Overground or Treadmill Walking Suitable to Assess Gait in Rett Patients, Study Finds

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by Joana Carvalho |

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Walking overground or on a treadmill is suitable as a tool to observe and detect gait changes in people with Rett syndrome, a small study has found.

The study, “Characteristic behaviors associated with gait of individuals with Rett syndrome,” was published in the journal Disability and Rehabilitation and was led by scientists at the University of Houston.

Rett syndrome is characterized by developmental delays, including motor, social, and language impairments, which usually manifest at 6–18 months of age.

Early hypotonia, or low muscle tone, stereotypic (repetitive, purposeless) hand movements, ataxic gait, and postural difficulties are among the most common motor challenges.

These changes in gait can cause walking impairments, which in turn compromise patients’ quality of life. However, no robust, user-friendly instruments have become available that can be used by healthcare professionals or investigators to identify gait alterations in patients with Rett.


“An instrument that can be quickly and easily administered in a clinical setting and does not require either the patient’s or their caregivers’ input would be valuable to both clinicians and researchers,” the investigators wrote.

Here, they reported the findings of a study that aimed to document gait alterations in young girls with Rett while the girls walked overground or on a treadmill.

With this study, the investigators also intended to start developing a tool that could be used by physicians to identify the most prominent gait changes in Rett patients.

To that end, they recorded and analyzed videos of 14 girls (mean age of 9.2 years) with Rett who were still able to walk independently.

All girls completed an initial set of overground walking tests, in which they were asked to walk on a portable walkway (GAITRite). This was followed by several minutes of treadmill walking at an increasingly higher speed.

After watching the recordings, two researchers used a checklist to register the most important behaviors they had observed. In general, their opinions matched in 84.5% of the cases. When they disagreed, a third analyst was asked to watch the videos and decide which of the other two assessments was the most accurate.

Results showed that, apart from a few exceptions, the type and frequency of behaviors that the girls showed were identical while walking on the walkway and on the treadmill.

Freezing and veering (sudden change of direction) were the two most frequent behaviors. Specifically, overground walking led to freezing in 85.7% of the participants and to veering in 78.6%. In turn, the same percentage of girls (78.6%) showed freezing and veering in both overground and treadmill walking.

However, the amount of time girls stood still was shorter while walking on the treadmill than overground (maximum of 4.36 vs. 6.36 seconds). The percentage of girls who tip-toed while walking was also lower while on the treadmill than on the walkway (14.3% vs. 42.9%).

Ten of the girls either clapped or wringed their hands while walking in one of the testing modes. Four girls who clapped during overground walking also clapped during the treadmill test.

Regardless of the testing mode, nearly all the girls required external motivation to complete the tests, including verbal and physical encouragement cues.

“In general, participants behaved similarly during overground and treadmill walking,” the investigators concluded. “We conclude that both overground and treadmill walking are appropriate tools to evaluate gait in this population.”

Among the study’s limitations are the small number of participants and the inability to generalize the findings across different age ranges, the team said.