Full length articleGait patterns of children and adolescents with Charcot-Marie-Tooth disease
Introduction
Charcot-Marie-Tooth disease (CMT) is a progressive genetic disease of the peripheral nervous system that affects approximately 1 in 2500 people [1]. More than 80 different genetic mutations have been identified causing CMT and is subcategorised based on features of demyelination or axonal loss and mode of inheritance. The onset and severity of symptoms varies between patients, even within the same CMT type. The most commonly characterised lower limb abnormalities are distal weakness resulting in foot drop, sensory loss, absent tendon reflexes, muscle cramps and cavovarus foot deformity [2], [3]. These signs and symptoms can result in many functional difficulties including ankle instability, tripping and falling, poor balance and foot pain all causing major problems with walking [3], [4]. There are no disease modifying therapies for CMT and clinical care focuses on managing symptoms with physical therapy, orthoses and orthopaedic surgery. Understanding the spectrum of gait abnormalities in children and adolescents with CMT will provide valuable information to guide treatment planning and monitor health outcomes.
The most common gait abnormalities for children and adults with CMT described in the literature include foot drop, reduced ankle power generation at push-off and increased knee and hip flexion or ‘steppage-gait’ as a compensation for swing clearance [5], [6], [7]. Several other primary deviations at the ankle and related compensatory mechanisms have also been reported, suggesting that people with CMT do not fit a single gait profile. Ounpuu et al. [8] divided 33 children with CMT (12 ± 4 years) into three groups based on peak ankle dorsiflexion in terminal stance: greater than typical, within typical and less than typical dorsiflexion range. The group with greater than typical peak dorsiflexion showed significant impairment of ankle plantarflexor and dorsiflexor strength whereas the group with less than typical dorsiflexion was the only group with plantarflexor contracture. Similarly, Ferrarin et al. [5] defined three gait patterns using cluster analysis in 21 children with CMT (11.9 ± 2.8 years), namely pseudo-normal, foot-drop only, and foot-drop with push-off deficit. However, none of these clusters described children with greater than typical peak ankle dorsiflexion as observed by Ounpuu and colleagues [8].
Various other compensatory mechanisms have also been reported. Ounpuu and colleagues identified pelvic hiking in swing and increased hip flexion as a compensation strategy for foot drop whereas the mechanism of increased external hip rotation was used to compensate for increased internal foot progression [8]. The only compensation mechanism consistent across all children was increased hip abduction which indicates a widened base of support to provide stability during walking. This increased hip abduction was also consistent with data collected on adults with CMT [6], [7]. In addition, Ferrarin et al. [5] reported early ankle plantarflexion in mid-stance (vaulting) as a compensatory mechanism used for contralateral foot clearance.
Only two studies have focussed entirely on children with CMT [5], [8]. Both have shown that children with CMT do not fit a single gait pattern, however these studies have reported inconsistent gait findings at the ankle in relatively small sample sizes (n = 21–33). Groups were also based on classifying patients according to their gait data. Instead, classifying patients based on their functional ability may result in the description of more meaningful clinical groups. Integrating both clinical measures with 3D gait analysis improves the interpretation of impairments related to walking difficulties and provides clinicians with crucial information to enhance treatment decisions. Identifying different gait patterns based on function will also be a valuable tool in clinical decision making, assessing disease progression and phenotype-genotype correlation studies to understand mutation-specific gait manifestations. The purpose of this study was to describe the 3D gait patterns of children and adolescents with CMT and distinguish differences based on the ability to heel and toe walk using the well-validated CMT Pediatric Scale [9].
Section snippets
Participants
Baseline data from 60 children with CMT (34 male, 26 female; mean age 11 ± 3.1yrs, mean height 147 ± 16.8 cm, mean weight 44 ± 17.4 kg), of various CMT types: 47 CMT1A, 1 CMT1E, 2 CMT1F, 1 CMT2A, 2 CMT4C, 4 CMTX1 and 3 CMTX3 who were involved in a 2-year randomised controlled trial of progressive resistance strength training (FAST study) were analysed [10]. Ethics approval was obtained from the Sydney Children’s Hospitals Network Human Research Ethics Committee (HREC/13/SCHN/21). Children were excluded
Children with CMT vs. healthy norms
Mean physical characteristics are shown in Table 2 and mean gait parameters for the CMTall group and healthy norms are shown in Table 3, Table 4. Compared to healthy norms, children with CMT had a significantly worse GPS. Primary deviations at the ankle showed significantly reduced ankle dorsiflexion in stance, reduced maximum ankle dorsiflexion during swing and at initial contact, reduced ankle dorsiflexor moment in loading response and reduced external thigh-foot angle in mid-stance (p <
Discussion
Compared to healthy norms, children with CMT exhibited significant gait abnormalities at the ankle including, reduced maximum ankle dorsiflexion in swing (foot drop) and reduced ankle dorsiflexor moment in loading response. The CMTall group also demonstrated a significantly reduced external thigh-foot angle in the transverse plane, indicating an altered foot alignment. No significant differences were observed in maximum ankle plantarflexion or ankle power generation at push-off.
In contrast to
Conclusion
This study provides further understanding of the relationship between functional ability in children with CMT and associated gait deviations. Not all children with CMT have the typically described foot drop, push-off deficit and ‘steppage gait’ pattern. Instead, three distinct gait patterns exist at the ankle: a group of children with CMT that have a near normal gait pattern, a group presenting with foot drop and a group with increased maximum dorsiflexion in stance and reduced push-off.
Conflict of interest statement
There are no conflicts of interest.
Acknowledgements
The authors would like to thank Anita Mudge and Leanne Purcell from the Paediatric Gait Analysis of New South Wales service for providing valuable assistance and support during data collection.
References (18)
- et al.
Factors that influence health-related quality of life in Australian adults with Charcot–Marie–Tooth disease
Neuromuscul. Disord.
(2008) - et al.
Gait pattern classification in children with Charcot-Marie-Tooth disease type 1A
Gait Posture
(2012) - et al.
The characteristics of gait in Charcot-Marie-Tooth disease types I and II
Gait Posture
(2007) - et al.
Foot drop and plantar flexion failure determine different gait strategies in Charcot-Marie-Tooth patients
Clin. Biomech. (Bristol, Avon)
(2007) - et al.
A comprehensive evaluation of the variation in ankle function during gait in children and youth with Charcot-Marie-Tooth disease
Gait Posture
(2013) - et al.
Randomised controlled trial protocol of foot and ankle exercise for children with Charcot-Marie-Tooth disease
J. Physiother.
(2014) - et al.
1000 Norms Project: protocol of a cross-sectional study cataloging human variation
Physiotherapy
(2016) Scaling gait data to body size
Gait Posture
(1996)- et al.
The gait profile score and movement analysis profile
Gait Posture
(2009)
Cited by (0)
- 1
FAST Study Group: University of Sydney: Joshua Burns, Amy D. Sman, Kayla M.D. Cornett, Elizabeth Wojciechowski, Manoj P. Menezes, Melissa R. Mandarakas, Kristy J. Rose, Paula Bray, Jennifer Baldwin, Marnee J. Mckay, Kathryn M. Refshauge, Jacqueline Raymond. Sydney Children’s Hospitals Network (Randwick and Westmead): Terri Walker, Hugo Sampaio, Anita Mudge, Leanne Purcell, Clare Miller, Kelly Gray, Meghan Harman, Natalie Gabrael and Robert A. Ouvrier. University of New South Wales: Michelle Farrar.