Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania.
University of Virginia, School of Engineering and Applied Science, Virginia.
J Strength Cond Res. 2020 Oct;34(10):2743-2750. doi: 10.1519/JSC.0000000000003794.
Krajewski, KT, Bansbach, HM, McLean, L, McKenzie, C, Rawcliffe, A, Graham, SM, Flanagan, SD, Pourmoghaddam, A, Dettmer, M, and Connaboy, C. Effects of short-term unilateral strength training on measures of postural control when wearing "operationally relevant" backpack loads. J Strength Cond Res 34(10): 2743-2750, 2020-To examine the effects of "operationally relevant" loads on postural stability and to determine the effects of unilateral and bilateral strength training programs on postural stability in healthy, recruit-aged men. Fifteen subjects were randomly assigned to either a unilateral (UL; n = 7) or bilateral (BL; n = 8) strength training group, which performed strength training 3 times a week for 4 weeks. Subjects completed the following pretest and post-test assessments: 1 repetition maximum in bilateral (1RM-BL) and unilateral (1RM-UL) stance positions and bilateral and unilateral balance tasks with eyes open and eyes closed. Balance tasks were performed over 3 loading conditions: body mass (BM), 50% BM, and 70% BM. Sample entropy (SE) and root mean square (RMS) were calculated from the center of pressures collected during each balance assessment. The UL strength training group showed significant improvement after training in both 1RM-UL (p < 0.01) and 1RM-BL (p < 0.01). The BL strength training group only showed significant improvement in 1RM-BL (p = 0.01). There was a significant main effect of load on RMS (p < 0.05) across all balance tasks with RMS increasing with increasing load. Sample entropy was found to decrease with increasing load in the unilateral eyes open and bilateral stance tasks. Significant increases in strength (∼10 to -29%) were observed; however, increased strength alone is not enough to mitigate the effects of load carriage on the postural control, even when training is performed in stance positions that are posturally challenging. Therefore, "operationally relevant" loads negatively impact postural stability in novice load carriers when assessing nonlinear measures.
克拉耶夫斯基、KT、班斯巴赫、HM、麦克林、L、麦肯齐、C、克劳夫利、A、格雷厄姆、SM、弗拉纳根、SD、普尔莫加达姆、A、德特默、M 和康纳博伊、C。穿着“具有实际意义”的背包负载时，短期单侧力量训练对姿势控制测量的影响。J 力量与调理研究 34（10）：2743-2750，2020-为了研究“具有实际意义”的负载对姿势稳定性的影响，并确定单侧和双侧力量训练计划对健康、新兵年龄男性姿势稳定性的影响。15 名受试者被随机分配到单侧（UL；n=7）或双侧（BL；n=8）力量训练组，每周进行 3 次力量训练，持续 4 周。受试者完成了以下预测试和后测试评估：双侧（1RM-BL）和单侧（1RM-UL）站立位置的 1 次重复最大值以及双侧和单侧睁眼和闭眼平衡任务。平衡任务在 3 种负载条件下进行：体重（BM）、50%BM 和 70%BM。在每次平衡评估过程中收集的压力中心的样本熵（SE）和均方根（RMS）。UL 力量训练组在训练后 1RM-UL（p<0.01）和 1RM-BL（p<0.01）均显著提高。BL 力量训练组仅在 1RM-BL 方面表现出显著提高（p=0.01）。在所有平衡任务中，负载对 RMS 有显著的主要影响（p<0.05），随着负载的增加，RMS 增加。在单侧睁眼和双侧站立任务中，发现样本熵随负载的增加而减小。观察到力量的显著增加（约 10%至-29%）；然而，仅增加力量不足以减轻负载对姿势控制的影响，即使在进行姿势具有挑战性的站立位置训练时也是如此。因此，在评估非线性测量时，“具有实际意义”的负载会对新手负载携带者的姿势稳定性产生负面影响。
