Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences, Blacksburg, VA, USA.
Med Sci Sports Exerc. 2009 Jul;41(7):1488-93. doi: 10.1249/MSS.0b013e31819bd4bd.
Obesity is associated with an increased risk of falls and injury. Weight loss and strength training can be beneficial to balance, but knowing which is more beneficial would lead to interventions designed for maximal benefit in balance.
The goal of this study was to investigate the relative effects of weight loss and strength training on balance recovery using an ankle strategy.
We used a combination of experimental testing and forward dynamic simulations. Nine male subjects (body mass index = 30.1-36.9 kg x m(-2)) were released from a forward lean and attempted to recover balance using an ankle strategy. Lean angle was increased until subjects required a step or hip flexion to recover balance. The maximum lean angle, thetamax, was used as the measure of balance recovery capability. Experimental data served as inputs to an inverted pendulum model of balance recovery. Multiple simulations were performed to determine the effects of weight and strength on thetamax.
Both strength training and weight loss increased thetamax. Comparing the percent changes in weight and strength required to increase thetamax, a targeted amount revealed differences in intervention potency. For example, to increase thetamax by 1 degree, an 8.6 +/- 0.8% decrease in weight or 15.3 +/- 1.1% increase in strength was required. The differences in efficacy between the interventions became more apparent as larger increases in thetamax were targeted.
Balance recovery can improve with weight loss or strength gain, but a smaller amount of weight loss is needed than strength gain for a targeted improvement in balance recovery. This suggests that weight loss is a more potent intervention than strength training in improving balance recovery using an ankle strategy.
目的：本研究旨在通过踝关节策略探究减肥和力量训练对平衡恢复的相对影响。
方法：我们采用实验测试和正向动力学模拟相结合的方法。9 名男性（体重指数为 30.1-36.9kg/m²）前倾后，试图通过踝关节策略恢复平衡。增加前倾角度，直到受试者需要迈步或髋关节屈曲来恢复平衡。最大前倾角度 thetamax 作为平衡恢复能力的衡量指标。将实验数据作为平衡恢复的倒立摆模型的输入。进行多次模拟，以确定体重和力量对 thetamax 的影响。
结果：力量训练和减肥都增加了 thetamax。比较增加 thetamax 所需的体重和力量的百分比变化，靶向量揭示了干预效果的差异。例如，要使 thetamax 增加 1 度，需要减少 8.6±0.8%的体重或增加 15.3±1.1%的力量。随着靶向 thetamax 的增加，干预措施之间的疗效差异变得更加明显。
结论：平衡恢复能力可以通过减肥或力量增强来提高，但为了有针对性地提高平衡恢复能力，所需的体重减轻量比力量增加量要少。这表明，与力量训练相比，减肥是改善踝关节策略下平衡恢复的更有效干预措施。
