Restoring Balance in CMT: How Ground Reaction AFOs Improve Stability

For many Charcot-Marie-Tooth (CMT) patients, balance issues go far beyond simple foot drop. The real challenge? Maintaining stability while standing still or walking, due to proprioceptive loss and muscle weakness. Traditional AFOs often fail to address this, leaving patients relying on compensatory strategies—holding onto walls, leaning against counters, or avoiding open spaces altogether. The solution? Ground reaction AFOs, which use advanced design principles to restore balance, improve static stability, and help CMT patients regain confidence in movement.

Who Named It CMT, Anyway?

CMT is the common name for Hereditary Motor Sensory Neuropathy, HMSN. CMT is named after the 3 physicians who first described the condition in 1886. Dr. Jean Martin Charcot and Pierre Marie of the world famous Salpêtrière Hospital in Paris and Howard Henry Tooth, the young Cambridge University graduate from London. This hereditary peripheral neuropathy can significantly affect balance. Often patients I’ve fit and trained with AFOs will say that restoring static balance, that ability to stand still in open space, is the most valuable benefit from wearing AFOs. 

Balance Testing In CMT Treatment

We use the Romberg balance test to evaluate CMT patients for functional static balance. Romberg testing is performed with and without AFOs to determine efficacy.   Clinically, we use vibratory tests and great toe position tests to assess proprioceptive loss.  

Balance is simple physics. The center of gravity (COG) must remain positioned over the base of support. That is true for floor lamps and humans. Humans are more complicated as we are multisegmented structures that require stabilization of our skeletal segments. Our boney skeleton is jointed and our muscles control our joints and thus our position in space. Our peripheral nerves are what activate our muscles and send sensory information to our spinal cord and brain.  The over 140 chromosomal mutations associated with CMT are mainly responsible for the maintenance of our peripheral nerves. Consequently, our peripheral nerves undergo progressing demyelination and/or axonopathy resulting in progressing weakness and loss of tactile and proprioceptive sensation.  We lose the power to control our position and the information that tells us where all our distal segments are in space. 

The Basics Of Balance

The 4 main requirements for balance are muscle strength to actively position our COG over our base, vision, vestibular function and proprioception. 

We need functional muscle strength to operate our righting reactions. Our righting reactions are akin to righting a ship at sea.  Our base consists of a heel lever and a toe lever which maintain our position in the sagittal plane. As our COG shifts slightly posteriorly we simply dorsiflex and our heel lever will enlist the ground reaction force to shift it forward again. This is just like our floor lamp. If you push it slightly backward, the base will use the ground reaction force to bring it’s COG forward again. Being multisegmented humans we can also shift our COG at many more proximal segments, the hip, pelvis, trunk, head and of course upper extremities. These secondary strategies are what we refer to as compensatory strategies to position our COG over our base. They are less desirable as they come at higher energy costs and can interfere with activities like not spilling a martini. 

Prioritizing Proprioception In CMT Treatment

CMT impairs 2 out of the 4 balance requirements, decreasing our functional strength and impairing our proprioception. Proprioception is our ability to know where a body part is in space and how it is moving relative to the rest of the body. Physiologically, our muscle spindle fibers detect the exact length of our muscle fibers and send that information via afferent fibers in our peripheral nerves to the spinal cord and eventually the sensory cortex. To put it simply, that’s where our body position is seen like a constantly changing jigsaw puzzle. 

As we lose proprioception we again look to use compensatory strategies. The most common is to walk to a destination and casually maintain contact with a stationary object. Examples are a finger on a wall, a hip against a counter, a knee against a coffee table. This last one, I’ll come back to.  I am amazed how little it can take. One CMT patient told me he would walk across his lawn to the sidewalk where all he had to do was subtly back into a bush and he could stand perfectly still and talk to neighbors for hours.  

How AFOs Help With Proprioception And Balance

AFOs can restore balance via ground reaction forces. The required criteria for the AFOs are they must have a rigid anterior shell with adequate dynamic resistance to provide functional heel and toe levers. The more advanced the neuropathy the stronger the resistance needs to be. Shifting your COG forward into the anterior shell is like shifting it into that coffee table I mentioned above. Patients do need to have preserved tactile sensation to the proximal tibia, below the proximal height of the anterior shell. As long as they can feel the “coffee table effect” from the ground reaction AFO, they can interpret where they are in space and thus compensate for proprioceptive loss distally.. Like a finger on the wall, the “coffee table effect” provided by the ground reaction AFO will provide the wearer with the ability to know where they are in space and static balance is restored. There is an element of skill involved in using ground reaction forces at the proximal tibia to compensate for proprioception. Practicing for a couple of weeks seems to be a reasonable expectation. 

Balance also needs functional heel and toe levers for righting reactions. Typically, muscle  weakness seems to coincide with proprioceptive loss. In the sequence of muscle loss, plantar flexor weakness is the last of the ankle muscle groups to weaken. Plantar flexor weakness is insidious and patients don’t necessarily notice functional loss as it is so gradual. Patients compensate for lack of a toe lever by maintaining their COG posteriorly. They appear to walk behind their feet and avoid shifting their weight line forward. This robs them of propulsion and even in static standing makes balancing on a shorter base of support more difficult. Providing a dynamic carbon AFO with higher resistance to deflection restores the length of the toe lever and with that restoring a longer base to balance on. This eliminates the need to shift the weight line posteriorly and restores power and propulsion. Romberg testing in dynamic carbon AFOs demonstrates efficacy but nothing is as satisfying as a patient reporting they are “solid as a rock” in their AFOS. 

Restoring Confidence With Dynamic Balance

Dynamic balance is the ability to look up and around while walking. CMT patients usually walk with a downward gaze and avoid looking up in open space. As the dynamic carbon ground reaction AFOs deflect and maintain support throughout the gait cycle, the coffee table effect provides position information while in motion. Patients successfully fit and trained are then able to look up at the sky and track a plane flight left to right. They can also walk forward and look left and then right. This is how we test for dynamic balance and the efficacy of our AFOs. The patient reporting with a smile, “I haven’t been able to do this for years” is the best result. 

To me, this is what Restoring Confidence is all about. It’s one of our core values at CMT Mobility Rescue, and it’s one of the main reasons why I love helping CMT patients.

In Conclusion

The right CMT balance solutions don’t just prevent falls—they restore freedom. Ground reaction AFOs compensate for proprioceptive loss, allowing patients to stand steady and walk confidently without relying on external support. If you’ve struggled with balance, posture, or stability, it’s time to explore advanced bracing solutions tailored for CMT. Reach out to the CMT Mobility Rescue team today to learn how proper AFO fitting and gait training can help you reclaim mobility and move through life with more ease.