Abstract
Research Type:
Level 2 - Prospective comparative study, Meta-analysis of Level 2 studies or Level 1 studies with inconsistent results
Introduction/Purpose:
Charcot-Marie-Tooth (CMT) disease is the most common form of inherited peripheral neuropathy, affecting approximately 1 in 2,500 people in the United States. Progressive distal muscle weakness and imbalance often result in cavovarus foot deformity which contributes to poor gait mechanics, abnormal plantar pressure distributions, and an increased risk of falls – ultimately reducing quality of life. In CMT patients, abnormal plantar pressure patterns in the rearfoot and forefoot have been significantly linked to foot pain and associated with altered gait kinematics. The aim of this study was to evaluate regional dynamic plantar pressure patterns in CMT patients compared to healthy controls to identify regions of the foot that may be at high risk of injury.
Methods:
Twenty-five CMT patients (44.0±18.6 years, 15M/10F) with various genetic subtypes and eighteen healthy controls (44.5±17.3 years, 9M/9F) each completed three walking trials per foot across a plantar sensor platform (Novel EMED, Munich, Germany) [6]. The foot was divided into five regions based on foot length and the long plantar angle to evaluate loading throughout the stance phase of gait [7]. The rearfoot (31% of foot length), midfoot (19%), and forefoot (50%) were initially separated. Next the midfoot and forefoot were further divided into medial and lateral regions. Pressure-time integral (PTI) and peak pressure average and median values were recorded and compared using a Mann-Whitney U Test for both CMT patients and healthy controls, with the lateral-medial peak pressure ratio evaluated throughout the stance phase of gait.
Results:
Due to data non-uniformity, statistical significance was assessed using median values. Significant differences in PTI were observed between CMT patients and healthy controls in the rearfoot and lateral forefoot regions (Table 1). PTI was higher across all foot regions in CMT patients. Additionally, CMT patients exhibited a trend of increased peak pressures in the lateral foot regions compared to healthy controls. The largest absolute differences were observed in the lateral forefoot, followed by the lateral midfoot. Across the stance phase of gait, CMT patients had an increased ratio of lateral foot loading. Factors such as walking speed, BMI, or variability in CMT genetic subtype may contribute to increased PTI in CMT patients.
Conclusion:
Cavus foot and forefoot adduction increase the risk of fifth metatarsal fractures, particularly in zones two and three. Elevated lateral foot loading in CMT may heighten this risk, emphasizing the need to address structural abnormalities to prevent injury. Surgical intervention strategies aimed at restoring foot tripod positioning may effectively reduce pain and injury associated with lateral foot overloading. CMT studies evaluating foot deformity characteristics often have limited sample sizes. This study offers a comparable cohort to previous research, with the potential for substantial expansion to further investigate the plantar pressure differences between CMT patients and healthy controls.
