appliance when necessary.

"Many people will make one or more trips back to the orthotist to have it remolded a little bit," McMichael says.

PROLONGING WALKING

In his book, Muscle and Its Disorders (1986, Year Book Medical Publishers Inc.), Siegel writes that the use of braces, usually in combination with a surgical procedure to ease contractures (tightening or shortening of tendons), can help boys with DMD extend their ability to walk by two to four years beyond the time they'd otherwise start using a wheelchair. (See "Fight Against Contractures," Quest, vol. 3, no. 4.)

It's possible for braces to be prescribed without surgery as a preventative against contractures before they've formed. Night splints are basically leg braces worn during sleep to maintain positioning that guards against forming of contractures.

However, once contractures of the heel cords, hips or knees have formed, the problem must be dealt with, usually via surgery. Unless the deformity caused by contractures is corrected, braces can't be fitted properly. Measurement for braces can be undertaken shortly after the surgery.

"We do the operative procedure and then have the molds taken for the bracing while the patient is still in the operating room asleep," says Edwards Schwentker, co-director of the MDA clinic at Hershey Medical Center in Pennsylvania. Fitting must be done quickly, before postoperative swelling sets in. Otherwise, it can be done days later after the swelling has gone down.

KAFOs are often used after surgery in DMD. They can incorporate sophisticated components at the joints; some have the capability to lock automatically at the knee once the leg is straightened.

A patient's success using braces can depend on a number of factors, including the level of motivation. Alan E.H. Emery, in Duchenne Muscular Dystrophy (1993, Oxford University Press), warns that obesity or mental impairment can be obstacles to success using braces, and timing of surgical intervention is critical.

Steven P. Ringel, in Neuromuscular Disorders (1987, Raven Press Books), notes that most children walk more slowly after bracing, and adds: "For those to whom walking is important and motivation is high, bracing and surgery are encouraged to allow walking to continue. However, in other situations, the added labor and frustration of bracing and surgery can be a burden to the family."

Schwentker says that a family's decision with regard to the question of prolonging walking through surgery and bracing is a personal one; whatever a family decides should be respected by the physician.

OTHER DEVICES

Occasionally, devices that extend higher than KAFOs, such as HKAFOs -- hip-knee-ankle-foot orthoses -- may be prescribed. However, they can be problematic in patients with decreasing strength, since the extra weight and the immobility they impose on joints may end up hindering more than helping.

In type II SMA, various bracing devices may help a child remain upright as much as possible, thus discouraging the onset of scoliosis (curvature of the spine). These devices may include standing frames, KAFOs and body braces.

With the help of AFOs, Shirley Webb gets the most out of her motorized standing wheelchair.

Victor Dubowitz, in Muscle Disorders in Childhood (1995, W.B. Saunders Company), advocates that SMA children try to use standing frames in the first several years of life. Then the family and physician can assess whether the child is strong enough for KAFOs.

Carol Stumpf, a physical therapist and manager of rehabilitation at University of Arizona Medical Center, recently recommended long leg braces for a little girl with SMA. "The hope is that she will be standing," Stumpf says. "I don't know that she'll be able to walk with them, but I hope she'll be able to stand." (See "Taking a Stand," Quest, vol. 5, no. 3.)

In some cases, the use of a body brace, sometimes called a body jacket, may be recommended to help prevent scoliosis. Matt Blum wore one until he completed a teen-age growth spurt, but now only requires periodic evaluation of his spine.

Shirley Webb of Surfside Beach, S.C., has been using AFOs for two years. They don't enable her to walk but they do allow her to use a motorized standing wheelchair. She enjoys the looks of admiration she receives zipping around the mall in her upright position, thanks to her braces and standing chair.

Another kind of appliance, a neck brace, may be prescribed for disorders such as ALS in which neck weakness causes the head to drop.

TEAM INTERACTION

Communication between the patient and the various professionals involved is crucial for successful fitting of braces.

"I like to discuss the various options with the patient," McMichael says. "And then, if the orthotist thinks a different option will be better, I usually listen to him. And then I like to send the patient back to the physical therapist for a bit of practice training once the braces are made."

A less costly alternative to a custom-made set of braces is the "off-the-shelf" kind stocked by medical supply outlets. "They're prefabricated and they're much less expensive," Schwentker says. "If the patient has some degree of deformity in the foot, they won't work."

"They're not as comfortable because everyone's leg is shaped differently," Stumpf says.

Use of an off-the-shelf AFO may be justifiable in rapidly progressing cases of ALS in which the patient may only need the appliance for a few months.

AFOs and other kinds of braces can last for many years, but eventually are subject to wear and breakage.

"Mine cracked after a year or two," recalls Dennis Blum, who says that his outdoor work in extreme temperatures as a surveyor might have contributed to the brace's early demise.

"The patient who's very active is going to be more likely to break it," McMichael says. "Those who get the most value from it are the ones who are most likely to need a new one."