Arm Cycling Combined with Passive Leg Cycling Enhances VO2peak in Persons with Spinal Cord Injury Above the Sixth Thoracic Vertebra

Abstract

Objective: To test whether passive leg cycling (PLC) during arm cycling ergometry (ACE) affects peak oxygen uptake (VO2peak) differently in individuals with spinal cord injury (SCI) at/above the 6th thoracic vertebra (T6) and below T6. Methods: We conducted a cross-sectional study, analyzed by univariate and multivariate regression models. Between- and within-group differences were examined during (a) ACE only, (b) ACE combined with PLC (ACE-PLC), and (c) ACE combined with functional electrical stimulation cycling (FES hybrid). Fifteen SCI subjects were recruited and grouped according to injury level: at/above T6 (SCI-high, n = 8) or below T6 (SCI-low, n = 7). VO2peak tests during ACE only, ACE-PLC, and FES hybrid were performed in random order on separate days. Results: In the SCI-high group, mean (SD) VO2peak was 19% higher during ACE-PLC than during ACE only [21.0 (3.8) vs 17.7 (5.0) mL·kg-1·min-1; p = .002], while VO2peak during FES hybrid cycling was 16% higher than during ACE-PLC [24.4 (4.1) mL·kg-1·min-1; p = .001]. No significant differences among exercise modalities were found for the SCI-low group. Conclusion: Additional training modalities (eg, PLC) during ACE facilitate exercise in SCI-high individuals, but not to the level of the FES hybrid method. Conversely, additional training modalities may not increase training load in SCI-low individuals.

Keywords: arm ergometry test; ergometry; exercise test; oxygen consumption; spinal cord injury; wheelchair.

Figures

Figure 1.

The based equipment configuration for arm crank ergometry (ACE), arm crank ergometry and passive leg cycling (ACE-PLC), and functional electrical stimulation (FES) hybrid modalities.

Figure 2.

Peak oxygen uptake measured for the SCI-low and SCI-high groups during arm crank ergometry (ACE), arm crank ergometry and passive leg cycling (ACE-PLC), and functional electrical stimulation (FES) hybrid modalities. Data are presented in mean (±SD). VO2peak = peak oxygen uptake. *Significant difference between ACE and ACE-PLC (p ≤ .05). #Significant difference between ACE-PLC and FES hybrid cycling (p ≤ .05). §Significant difference between ACE and FES hybrid cycling (p ≤ .05).