Bosch Pamela Rogers, Holzapfel Simon, Traustadottir Tinna
Department of Physical Therapy and Athletic Training, College of Health and Human Services, Northern Arizona University, Flagstaff, AZ.
Department of Physical Activity, Nutrition, and Wellness, School of Nutrition and Health Promotion, Arizona State University, Tempe, AZ.
Arch Phys Med Rehabil. 2015 Oct;96(10):1779-84. doi: 10.1016/j.apmr.2015.04.023. Epub 2015 May 12.
To assess the feasibility of measuring ventilatory threshold (VT) in adults with walking impairments due to stroke. Secondary objectives are to assess reliability of VT over trials; assess whether participants could sustain treadmill walking at VT; and compare mean heart rate during sustained treadmill walking to estimated heart rate reserve (HRR).
Cross-sectional, single-group design.
University research laboratory.
Volunteer sample of adults (N=8) with impaired walking resulting from chronic stroke.
Three submaximal treadmill walking tests on 3 separate days; a 30-minute treadmill walking session on a fourth day.
Gas exchange variables were measured, and 2 independent observers identified VT. Mean heart rate response to treadmill walking at VT was measured and compared with estimated 40% of HRR.
VT was measured successfully in 88% of all trials. There was no difference in VT among trials (P=.17). After multiple imputations to account for 3 missing data points, the intraclass correlation coefficient was .87 (95% confidence interval, .80-.95). All participants were able to walk for 20 minutes at VT. Mean ± SD heart rate during the session was 66.0%±8.0% of estimated maximal heart rate. There was no significant difference between mean heart rate and estimated HRR values (P=.70).
In adults with impaired walking resulting from stroke, VT can be safely measured during submaximal treadmill walking. Participants were able to sustain walking at VT, and this value may provide an appropriate stimulus for aerobic exercise prescription in this population.
评估对因中风导致行走障碍的成年人测量通气阈值（VT）的可行性。次要目的是评估多次测试中VT的可靠性；评估参与者能否在VT强度下持续在跑步机上行走；并比较在跑步机上持续行走期间的平均心率与估计的心率储备（HRR）。
横断面单组设计。
大学研究实验室。
因慢性中风导致行走障碍的成年人志愿者样本（N = 8）。
在3个不同日期进行3次次最大强度跑步机行走测试；在第四天进行30分钟的跑步机行走训练。
测量气体交换变量，由2名独立观察者确定VT。测量在VT强度下跑步机行走时的平均心率反应，并与估计的HRR的40%进行比较。
在所有测试中，88%成功测量到VT。各次测试之间的VT无差异（P = 0.17）。对3个缺失数据点进行多次插补后，组内相关系数为0.87（95%置信区间，0.80 - 0.95）。所有参与者都能够在VT强度下行走20分钟。训练期间的平均心率±标准差为估计最大心率的66.0%±8.0%。平均心率与估计的HRR值之间无显著差异（P = 0.70）。
对于因中风导致行走障碍的成年人，在次最大强度跑步机行走期间可以安全地测量VT。参与者能够在VT强度下持续行走，该值可能为该人群的有氧运动处方提供适当的刺激。
