Article

The objective of this study was to determine, and compare, the utility of the
6-min walk test (6 MWT) and self-selected walking speed over 15 m as proxies for
the assessment of energy expenditure during gait in individuals with lower-limb
amputation. Patients with unilateral, transfemoral amputation (n=6) and patients
with unilateral, transtibial amputation (n=10) from community-based support
groups participated in this study. Age-matched and body mass index-matched
able-bodied controls (n=28) from a sample of convenience also participated. The
main outcome measures were as follows: (a) distance, heart rate, oxygen
consumption and oxygen cost during the 6 MWT and (b) self-selected walking speed
over 15 m. Oxygen cost did not correlate significantly with self-selected walking
speed over 15 m (rho=-0.329) or average walking speed during the 6 MWT
(rho=-0.350). Significant correlations were not present between oxygen cost and
the walking speed during the 6 MWT (range, mid R:rhomid R:: 0.210-0.531),
although walking speeds at particular times of the 6 MWT demonstrated stronger
correlations than others. Walking speed in the third min of walking during the 6
MWT recorded the strongest correlation with peak oxygen cost (rho=-0.531). The 6
MWT is a submaximal measure in persons with lower-limb amputation. Self-selected
walking speed over 15 m was not an appropriate proxy for the assessment of the
energy cost of gait. Individuals with a lower-limb amputation require
approximately 3 min of continuous walking to re-establish homoeostasis in heart
rate, oxygen consumption and oxygen cost. The nonsignificant correlation between
walking speeds during the 6 MWT and oxygen cost suggest that the 6 MWT can
provide an indication of oxygen cost, but caution should be exercised when using
it as a sole proxy for the measurement of oxygen cost in individuals with
lower-limb amputation.

Langue : ANGLAIS