The infinity test: a novel 3-minute all-out wheelchair field test for estimating VO₂peak in individuals with paraplegia.

Authors

Clément Leveque, Sigrid Theunissen, Mikel Ezquer, Elise Hayot, Kate Lambrechts, Costantino Balestra

Published in

Spinal cord. Jul 18, 2026. Epub Jul 18, 2026.

Abstract

Methodological cross-sectional validation study with external validation.
To develop and externally validate the Infinity Test, a 3-min all-out field protocol performed in the participant's own wheelchair with enforced synchronous propulsion, designed to estimate peak oxygen uptake (VO₂peak) in manual wheelchair users with chronic paraplegia.
Environmental, Occupational, Aging (Integrative) Physiology Laboratory, Haute École Bruxelles-Brabant (HE2B), Brussels, Belgium.
Seventeen manual wheelchair users with chronic paraplegia completed both the Infinity Test and a laboratory arm-crank graded exercise test in counterbalanced order (development cohort). An independent cohort of 11 participants completed the Infinity Test only (external validation cohort). Breath-by-breath VO₂ was measured using a validated portable metabolimeter. Laps·min^-1 were derived from manual lap counting using standardized rounding rules and converted to predicted VO₂peak via a linear no-intercept model. Agreement with laboratory VO₂peakErgo was assessed using ICC, Bland-Altman analysis, Passing-Bablok regression, and ordinary least-products regression. Internal validity was evaluated using leave-one-out cross-validation; external validity via correlation and mean absolute error (MAE).
Infinity Test VO₂peak∞ did not differ from laboratory VO₂peakErgo (mean bias + 25 mL·min^-1, 95% CI-360 to + 410; p = 0.89; ICC = 0.89, 95% CI 0.73-0.96). No fixed or proportional bias was detected. The no-intercept equation (VO₂peak∞ = 461 × laps·min^-1) explained 61% of variance in the development cohort (SEE = 517 mL·min^-1). External validation showed R² = 0.70 and MAE = 322 mL·min^-1 (14.8% of the mean). The protocol was well tolerated and completed in < 5 min including setup.
The Infinity Test provides a feasible and ecologically valid field protocol for estimating VO₂peak in individuals with paraplegia. Its combination of predictive accuracy, operational simplicity, and use of personal wheelchairs, together with an open-source digital toolkit (interactive nomogram and automated clinical reporting), may support its integration into rehabilitation, high-performance, and community-based practice.

PMID:
42471492
Bibliographic data and abstract were imported from PubMed on 19 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.