CLINICAL BOTTOM LINE
“How could I apply this information?”
This article provides reference values on the distance walked during the 6-Minute Walk Test (6MWT) in children who are healthy aged 7 to 11 years living in the United States. The authors report that the 6MWT is a “reliable and valid measure of submaximal exercise capacity in children who are healthy” (p32). They report that the 6MWT may be a useful screening test to identify functional exercise capacity in children, examine change over time, and evaluate outcomes of interventions that emphasize improving functional mobility.
The authors suggest that 6MWT reference values, child anthropometrics (height, weight, body mass index [BMI]), and demographics (age, sex) are important when evaluating 6MWT outcomes in clinical populations. These reference values provide comparisons for therapists to evaluate their patients’ submaximal aerobic capacities against values from children with typical development living in the United States.
“What should I be mindful about in applying this information?”
Therapists should be mindful that “normative” data serve primarily as a “comparison” to determine how different their patients are from the “healthy population” on distance traveled during the 6MWT. The authors indicate that it is important to make “specific” comparisons on child characteristics when examining intervention outcomes. Thus, comparing the distance traveled during the 6MWT by a child with cerebral palsy (CP) to a child with typical development may result in different outcomes but will not indicate what intervention strategies should be used for the child with CP. In comparing reference values, therapists must determine whether it is appropriate to set goals for the child with CP to reach the same 6MWT outcome as the child with typical development. Therapists should note that many of the children (43%) in this study were overweight/obese on the basis of BMI. Because BMI is a “screener” for weight category, it would be useful to know a child's body composition to determine weight status, as this may influence 6MWT outcomes. The authors report a small sample size for 11-year-old children, so their values should be interpreted with caution. Also, it may be helpful to know a child's typical physical activity level when interpreting 6MWT findings. Overall, this study provides useful information for therapists using the 6MWT as an outcome measure.