Are CMT Patients Under-Braced? A Look at AFOs & Gait Training

Too many Charcot-Marie-Tooth (CMT) patients are fitted with AFOs that only address foot drop while ignoring the bigger picture—balance, propulsion, and stability. The problem? Standard AFOs focus on swing phase corrections, but most mobility issues associated with CMT happen during stance phase. This is where proper bracing and training make all the difference.

Let me start by stating the obvious, no one wants to wear AFOs. AFOs are always somewhere below desirable on the comfort scale and occasionally cause skin damage. Loss of tactile sensation in the foot and lower leg certainly increases the risk of skin damage. Some AFOs require frequent adjustments which require appointments with your orthotist. AFOs always require larger and usually less fashionable shoes. Beyond that there are often insurance coverage issues. So, nothing very enticing yet.  

When given a choice all CMT wearers will opt for the least bulky and most comfortable designs. I have evaluated countless CMT patients with existing AFOs that do not address their weakness or balance issues as they are either unaware that there are more functional  designs or given the choice they just plain prefer the least bulky AFOs to wear. 

How CMT Works

CMT is a progressive inherited neuropathy. It is referred to as a length dependent peripheral neuropathy. The chromosomal mutations which are passed on to CMT patients code for proteins that metabolically provide maintenance of our peripheral nerves. As our peripheral nerves fall into disrepair, both axonal and demyelinating forms, we slowly lose muscle strength and sensation. The longest nerves are affected first, much like if all road maintenance in the country was halted, the longest roads would have more pot holes and fall into disrepair becoming less functional first. This fact makes the neuropathy somewhat predictable and we can expect a certain sequence of muscles to weaken. Dorsi flexors are usually among the first to weaken and foot drop is a consequence of this. That being the case, it is natural that patients are first provided AFOs which address foot drop. The result is, it works. However, this is a progressive neuropathy and AFOs should address the consequences of that progression. 

Foot Drop, A Primary Symptom For Those With CMT

Foot drop, foot drop, foot drop seems to be the main concern to be addressed by AFOs which is unfortunate because foot drop is proportionally a small issue for the CMT population. So many health care providers are focused on this one aspect. If foot drop is addressed then, “Bam”, our work is done here.

The reality is that foot drop is a swing phase event occuring only when the foot is swinging through the air. Most all types of AFOs are designed to preventing the resulting toe drag and tripping. The swing phase of gait makes up only 40% of the gait cycle.  It is during the stance phase of gait where most of the action is. Foot slap, lateral ankle instability, heel rise, balance, walking speed, and confidence take place in the stance phase.  These issues require more than an AFO designed for foot drop eg, PLS, spring assist designs, more flexible carbon designs with a posterior calf cuff, elastic shoe straps with ankle wraps etc. 

Why So Many With CMT Are Under-Braced 

CMT wearers who are under braced have to deal with the stance phase events. Wearers will compensate with a slower guarded gait pattern and a downward gaze to avoid falls. Despite wearing AFOs, they find they still need to limit their activities.  If they have functional plantar flexor weakness they cannot walk on their toes or cannot walk on their toes for more than a few steps.  This results in markedly decreased propulsion, or walking power. The symptom associated with it is early fatigue. All compensatory gait deviations require more energy expenditure but this one event, heel rise, is the largest single contributor to propulsion. Beyond that it affects our ability to stand with our weight line centered over our feet. Without the ability to plantar flex down on our fore foot CMT patients are forced to shift our center of gravity posteriorly shortening the length of our base of support. Walking up inclines and stairs requires us to be able to raise our entire body up against gravity. This is what functional plantar flexion strength provides. Without this ability these tasks become very inefficient, requiring compensation. Often pulling the body up the distance with a railing or assist from a companion. 

CMT patients far too often are compromising their walking and static balance with AFOs designed to address just foot drop. A small percentage of wearers, despite progression of symptoms, are just used to the way they walk with their existing AFOs. In truth those gait compensations are hard won as patients learn to compensate for progressing weakness and poor balance. A dramatic clinical improvement can seem excessively unnatural to some and despite increased power, speed and improved balance will still prefer their simple foot drop AFOs.  So yeah, in my 30 years of evaluating, fitting and gait training CMT patients, I find that many are underbraced. 

I have not discussed the anatomical mal-alignments which are characteristic of CMT. The specific sequence of muscle loss results in agonist/antagonist imbalances which subsequently create classic claw toes, anterior cavus feet with plantar flexed first rays, forefoot adduction and hindfoot equinovarus. These result in altering the weight line during the gait cycle and are all foundational to orthotic management. The truth is AFO design becomes exponentially more complicated with deformity. If the weight line can be corrected with aggressive posting then dynamic carbon designs are appropriate. Otherwise surgical consults are indicated to correct the weight line. If surgery is not an option then more creative custom AFOs are the next best option.  

Dynamic Carbon AFOs 

The most functional return will come from dynamic carbon ground reaction AFOs which will have an anterior shell. This design will restore the most function lost to CMT. If CMT had a mission statement, it would be to slowly weaken the leg muscles that control the feet and ankles, continuing until they all are non-functional. CMT also intends to slowly rob you of sensation below the knee including proprioception, which is our ability to know where a body part is in space and how it is moving relative to the rest of the body. This AFO design will restore the basic elements of gait which are; toe clearance in swing phase and all 4 stance phase rockers. It also provides strong ground reaction forces to compensate for proprioceptive loss which is a major component to static balance. Once all those basic elements are restored, it requires gait training to provide the wearer with the experience to walk normally again. Just providing the AFO is akin to giving someone a flying car. Without training, they will just drive around like they always have and flying it will remain a mystery. 

In Conclusion – Re-assess your AFOs regularly.

As the neuropathy progresses the most appropriate AFOs for Charcot-Marie-Tooth shouldn’t just prevent foot drop and toe drag—they should restore full mobility by addressing stance phase mechanics, balance, and propulsion. But AFOs alone aren’t enough—gait training is essential to unlocking their full potential.