This study conducted a secondary analysis to objectively measure the effects of modified ride-on cars (MROCs) training in different postures on physical activity (PA) levels in children with motor delays. Data from 39 participants were analyzed in a randomized controlled trial. The participants included those using MROC in standing postures (n = 11, mean age = 22.87 months), MROC in sitting postures (n = 16, mean age = 19.53 months), and a control group that received conventional therapy (n = 12, mean age = 23.30 months). PA intensity was measured using an ActiGraph GT3X on the participants' wrists and right hip at weeks 1, 6, and 12 of the 12-week intervention period. This trial was registered at ClinicalTrials.gov (NCT02527356). The demographic data were similar across the groups. No significant differences were found in the interaction, group, or time effects for any of the positions (p > 0.05). The PA levels were consistent in at least light PA intensity range. MROC training may yield PA levels comparable to those of conventional therapy. Variations in activity and motor impairment severity could affect outcomes. Future studies should investigate factors such as task characteristics, motor delay severity, PA cutoff points, and training dosage that may influence PA intensity.

Keywords: context-focused; modified ride-on car; motor delays; physical activity; randomized controlled trial.

本研究进行了二次分析，旨在客观衡量不同姿势下的改装骑乘式玩具车（MROCs）训练对运动发育迟缓儿童身体活动水平的影响。数据来自一项随机对照试验中的39名参与者。参与者的分组包括使用站立姿势的MROC（n = 11，平均年龄为22.87个月），使用坐姿的MROC（n = 16，平均年龄为19.53个月）和接受传统治疗的对照组（n = 12，平均年龄为23.30个月）。在为期12周的干预期间的第一、第六和第十二周，通过ActiGraph GT3X设备分别佩戴在参与者的手腕和右侧臀部来测量身体活动强度。该试验已在ClinicalTrials.gov上注册（NCT02527356）。各组的人口统计数据相似。对于任何位置，在交互作用、组别或时间效应方面均未发现显著差异（p > 0.05）。在至少轻度的身体活动水平范围内，身体活动水平保持一致。MROC训练可能产生与传统治疗相当的身体活动水平。活动和运动障碍的严重程度的变化可能会影响结果。未来的研究应探讨可能影响身体活动强度的因素，如任务特征、运动发育迟缓的严重程度、身体活动截止点以及训练剂量。

关键词：情境聚焦；改装骑乘式玩具车；运动发育迟缓；身体活动；随机对照试验。