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Quantifying Step Count and Oxygen Consumption with Portable Technology during the 2-Min Walk Test in People with
1Department of Counseling, Health & Kinesiology, Texas A&M University-San Antonio, 1 University Way, San Antonio, TX 78224, USA.
Sensors (Basel, Switzerland)
|April 3, 2021
Summary
This study measured step counts and oxygen consumption during the 2-minute walk test (2MWT) for individuals with lower-limb amputations (LLA). The Garmin vivofit3 wrist and StepWatch ankle monitors showed the best accuracy for step counts in LLA.
Area of Science:
- Rehabilitation Medicine
- Biomedical Engineering
- Exercise Physiology
Background:
- The 2-minute walk test (2MWT) is a functional mobility assessment.
- Step counts and oxygen consumption during the 2MWT in individuals with lower-limb amputations (LLA) are not well-documented.
- Accurate measurement of these parameters is crucial for assessing functional capacity in LLA.
Purpose of the Study:
- To determine step counts and oxygen consumption during the 2MWT in individuals with LLA.
- To evaluate the accuracy of various activity monitors for measuring steps during the 2MWT in LLA.
- To explore differences in these measures based on sex and amputation level.
Main Methods:
- Thirty-five participants with LLA performed the 2MWT.
- Activity monitors (ActiGraph, Garmin vivofit3, modus StepWatch) were worn on the wrist and ankle.
- A portable oxygen analyzer measured oxygen consumption (VO2).
- Step counts were compared between monitors and hand counts.
Main Results:
- The modus StepWatch (ankle) and Garmin vivofit3 (wrist) demonstrated the least error and highest accuracy for step counts.
- No significant differences in distance, VO2, or heart rate were found between sexes or amputation levels.
- Females took more steps than males (p=0.034); transfemoral amputations had fewer steps than transtibial (p=0.023).
- Average VO2 during the 2MWT was 8.9 ± 2.9 mL/kg/min.
Conclusions:
- The Garmin vivofit3 (wrist) and modus StepWatch (ankle) are accurate activity monitors for step counts during the 2MWT in LLA.
- While sex and amputation level influenced step count, they did not significantly impact distance, VO2, or heart rate.
- The measured oxygen consumption suggests the 2MWT may not represent moderate-intensity activity for all individuals with LLA, potentially due to submaximal effort.
