Which method should be chosen to estimate the oxygen cost of walking in post-stroke individuals?

The oxygen cost of walking (Cw) represents the energy expenditure involved in walking, which is a major concern when quantifying physical activity in stroke. Recent studies have reported that Cw may be estimated accurately with a prediction equation using the self-self-selected walking speed (S_free).

To evaluate the validity of Cw estimates according to different modalities of S_free measurements (10-m walking test, 6-minute walking test, GaitRite system).

Twenty-one stroke individuals in subacute phase who were able to walk without human aid were included. Cw was estimated from the walking speed measured during a 10-m walking test, a 6-minute walking test and a recording on a GaitRite system. The values of the Cw estimates were compared to those measured by a respiratory gas exchange analyzer (Metamax3b).

The findings showed that there is no significant difference between the Cw measured by Metamax3b and the Cw estimates regardless of the modalities used to measure S_free (Fvalue = 0.02; pvalue = 0.99). The mean bias between Cw measured by the Metamax3b and those estimated using the different S_free measurement modalities was less than 2.5 % of the mean Cw value. Test retest reliability was excellent with an intraclass correlation coefficient higher than 0.95.

in stroke survivors who are able to walk independently without human aid, the use of a 10-m walking test, a 6-minute walking test or a GaitRite recording can be considered validated for estimating Cw.