Tag Archive: knee braces


Bracing for change

I haven’t posted in over a year…but I have a good excuse: I have been working on my dissertation. Soon (hopefully) I will be wrapping up my PhD at the University at Buffalo. If you are curious about the Biomechanics Lab where I do my research, check out these pictures: https://www.instagram.com/p/BlOKn_YgKTL/?utm_source=ig_web_copy_link

I just got back from SciComCon at Cornell University, a science communication conference for graduate students. It was a great experience and got me thinking about how important it is to tell people about research. Part of the conference included writing a piece about our particular area of expertise. I chose to write about the struggle to bring bracing into the modern era. I realized that I hadn’t really discussed this on my blog, so I am sharing it here.

(Warning: members of the orthotics and prosthetics community – you might not like this very much. For one thing, I didn’t use the term “orthoses”…I also criticize the L-code system and point out the lack of scholarly research. Tough words, but these are things that have to change in order to ensure that our field survives in the future. Feel free to comment on this post to start a dialogue).

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For hundreds of years, braces consisted of rigid metal bars and hinges held on to the body with leather straps or strips of cloth. They were made for each individual patient by craftsmen such as armorers, tinkers, blacksmiths and cobblers. The advancement of plastics in the mid 20th century led to cosmetic upgrades, but the metal components of braces remained largely unchanged. (Picture 1: antique leg brace, Picture 2: modern leg brace)

bracebent08

In the 1980s, brace makers formalized the profession and established a list of acceptable types of braces in order to ease the prescription and insurance process. Braces were fabricated to include the components described on the list, special emphasis was placed on the specific type of hinges that would be used in leg braces. This system was important to ensure standardized care for patients. The problem is, we are still using the same list. The field is stuck in a time warp, where only the types of braces that existed in the 1980’s are considered to be legitimate medical devices today.

In recent years, prefabricated braces have become widely available. Braces now come in sizes just like T-shirts, with handy velcro straps that allow for fine-tuned adjustments. Gone is the muss and fuss of making each individual brace from scratch, but bracing innovation continues to be limited by the constraints of the list from the 1980’s. Prefabricated braces have bars and hinges that have been reverse-engineered so that they meet the specifications of the list. However, these elements are removable, or made out of lightweight plastic so that the patient can have a comfortable brace which they are likely to actually wear. This is as ridiculous as an iphone being packaged with an optional rotary dial in order to be classified as a telephone. (Picture 3: a knee brace with removable hinges, Picture 4: a knee brace with very minimal hinges)

 

03k0401-hinges-for-medial-and-lateral-stability-in-obesity-knee-pain_800xdonjoy-reaction-knee-brace-gray

There is another troubling fact about braces: we are not exactly sure what they do. In the days of more primitive orthopedic treatment, braces were needed to mechanically support limbs that were weakened or twisted by trauma or disease. These days, braces are likely to be worn for more mild complaints, such as after a sprain or to cope with arthritis pain.

Those of us who provide braces operate on the theory that they help to improve alignment, reduce pathological movement, provide support, or prevent further injury. But, when we are asked for the evidence base of our practice, there is an alarmingly scant number of studies about the effects of braces. Bracing studies that do exist often have very small numbers of subjects or lack objectivity because they are sponsored by the brace manufacturers. Top quality studies, such as randomized control trials, are virtually non-existent.

After a few years of working in the bracing profession, I became frustrated with fulfilling the requirements of a list that had been established before I was born.  I was also bothered by uncertainties about the effectiveness of bracing. I no longer felt sure that my work was helping people. My patients claimed to feel better when they wore their new braces, but I wasn’t willing to take this anecdotal evidence as proof. I wasn’t satisfied, so I went back to grad school to do some research of my own.

I focused my research on measuring the effects of leg braces. To narrow the question even further, I picked the one component that all types of leg braces have in common – the straps. Straps were considered so basic that they were not even mentioned in the list from the 1980’s. But, straps are important, every brace has to be held on somehow. (Look back at all four of the braces pictured previously and notice that they all have a strap just below the knee. This is the area that I had my subjects wear the straps around their legs.) Modern brace straps are made out of padded velcro. I could imitate this in the biomechanics lab for a few dollars. Because I was committed to starting basic, I decided to look at the effects of wearing brace straps on standing – reasoning that you have to stand before you can walk.

