Slower, shorter steps found for Rett patients in 3D gait analysis

Findings may help clinicians decide on personalized treatment plans

Steve Bryson, PhD avatar

by Steve Bryson, PhD |

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Children, including one in a wheelchair, are shown together in a row, holding hands.

A comprehensive 3D gait analysis found patients with Rett syndrome, ages 5-18, had a slow walking speed and shorter step length relative to girls without the rare neurodevelopmental disorder.

The Rett patients also had wider step width and greater variability in gait features, as well as ataxia-like movements — seen as an unsteady, staggering gait — compared with the unaffected control individuals.

Objective gait assessments, as reported in this study, may help clinicians decide on personalized treatment plans for their patients and provide beneficial information to nonspecialists and parents, the researchers noted.

“Evaluating gait [problems due to Rett] while concentrating on subtle but important differences can lead to more suitable and tailored rehabilitation,” the team wrote.

The gait study, “Pathological gait in Rett syndrome: Quantitative evaluation using three-dimensional gait analysis,” was published in the European Journal of Paediatric Neurology.

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Rett patients found to have a slow walking speed compared with healthy girls

Gait problems are common among those with Rett syndrome, with about half of patients unable to walk independently by age 10. Those who can walk on their own typically move at a comparatively slow speed, and with a short step length. Ataxic-rigid gait, which can be described as an unsteady, staggering walking ability, is the most common gait characteristic in Rett.

Assessing walking ability in Rett patients can help healthcare specialists evaluate gait problems and provide measures that accurately reflect gait severity. Such measures also may be beneficial for nonspecialist pediatricians as well as parents or caregivers who have more interaction with these patients.

However, it can be challenging to fully assess movement abilities among Rett patients.

Three-dimensional gait analysis, dubbed 3DGA, is a method that accurately measures details of walking, running, and jumping in three dimensions. Although 3DGA has been investigated in some Rett studies, these were limited to treadmill walking and lacked proper controls as a comparison.

Now, investigators in Japan conducted a comprehensive gait analysis on 11 children and teens with Rett, with a median age of 9, who could walk independently. They used a 3DGA system that measured several gait parameters while walking on solid ground. The study included a group of 33 age-matched healthy girls as controls.

“To the best of our knowledge, this is the first study in which a comparative 3DGA was performed between patients with [Rett] and healthy controls,” the team wrote.

Among the patients, nine experienced epileptic seizures, and all were taking at least one antiseizure medication. Muscle tone abnormalities were reported in some participants, as well as ataxia and involuntary muscle contractions. Data also mentioned scoliosis, a sideways curvature of the spine, flat feet, and limited ankle movements in more than half of the patients.

In the 3DGA system, participants walked at their own speed barefoot for 2 meters (about 6 feet) across eight force plates placed flat on the ground. The participants wore reflective markers at various locations on their body, which allowed detailed recording of several gait parameters captured by eight cameras.

The results showed that the Rett patients walked significantly more slowly, with a decreased step length, a wider step, and a lower cadence (steps per minute) than controls.

Evaluating gait [problems due to Rett] while concentrating on subtle but important differences can lead to more suitable and tailored rehabilitation.

Overall, the Rett patients had significantly lower gait deviation index scores — a sign of impaired gait based on nine key movement measures of the pelvis, hip, knees, ankles, and feet. Significantly higher gait profile scores also were reported for those with Rett, and were an indicator of gait problems based on differences in multiple movement measures between patients and controls.

Researchers found greater differences between patients and controls in the sagittal or side-to-side plane in the pelvis, hip, knee, and ankle joint. Similar larger differences also were found in the coronal or front-to-back plane in the pelvis and hip joint, and the horizontal or top-to-bottom plane in the pelvis.

Rett patients exhibited limited extension of the hip joint, decreased range of motion in the knee joint, and excessive downward extension in the ankle joint. Excessive rotation in the foot angle and rotation in the pelvis, in addition to variations in many other measures, also were found in patients as compared with controls.

“Our results may help clinicians select suitable interventions for pathological gait in patients with [Rett], such as programs with a focus on coronal and horizontal abnormalities to improve gait abilities,” the researchers wrote.