To keep their balance while standing upright, children and adolescents with Charcot-Marie-Tooth (CMT) disease seem to adopt a more stiff posture and sway their bodies less than healthy individuals, researchers report.
Their findings were published in the study, “Characterizing postural oscillation in children and adolescents with hereditary sensorimotor neuropathy,” in the journal PLOS ONE.
Balance and postural control problems are a significant cause of disability affecting children with CMT. The type of posture difficulties faced by these children, however, has been little investigated.
Given that CMT symptoms, including balance issues, commonly appear during childhood, “there will be an increased propensity to comorbidities [coexisting conditions] that lead to a sedentary lifestyle after sprains, falls and fractures,” according to the researchers.
It is important to identify which types of postural deficits occur in children with CMT as a way to guide preventive measures and physical therapy interventions.
To this end, researchers aimed to identify which components of postural control were impaired in children and adolescents with CMT, using a method called stabilometry, a type of balance test that measures body sway while in a standing position.
The cross-sectional study analyzed stabilometric measurements of 53 children between the ages of 6 and 17, including 29 patients with CMT and 24 healthy individuals used as controls.
Body sway was measured by recording the displacement of each individual’s center of pressure while in a quiet, upright position over a force platform (stabilometry). The test was performed under four different conditions: on a regular surface with open and closed eyes and on a foam surface with open and closed eyes. At least two trials of 30 seconds each were done for each test condition.
Compared with healthy controls, several stabilometry parameters changed in children and adolescents with CMT as the complexity of tasks increased, including a higher confidence ellipse area (which indicates the body sway area) and a decreased frequency of body oscillations.
The low postural control of CMT children and adolescents was therefore associated with particular deficits, namely a greater and faster sway, but less frequent body movements, compared with controls.
On a foam surface, CMT patients showed a reduced number of body oscillations, suggesting the use of increased stiffness to deal with the demand of the task, the researchers said.
Moreover, in these patients, less forward-backward body movements were also observed, which potentially indicates poor management of the upright position by the ankle joint.
“Children with CMT choose to reduce the frequency of body oscillation to deal with their standing position, especially when the sensory references are restricted,” the researchers wrote.
“Since postural control is in stage of development in children, we tried to find cues about how CMT children manage the upright position, while dealing with the disadvantages that the disease imposes,” they wrote.
“Our results show that CMT have an increase in confidence ellipse area and CoP [center of pressure] velocity associated with the decrease of frequency in specific sensory/biomechanical conditions. There is need for more studies to expand this finding,” they conclude.