Institute of Sport and Recreation Research New Zealand, School of Sport and Recreation, AUT University, Auckland, New Zealand.
J Strength Cond Res. 2010 Feb;24(2):422-9. doi: 10.1519/JSC.0b013e3181c7c6b9.
The primary purpose of this study was to determine whether a range of static core stability (CS) measures could distinguish shoulder press performance in unstable vs. stable conditions. Thirty resistance-trained men gave informed consent to participate in this study. One-repetition maximum strength (from < 6 repetitions) was predicted in the seated shoulder dumbbell press performed in unstable (Swiss ball[SB]) and stable (back-support bench) environments. Three CS muscle endurance tests were performed, with 4 CS ratios also calculated. The degree of strength decrement, referred to as the instability strength level (ISL), was calculated by dividing the predicted 1RM Unstable score by the 1RM Stable score. All subjects were categorized as high (ISL > 0.90), moderate (0.85 < or = ISL < or = 0.90), or low (ISL < 0.85). Between-group differences for the high- and low-ISL groups were assessed using analysis of variance and effect sizes. Pearson product moment correlations were then performed to examine the relationships between the CS measures and the ISL for the entire group. No significant between-group differences (p = 0.132-0.999) or large effect sizes were observed for any of the CS measures. Trunk flexion endurance was the only CS measure significantly correlated to the ISL (r = 0.477). In line with muscular strength research, these results suggest that CS exhibits relatively high levels of task specificity and that CS performance in static single-joint exercises may not be highly related to that in more dynamic multijoint activities. Core stability training (with or without a SB) may therefore only lead to significant improvements in functional dynamic performance if the postures, mode and velocity of contraction performed in training, are similar to the competitive tasks.
本研究的主要目的是确定一系列静态核心稳定性（CS）测量指标是否可以区分在不稳定和稳定条件下的肩部按压表现。30 名经过阻力训练的男性同意参加这项研究。在不稳定（瑞士球[SB]）和稳定（背部支撑长凳）环境下进行的坐姿哑铃肩推中预测了一次重复最大强度（<6 次重复）。进行了 3 项 CS 肌肉耐力测试，并计算了 4 项 CS 比值。通过将不稳定 1RM 分数除以稳定 1RM 分数，计算出被称为不稳定性强度水平（ISL）的力量下降程度。所有受试者均被归类为高（ISL > 0.90）、中（0.85 < ISL < = 0.90）或低（ISL < 0.85）。使用方差分析和效应量评估高和低 ISL 组之间的组间差异。然后进行 Pearson 产品矩相关分析，以检查整个组的 CS 测量值与 ISL 之间的关系。对于任何 CS 测量值，都没有观察到组间差异（p = 0.132-0.999）或大的效应量。躯干屈伸耐力是唯一与 ISL 显著相关的 CS 测量值（r = 0.477）。与肌肉力量研究一致，这些结果表明 CS 表现出相对较高的任务特异性，并且在静态单关节运动中的 CS 表现可能与更动态的多关节活动没有高度相关性。如果在训练中执行的姿势、模式和收缩速度与竞技任务相似，那么核心稳定性训练（带或不带 SB）可能只会导致功能性动态表现的显著改善。
