PREDICTING OXYGEN-UPTAKE DURING COUNTERCLOCKWISE ARM CRANK ERGOMETRY IN MEN WITH LOWER-LIMB DISABILITIES

Objective: This study was conducted to develop a new equation for pred icting oxygen uptake (VO2) during counterclockwise arm crank ergometry (ACE) in men with lower limb disabilities, cross-validate the new equ ation in a similar group of men, and compare the predictive accuracy o f 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) wer e 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. Res ults: 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 (weigh t in kg) + 0.033 (Watts(2)) explained 89.8% of the variance in the PRE group VO2, standard error of estimate (SEE) = 151.9mL/min. The equati on performed similarly in the VAL group (SEE = 144.0mL/min). Conclusio ns: In this sample, the EXP equation had less prediction error than eq uations derived for clockwise ACE. Accuracy was not substantially infl uenced by level of injury. Comparison of the data to that published pr eviously for clockwise ACE by men with paraplegia suggests greater met abolic economy for counterclockwise as compared with clockwise ACE. (C ) 1995 by the American Congress of Rehabilitation Medicine and the Ame rican Academy of Physical Medicine and Rehabilitation