6-minute walk test helps predict walking activity for stroke survivors

A cross-sectional analysis of two trials found that the six-minute walk test was the strongest predictor of walking activity for stroke survivors.

Lead researcher George D. Fulk, PhD, of Clarkson University in Potsdam, New York, and colleagues published their results online in Stroke on Jan. 5.

The researchers evaluated 441 adults who survived a stroke and enrolled in the LEAPS (Locomotor Experience Applied Post-Stroke) and FASTEST (Functional Ambulation: Standard Treatment vs Electrical Stimulation) trials. The participants could walk at least 10 meters with at most maximal assistance and had a gait speed of less than 0.80 m/s at baseline.

Both trials used an activity monitor to measure comfortable gait speed, fast gait speed, six-minute walk test, lower extremity Fugl Meyer, Berg Balance scale, SIS-mobility, SIS-participation, functional ambulation category, mini mental state exam, age, sex, marital status and average steps per day.

For this analysis, the researchers developed analogous functional walking categories based on participants’ daily walking activity. They considered walking activity of 100 to 2,499 steps per day as household ambulatory (the home group), walking activity of 2,500 to 4,999 steps per day as a most limited community ambulatory (the most limited group), walking activity of 5,000 to 7,499 steps per day as a least limited community ambulatory (the least limited group) and walking activity 7,500 or more steps per day as an unlimited community ambulatory (the full community group).

The mean age of participants was 61.4 years old and the mean comfortable gait speed was 0.6 m/s. In addition, 49 percent of participants were female and 80 percent were independent ambulators.

Of the participants, 43.08 percent were household ambulators, 30.39 percent were most limited community ambulators, 14.29 percent were least limited community ambulators and 12.24 percent were unlimited community ambulators.

Based on a model, the researchers found that a combination of walking endurance, balance and motor function were the strongest predictors of community walking activity. They added that walking endurance and motor function helped discriminate between home and community walking activity and limited and unlimited community walking ambulators and that balance helped discriminate between home and community ambulators.

For instance, a comfortable gait speed of 0.49 m/s discriminated between home and community and a comfortable gait speed of 0.93 m/s discriminated between limited community and full community ambulators.

The researchers also found that measuring walking endurance with the 6-minute walk test was the strongest individual predictor of community walking activity. For instance, a six-minute walking distance of 205 meters or longer discriminated between home and community ambulators, while a distance of 288 meters or longer discriminated between limited and unlimited community ambulators.

They said the six-minute walk test is effective because it measures functional walking endurance and is also related to other body structure/function, activity and participation constructs.

The analysis had a few limitations, according to the researchers, including that the model did not account for balance, motor function and other factors that play a role in community mobility. They also noted this was a secondary analysis of data from two different studies.

“Walking endurance, motor function, and balance play an important role in home and community walking activity post-stroke,” the researchers wrote. “Rehabilitation interventions that target these areas may be beneficial for people with stroke in order to improve their ability to walk in their community. Although [comfortable gait speed] can predict home and community ambulators, cutoff values commonly used to discriminate between home and community ambulators may overestimate actual walking activity.”