Quantification of walking‐based physical activity and sedentary time in individuals with Rett syndrome

Abstract

AIM To quantify, in individuals with Rett syndrome with the capacity to walk, walking-based activity and sedentary time, and to analyse the influences of age, walking ability, scoliosis, and the severity of epilepsy. METHOD Sixty-four participants with a mean age of 17 years and 7 months (standard deviation [SD] 9y) were recruited from the Australian Rett Syndrome Database for this cross-sectional study. Each participant wore a StepWatch Activity Monitor for at least 4 days. Linear regression models were used to assess relationships between daily step count and the proportion of waking hours spent in sedentary time with the covariates of age group, walking ability, presence of scoliosis, and frequency of seizures. RESULTS On average, 62% (SD 19%) of waking hours were sedentary and 20% (SD 8%) was at cadences lower than or equal to 20 steps in a minute. The median daily steps count was 5093 (interquartile range 2026–8602). Compared with girls younger than 13 years of age and accounting for the effects of covariates, adults took fewer steps, and both teenagers and adults had more sedentary time. INTERPRETATION Teenagers and adults led the least active lives and would appear to be in particular need of interventions aiming to optimize slow walking-based physical activity and reduce sedentary time.

Motor function in Rett syndrome: comparing clinical and parental assessments

“…Large deletions and amino‐terminal mutations were associated with a more severe outcome, whereas carboxy‐terminal mutations were associated with relatively better performance, at least in standing, sitting, and walking. A similar protective effect of carboxy‐terminal mutations has previously been reported for hand function, but not for walking . ‘Other’ mutations have been described as favouring correct hand function, but in the present study they were associated with more severe impairment of (loco‐)motor function.…”

“…In the group of patients who were unable to walk, most common mutations were carboxy‐terminal deletions, early truncating, or p.Arg168*. There is also a correlation between the presence of scoliosis and walking impairment; in the study by Downs et al, scoliosis had been diagnosed in 86% of females who were unable to walk. Even when present, walking shows some peculiar patterns due to ataxia, lack of core stability, and lack of feed‐forward control of movement at gait initiation .…”

“…Motor impairment in RTT has a severe impact on child development and leads to restriction of activity and participation. A recent study conducted on the Australian Rett Syndrome Database showed that around 37% of patients were unable to walk and about 16% walked with assistance . In the group of patients who were unable to walk, most common mutations were carboxy‐terminal deletions, early truncating, or p.Arg168*.…”

Respiratory morbidity in Rett syndrome: an observational study

“…Exercise has multiple positive effects on respiratory function, including increased minute ventilation and cardiac output, and reduced ventilation and perfusion mismatch by recruitment of lung zones with low ventilation or low perfusion and mobilization of secretions for easier coughing . Individuals with Rett syndrome who need assistance to walk are sedentary for approximately three‐quarters of the day . These data suggest that replacing sedentary time by light physical activity with daily routines could exploit these mechanisms to improve respiratory health in Rett syndrome with greater effect.…”

A life course approach to increase physical activity in individuals with Rett syndrome

“…In the last decade we have seen a growing awareness and an exponential increase in research on physical activity and sedentary behaviour in individuals with a range of child‐onset disabilities. Downs et al are particularly interested in the possible impact of movement limitations combined with comorbidities in individuals with Rett syndrome . Their study provides a good understanding through objectively measured habitual physical activity.…”