Gait and balance improvements with a carbon fiber ankle-foot orthosis in a patient with Charcot–Marie–Tooth disease: A case report

INTRODUCTION

Charcot–Marie–Tooth (CMT) disease is a group of inherited neurological disorders affecting the peripheral nerves, characterized by progressive muscle weakness, distal sensory loss, and foot deformities such as pes cavus and hammer toes, typically beginning in adolescence or early adulthood [Figure 1].^[1,2] CMT disease typically presents a distal-to-proximal progression of muscular weakness. Early in the disease, the intrinsic foot muscles, which are essential for arch support and fine motor control, are preferentially affected.^[1,2] As the condition advances, ankle dorsiflexors, particularly the tibialis anterior, weaken significantly, contributing to foot drop and gait disturbances.^[1-3] In later stages, plantar flexor muscles also become compromised, further reducing ankle stability and functional mobility. Systematic review studies have identified existing gaps in the epidemiological understanding of CMT across diverse ethnic groups worldwide.^[3]

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Figure 1:

Marked muscle atrophy with bilateral pes cavus and hammer toe deformities. (a) Superior view and (b) lateral view.

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One of the characteristic clinical features observed in patients with CMT disease is the “inverted champagne bottle” appearance of the lower limbs [Figure 1]. This presentation is indicative of the progressive nature of distal motor neuropathy associated with CMT. It is commonly used as a visual marker in both clinical assessment and disease progression monitoring. While no cure exists, long-term follow-up is essential in managing individuals with CMT disease due to its progressive nature.^[4,5] Physical therapists play a pivotal role by addressing gait abnormalities, foot drop, and poor dynamic balance through targeted therapeutic exercises, gait training, and orthotic recommendations.^[5,6]

Despite the relatively high prevalence of CMT, the role of physical therapy in managing functional impairments, particularly gait disturbances and foot drop, remains insufficiently represented in the literature. The primary objective of this case report is to address that gap by documenting the functional status and rehabilitation approach for a middle-aged patient with longstanding CMT. Presenting this case contributes to the growing need for clinical evidence that supports interdisciplinary management strategies aimed at improving mobility and quality of life in patients with progressive neuromuscular disorders.^[7]

CASE REPORT

A 42-year-old male patient presented to the physical therapy clinic with complaints of progressive unsteadiness and pronounced fatigue that significantly limited his ability to perform activities of daily living. Over the past 2 months, the patient had experienced multiple episodes of tripping and falling. Informed consent was obtained from the patient for sharing the clinical information presented in this case report. The patient was diagnosed with CMT1A disease at the age of 15 years. He maintains regular follow-up at the genetic clinic of a university hospital. Despite a surgical recommendation from an orthopedic surgeon, the patient remains doubtful about the benefits. He has received intermittent physical therapy focused on symptom relief, with limited access to specialized care due to the complexity of his condition. The patient reported that he is currently facing many challenges, mainly fatigue and exhaustion, especially after many hours at work, either teaching at the college or supervising students at the laboratory, in addition to long hours of research work. The patient complains of unsteady gait and poor balance. The researcher conducted a comprehensive evaluation using the total assessment-reassessment and evaluation using the biokinesiology approach.^[8] The total survey of patient medical history covered the chief complaint and history of present illness, past medical history, family history, and social history. The researcher collected all related information, including medications, imaging reports, laboratory work, comorbidities, and previous surgeries. Patient assessment revealed that he was unable to safely perform the 5-time squat-to-stand or assume single-leg standing on either side without support [Figure 2]. The patient managed to do five sit-to-stands. The patient was unable to perform ankle dorsiflexion actively but was able to achieve plantarflexion while seated in a standard chair [Figure 3]. From a standing position, the patient was unable to rise onto his tiptoes independently; however, with support from stall bars, he successfully performed tiptoe standing [Figure 3]. Within the session, reassessment revealed observable improvement in gait pattern when the patient used a regular cane. The physical therapy evaluation revealed distal sensory deficits in a stocking-like distribution. Manual muscle testing revealed significant weakness in the distal musculature, particularly the bilateral ankle dorsiflexors, which contributed to observable foot drop. Plantar flexor strength was moderately preserved, corresponding to a grade of 4 out of 5 on the Medical Research Council scale, a standardized tool widely utilized in clinical practice to assess voluntary muscle strength. In the proximal lower limb muscles, hip flexors and extensors were graded at 4/5, indicating relative sparing. Muscle atrophy was visibly pronounced in the distal lower extremities, presenting as a “stork leg” appearance [Figure 1]. These findings indicate impaired balance, altered gait mechanics, and an increased risk of falls.

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Figure 2:

Marked muscle weakness. (a) Inability to balance on the left leg, (b) Inability to balance on the right leg.

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Figure 3:

Marked muscle weakness. (a) Inability to dorsiflex and (b) preserved ability to plantarflex both ankles while seated. (c) Inability to dorsiflex and (d) preserved ability to plantarflex both ankles while standing and holding on stall bars.

