Heredia-Elvar Juan R, Juan-Recio Casto, Prat-Luri Amaya, Barbado David, Vera-Garcia Francisco J
Sports Research Centre, Department of Sport Sciences, Miguel Hernández University of Elche, Alicante, Spain.
Front Physiol. 2021 Oct 22;12:751569. doi: 10.3389/fphys.2021.751569. eCollection 2021.
The lack of training load control, mainly exercise intensity, is one of the main limitations of core stability (CS) programs, which makes the training individualization and the analysis of the dose-response relationship difficult. The objectives of this study were to assess the inter-and intra-rater agreement when using new observational screening guidelines to decide if a core stability exercise represents an adequate training intensity level for a given participant. Besides, the relationship between experts' ratings based on these criteria and pelvic accelerations recorded with a smartphone accelerometer was also analyzed. Ten healthy physically active participants with a smartphone accelerometer placed on their pelvis were video-taped while performing a progression of seven variations of the front bridge, back bridge, side bridge and bird-dog exercises. Two expert and four non-expert raters watched the videos and used the observational screening guidelines to decide for each exercise variation if it represented an adequate training intensity level or not. In order to analyze the inter-and intra-rater agreement, several Kappa (κ) statistics were used. Receiver operating characteristic (ROC) curves to explore if the accelerometry allowed to establish pelvic acceleration thresholds representing the minimum level of exercise intensity for CS training. Cut-off acceleration values were calculated balancing sensitivity (Se) and 1-specifity (1-Sp) indexes (i.e., Youden index) or minimizing 1-Sp. The intra-and inter-rater analysis showed a substantial-high level of agreement with a prevalence-adjusted bias-adjusted Kappa > 0.69. The ROC curves showed that the acceleration thresholds for the bridging exercises were very similar, with global cut-off values of 0.35 m/s (Se = 82%; 1-Sp = 15%) when using the Youden Index and of 0.50 m/s when minimizing 1-Sp (Se = 31%), whilst the bird-dog exercise showed lower cut-off values (Youden Index: 0.21 m/s, Se = 90%, 1-Sp = 16%; minimizing 1-Sp: 0.32 m/s, Se = 40%). Overall, this study provides observational screening guidelines and smartphone accelerometer thresholds to facilitate the decision-making process when setting the intensity of some of the most popular core stability exercises in young physically active individuals.
缺乏训练负荷控制，主要是运动强度控制，是核心稳定性（CS）训练计划的主要局限之一，这使得训练个体化以及剂量反应关系分析变得困难。本研究的目的是评估使用新的观察性筛查指南来判定一项核心稳定性训练对特定参与者而言是否代表足够训练强度水平时，评分者间和评分者内的一致性。此外，还分析了基于这些标准的专家评分与用智能手机加速度计记录的骨盆加速度之间的关系。十名健康且有体育活动习惯的参与者在骨盆处放置智能手机加速度计，在进行前桥、后桥、侧桥和鸟狗式练习的七个变体进阶动作时被录像。两名专家评分者和四名非专家评分者观看视频，并使用观察性筛查指南来判定每个练习变体是否代表足够的训练强度水平。为了分析评分者间和评分者内的一致性，使用了多个卡帕（κ）统计量。绘制受试者工作特征（ROC）曲线，以探究加速度测量法是否能确定代表CS训练最低运动强度水平的骨盆加速度阈值。通过平衡灵敏度（Se）和1-特异性（1-Sp）指数（即约登指数）或最小化1-Sp来计算截断加速度值。评分者内和评分者间分析显示，经患病率调整和偏差调整后的卡帕值>0.69时，一致性水平较高。ROC曲线显示，桥式练习的加速度阈值非常相似，使用约登指数时的总体截断值为0.35米/秒（Se = 82%；1-Sp = 15%），最小化1-Sp时为0.50米/秒（Se = 31%），而鸟狗式练习的截断值较低（约登指数：0.21米/秒，Se = 90%，1-Sp = 16%；最小化1-Sp：0.32米/秒，Se = 40%）。总体而言，本研究提供了观察性筛查指南和智能手机加速度计阈值，以方便在为年轻且有体育活动习惯的个体设定一些最常见的核心稳定性练习强度时的决策过程。
