Reliability of a recumbent stepper submaximal exercise test after traumatic brain injury

ABSTRACT

Purpose

To determine the test–retest reliability of a total body recumbent stepper (TBRS) submaximal exercise test and to examine its relationship with other measures throughout the International Classification of Functioning that are indicative of overall health in individuals with traumatic brain injury (TBI).

Methods

Twenty-three ambulatory individuals with severe, chronic (>6 mos) TBI completed a TBRS submaximal exercise test, 6-minute walk test (6MWT), and Mayo Portland Adaptability Inventory (MPAI-4) at initial testing. A repeat TBRS submaximal exercise test was conducted 4–7 days later. Estimated peak oxygen consumption (VO₂) was calculated from the TBRS submaximal exercise test using the VO₂ prediction equation. Average daily step count was collected by an activity monitor for the 4–7-day period between tests.

Results

Test-retest reliability was good (ICC_3,1 = 0.79, p < .001). The difference between the tests was 0.46 ml・kg⁻¹・min⁻¹ which was not statistically different. Neither the 6MWT distance nor gait speed are related to the TBRS-estimated peak VO₂. The MPAI-4 total score and adjustment subscale each had a fair relationship with the TBRS-estimated peak VO₂ (r = −0.41, p = .05; rs = −0.41, p = .05, respectively).

Conclusion

These data suggest that the TBRS submaximal exercise test may be a reliable measure to estimate peak VO₂ in ambulatory adults with chronic severe TBI.

KEYWORDS:

• Submaximal exercise test
• cardiorespiratory fitness
• recumbent stepper
• traumatic brain injury

Acknowledgments

The authors would like to thank all the TBI survivors who participated in this study and their families.

Disclosure of potential conflicts of interest

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by the University of Indianapolis In Query Grant [Index # 525017].