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The patient demonstrated independent ambulation with fair to normal dynamic balance and a moderately impaired gait pattern. On using a standard cane, dynamic balance improved to a good or normal level. Furthermore, a marked improvement in gait quality and dynamic balance was observed when the patient wore the ankle-foot orthoses (AFOs), resulting in good+/normal dynamic balance [Figure 4]. Carbon fiber AFOs, incorporating an anterior shell and tibial guard, are typically designed to facilitate foot clearance during the swing phase and provide stability during the stance phase. However, in this patient, slight dorsiflexion (e.g., 2–5°) was incorporated for optimizing gait and alignment [Figure 5]. The therapist observed noticeable wear on the patient’s footwear and recommended replacing it with a well-cushioned, snug-fitting sneaker that accommodates the carbon fiber AFO comfortably. Proper footwear plays a crucial role in optimizing the effectiveness of the orthosis, enhancing stability, and improving gait mechanics, particularly in individuals with neuromuscular conditions [Figures 4 and 6]. The patient was seen twice per week and was instructed to wear the carbon fiber AFOs consistently, particularly during outdoor ambulation, to maximize functional benefits and ensure gait stability. Follow-up visits indicated patient consistent adherence to the use of the carbon fiber ankle-foot orthosis AFOs and cane. Observational gait analysis, conducted by an independent physical therapist, confirmed notable improvements in the patient’s gait pattern.

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Figure 4:

Marked muscle weakness. (a) Inability to achieve heel strike with the right foot and (b) successful left heel strike during level-surface walking while wearing an ankle-foot orthosis on the left leg.

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Figure 5:

Marked muscle weakness. (a) Inability to dorsiflex and (b) Restored dorsiflexion of both ankles while donning ankle-foot orthoses in a seated position on a standard chair.

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Figure 6:

Marked muscle weakness. (a) Left heel strike and (b) Right heel strike during level-surface walking while wearing ankle-foot orthoses.

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DISCUSSION

The complexity of diagnosing CMT disease often delays access to appropriate medical care. In this case, the patient’s progressive unsteadiness, fatigue, and distal muscle atrophy conform to the clinical profile of CMT. Given its slow progression and lack of curative treatment, rehabilitation interventions, particularly physical therapy, remain essential in maintaining function, addressing gait impairments, and minimizing fall risk over time.^[2,4,5]

In this case, the clinical presentation was characterized by foot deformities such as pes cavus, hammertoes, distal muscle wasting, compromised balance, and altered gait patterns. An interdisciplinary approach, including physical therapy and orthotic intervention, played a central role in maintaining functional mobility and optimizing quality of life.^[7] Early detection and personalized rehabilitation strategies were crucial for minimizing disability and promoting functional independence.^[2,4] Coordinated training was systematically implemented utilizing stall bars to provide graded levels of support, enabling patients to perform exercises with progressively increasing difficulty. Stall bars aid in developing foundational components such as stability and alignment, which are essential prerequisites for effective gait training.^[2]

In the present case, the use of full-length carbon fiber AFOs yielded marked improvements in balance, postural stability, and gait efficiency.^[6] Biomechanically, the customized carbon fiber AFOs provided dorsiflexion assistance during the swing phase and controlled ankle motion during stance, resulting in a more energy-efficient gait cycle. In addition, their slim profile and compatibility with most footwear improve patient compliance and functional integration into daily activities. It is worn on both legs, extending from below the knee down to the foot, providing support and stability to the ankle.^[4,9] The findings of a systematic review further emphasize the importance of tailoring assistive devices to meet the individual needs of patients with CMT disease.^[9]

An energy-efficient gait cycle is essential for individuals with CMT disease, as it reduces fatigue, enhances mobility, and supports sustained functional independence.^[10] Patients walked faster, with increased stride length and frequency, when braced with the AFOs.^[6] The AFOs served as biomechanical enhancers, enabling a more energy-efficient gait cycle. Kim et al. emphasized the necessity to tailor the orthoses based on the degree of impairment and the individualized functional needs of the patient.^[9] The inherent elasticity and lightweight properties of carbon fiber allow for energy storage and return during ambulation, thereby reducing compensatory movements such as hip hiking and circumduction. This case supports the value of integrating assistive technologies, such as canes and carbon fiber AFOs, in rehabilitation. While carbon fiber AFOs offer meaningful functional improvements, their high cost, limited post-fabrication adjustability, and reduced durability may constrain their accessibility and long-term clinical utility.

The patient initially expressed reluctance to use a cane, perceiving it as a symbol of aging or disability. The physical therapist employed a supportive and empathetic communication strategy. By emphasizing the functional benefits and selecting an ergonomically designed cane with an attractive aesthetic appearance, the therapist successfully helped the patient overcome the perceived stigma of using a cane at his current age. Real-life examples and peer experiences were shared to normalize the use of mobility aids across age groups. The collaborative and individualized nature of this intervention highlights the importance of addressing both the physical and psychosocial dimensions of rehabilitation. The findings of this study are limited by its single-case design; therefore, further research involving larger cohorts is recommended to improve the generalizability of the results.

CONCLUSION

Early diagnosis of CMT is essential for timely intervention to slow functional decline and enhance quality of life. Given its progressive nature, CMT requires a multidisciplinary approach. Utilizing appropriate assistive technologies, such as carbon fiber AFOs and mobility aids, plays a vital role in enhancing gait mechanics. These interventions not only enhance functional independence and safety but also contribute significantly to reducing fatigue and exhaustion. This coordinated care ensures individualized, responsive treatment that supports long-term independence and well-being. Future studies should explore long-term effectiveness, cost-efficiency, and user satisfaction, while also addressing material limitations and adaptability for broader clinical use.