My experiments showed that people were aware of a sense of compression around their muscles when wearing brace straps on their legs. The subjects in my studies showed improvement in their balance when wearing the straps. These results suggest that the sensation of wearing velcro straps around the leg contributes some form of sensory aid which improves neuromuscular control.

Other researchers have had similar findings, where subjects were helped with use of flexible types of leg braces. It appears that when it comes to bracing, sometimes less is more.  Minimalist braces may have an effect, without including the bars and hinges that were traditionally considered fundamental components of braces. This possibility was not considered in the early days of the bracing industry, so non-rigid braces were not categorized as medical devices. I think our definitions of what constitutes a brace should change – it is about time to seriously amend the brace list.

There is so much research left to be done, which makes this an exciting and challenging field. Opportunities abound for collaboration between biomechanists, engineers, practitioners, and patients. New technology that could be used to create better bracing is constantly developing. A backlog of wearable devices and robotic exoskeletons is waiting to join the mainstream bracing offerings, if we can find a way to eliminate the bottleneck of historic regulations.  The possibilities are endless – I am excited about the future, but in order to get there, we have to overcome the limitations of the past.

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Suspension

Lately I’ve been fitting a lot of knee braces. Something about the summer time seems to prompt people to jump off things, ride their bicycles too fast and rollerblade on uneven surfaces. When their stunts go awry, these people come to see me to get fit for a brace.

Knee braces come in all shapes and sizes. Here are some examples:

If the patient is going to have knee surgery (such as to repair some torn ligaments) they will be fit with a brace that looks something like this:

If they need continued support after surgery and rehabilitation they may be assigned a functional brace something along these lines:

If the injury is not bad enough to need surgery but the patient has general soreness and swelling they will probably be given this sort of brace.

I will write a more detailed post another time about the function of each type of knee brace, but right now I want to focus on something that they all have in common. In order for a knee brace to work, it has to stay in the right place. It is really hard to keep a knee brace in the proper position. This is a problem that I never encountered with foot orthotics. You see, foot orthotics stay in place because you stand on top of them. Not so with knee braces. Good old gravity works against even the best brace and tries to pull it down.

In the orthotics world we call the ability of a brace to stay in the right place suspension. This is why knee braces have so many straps.  We are trying to suspend the brace above the ground by anchoring it firmly against the leg.

Gravity is only half the problem however. Most people have conical legs. That is to say, the circumference of their thigh is greater than the circumference of their calf. Think of the shape of an upside-down traffic cone.

conical legs

Now think this through with me – Let’s say your leg is shaped like that. Even if you were to tighten the straps on your brace down really hard, what is to keep the whole thing from sliding south? Not much. In fact, there is only 1 thing that stops the brace from migrating down around your ankles. It is called the Gastrocnemius and is definitely in my top 10 list of the coolest muscles in the body.

gastroc

The Gastrocnemius forms a little “shelf” in the back of the calf where the leg is a little bit skinnier just below the knee. This is the place to win the fight against gravity. In order for a knee brace to be suspended effectively it has to grab onto the leg right here. If you look back at the three types of knee braces at the top of this blog, you can see that each model has a strap in this spot. That is no coincidence.

brace stapping

Many knee brace wearers don’t understand this fact. People often over-tighten the straps of their brace and then they just have a really uncomfortable knee brace that still feels like it is going to fall off. This leads to skin irritation and rubbing and general miserableness that causes people to abandon their braces. Knee braces are only effective if they are actually worn. And worn correctly I might add.

If you are a knee brace wearer, don’t let gravity get the better of you. Harness the power of your Gastrocnemius and keep that brace suspended.

Also, enjoy the last of this warm summer weather and try not to hurt yourself doing anything stupid.

Walk well!

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