Division of Developmental-Behavioral Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
Division of Biokinesiology and Physical Therapy, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA 90089, USA.
Sensors (Basel). 2024 Jul 9;24(14):4436. doi: 10.3390/s24144436.
Lack of physical activity (PA) at a young age can result in health issues. Thus, monitoring PA is important. Wearable accelerometers are the preferred tool to monitor PA in children. Validated thresholds are used to classify activity intensity levels, e.g., sedentary, light, and moderate-to-vigorous, in ambulatory children. No previous work has developed accelerometer thresholds for infancy (pre-ambulatory children). Therefore, this work aims to develop accelerometer thresholds for PA intensity levels in pre-ambulatory infants. Infants (n = 10) were placed in a supine position and allowed free movement. Their movements were synchronously captured using video cameras and accelerometers worn on each ankle. The video data were labeled by activity intensity level (sedentary, light, and moderate-to-vigorous) in two-second epochs using observational rating (gold standard). Accelerometer thresholds were developed for acceleration and jerk using two optimization approaches. Four sets of thresholds were developed for dual (two ankles) and for single-worn (one ankle) accelerometers. Of these, for a typical use case, we recommend using acceleration-based thresholds of 1.00 m/s to distinguish sedentary and light activity and 2.60 m/s to distinguish light and moderate-to-vigorous activity. Acceleration and jerk are both suitable for measuring PA.
缺乏年轻时的身体活动 (PA) 可能导致健康问题。因此，监测 PA 很重要。可穿戴加速度计是监测儿童 PA 的首选工具。验证过的阈值可用于分类活动强度水平，例如，久坐、轻度和中等到剧烈活动，在活动的儿童中。以前没有为婴儿期（非活动儿童）开发加速度计阈值的工作。因此，这项工作旨在为非活动婴儿的 PA 强度水平开发加速度计阈值。将婴儿（n = 10）置于仰卧位置并允许自由移动。使用视频摄像机和佩戴在每个脚踝上的加速度计同步捕捉他们的运动。使用观察评分（金标准）将视频数据标记为活动强度水平（久坐、轻度和中等到剧烈），每两秒钟一个时间段。使用两种优化方法为加速度和急动度开发了加速度计阈值。为双（两个脚踝）和单穿（一个脚踝）加速度计开发了四组阈值。在这些中，对于典型的用例，我们建议使用基于加速度的阈值 1.00 m/s 来区分久坐和轻度活动，以及 2.60 m/s 来区分轻度和中等到剧烈活动。加速度和急动度都适用于测量 PA。
