Brace modification improves aerobic performance in Charcot-Marie-Tooth disease: a single-subject design

Area of Science:

• Neurology
• Biomedical Engineering
• Exercise Physiology

Background:

• Ankle-foot orthoses (AFOs) are used to manage lower motor neuron injuries, but evidence for their efficacy in progressive neuropathies like Charcot-Marie-Tooth disease is limited.
• Existing literature suggests AFOs can reduce energy expenditure in hemiplegic patients, yet specific physiologic data for lower motor neuron conditions are insufficient.
• This study investigated the impact of optimized AFOs on aerobic performance and perceived exertion in an individual with Charcot-Marie-Tooth disease.

Observation:

• A single-subject, A-B-A design study was conducted on a patient with Charcot-Marie-Tooth disease.
• The study utilized treadmill exercise tolerance testing with indirect calorimetry to measure oxygen consumption (VO2) and the Borg scale for perceived exertion.
• Comparisons were made between the patient's existing AFOs (A) and newly prescribed, optimized AFOs (B).

Findings:

• Optimized AFOs significantly reduced oxygen consumption (VO2), rate-pressure product, and perceived exertion at submaximal exercise intensities.
• The patient demonstrated a 20% increase in treadmill exercise test duration with the modified AFOs.
• Maximal aerobic capacity (Maximal VO2) remained unaffected by the AFO modifications.

Implications:

• Optimizing ankle-foot orthoses (AFOs) can enhance physiological performance and reduce perceived exertion during submaximal activities in patients with Charcot-Marie-Tooth disease.
• These findings suggest potential benefits of tailored AFO prescriptions for individuals with progressive neuropathies and other lower motor neuron injuries.
• Further large-scale, controlled trials are warranted to validate these benefits across broader patient populations with lower motor neuron conditions.