Predicting oxygen uptake during counterclockwise arm crank ergometry in men with lower limb disabilities

Abstract

Objective: This study was conducted to develop a new equation for predicting oxygen uptake (VO2) during counterclockwise arm crank ergometry (ACE) in men with lower limb disabilities, cross-validate the new equation in a similar group of men, and compare the predictive accuracy of the new equation to previously published equations for clockwise ACE.

Patients: The metabolic responses of 55 men, 17 to 69 years of age, with spinal cord injuries (n = 50) or lower limb fractures (n = 5) were recorded during maximal ACE-graded exercise tests. Participants were volunteers from area hospital rehabilitation centers, and wheelchair sport teams.

Design: Subjects were partitioned by level of injury and randomly assigned to a prediction (PRE) or validation (VAL) group.

Results: No differences were found between the PRE and VAL groups for age, anthropometric or peak exercise variables. Using stepwise regression, a prediction equation (EXP) was derived from the PRE group data. The resulting model: VO2 (mL/min) = 127.06 + 7.201 (Watts) + 4.502 (weight in kg) + 0.033 (Watts2) explained 89.8% of the variance in the PRE group VO2, standard error of estimate (SEE) = 151.9 mL/min. The equation performed similarly in the VAL group (SEE = 144.0mL/min).

Conclusions: In this sample, the EXP equation had less prediction error than equations derived for clockwise ACE. Accuracy was not substantially influenced by level of injury. Comparison of the data to that published previously for clockwise ACE by men with paraplegia suggests greater metabolic economy for counterclockwise as compared with clockwise ACE.