Biological Sciences, College of Science, Swansea University, Swansea, Wales, United Kingdom.
PLoS One. 2012;7(2):e31187. doi: 10.1371/journal.pone.0031187. Epub 2012 Feb 17.
Dynamic body acceleration (DBA) has been used as a proxy for energy expenditure in logger-equipped animals, with researchers summing the acceleration (overall dynamic body acceleration--ODBA) from the three orthogonal axes of devices. The vector of the dynamic body acceleration (VeDBA) may be a better proxy so this study compared ODBA and VeDBA as proxies for rate of oxygen consumption using humans and 6 other species. Twenty-one humans on a treadmill ran at different speeds while equipped with two loggers, one in a straight orientation and the other skewed, while rate of oxygen consumption (VO2) was recorded. Similar data were obtained from animals but using only one (straight) logger. In humans, both ODBA and VeDBA were good proxies for VO2 with all r(2) values exceeding 0.88, although ODBA accounted for slightly but significantly more of the variation in VO2 than did VeDBA (P<0.03). There were no significant differences between ODBA and VeDBA in terms of the change in VO2 estimated by the acceleration data in a simulated situation of the logger being mounted straight but then becoming skewed (P = 0.744). In the animal study, ODBA and VeDBA were again good proxies for VO2 with all r(2) values exceeding 0.70 although, again, ODBA accounted for slightly, but significantly, more of the variation in VO2 than did VeDBA (P<0.03). The simultaneous contraction of muscles, inserted variously for limb stability, may produce muscle oxygen use that at least partially equates with summing components to derive DBA. Thus, a vectorial summation to derive DBA cannot be assumed to be the more 'correct' calculation. However, although within the limitations of our simple study, ODBA appears a marginally better proxy for VO2. In the unusual situation where researchers are unable to guarantee at least reasonably consistent device orientation, they should use VeDBA as a proxy for VO2.
动态体加速度 (DBA) 已被用作装备有记录器的动物的能量消耗的替代指标，研究人员从设备的三个正交轴上对加速度（整体动态体加速度--ODBA）进行求和。动态体加速度的矢量 (VeDBA) 可能是一个更好的替代指标，因此本研究比较了 ODBA 和 VeDBA 作为人类和其他 6 种物种耗氧量的替代指标。21 名人类在跑步机上以不同速度跑步，同时配备了两个记录器，一个方向笔直，另一个倾斜，同时记录耗氧量 (VO2)。在动物身上也获得了类似的数据，但只使用了一个（笔直）记录器。在人类中，ODBA 和 VeDBA 都是 VO2 的良好替代指标，所有 r(2) 值均超过 0.88，尽管 ODBA 解释了 VO2 变化的稍多但显著更多（P<0.03）。在模拟记录器笔直安装但随后倾斜的情况下，使用加速度数据估计 VO2 的变化时，ODBA 和 VeDBA 之间没有显著差异（P=0.744）。在动物研究中，ODBA 和 VeDBA 再次是 VO2 的良好替代指标，所有 r(2) 值均超过 0.70，尽管 ODBA 解释了稍多但显著更多的 VO2 变化（P<0.03）。肌肉的同时收缩，为了肢体稳定而以各种方式插入，可能会产生至少部分等同于对 DBA 求和的肌肉耗氧。因此，不能假设对 DBA 进行矢量求和是更“正确”的计算。然而，尽管在我们的简单研究的限制内，ODBA 似乎是 VO2 的稍好替代指标。在研究人员无法保证设备方向至少合理一致的特殊情况下，他们应该使用 VeDBA 作为 VO2 的替代指标。
