Background This study aimed to determine the threshold of muscle power and strength enhancements that lead to functional gains after exercise intervention in an acute care unit. Methods A total of 302 older patients (intervention: 169, control: 133) from two randomized clinical trials were included (mean age 86.7 years). We measured maximal strength (1RM) and muscle power via a velocity transducer during leg press exercise at 30% and 60% of 1RM. A multicomponent exercise program, including power training, balance, and gait exercises performed over 3 to 6 consecutive days, served as the intervention. We used an anchor-based method to correlate muscle function increases with the Short Physical Performance Battery (SPPB) and gait velocity (GVT) to define clinically meaningful improvements (CMI). Results In the intervention group, marked differences were found in maximal power at 30% of 1RM between SPPB responders and non-responders (relative 83.5% vs. 34.8%; absolute 33.0 vs. 12.8 W; P<0.05) and at 60% of 1RM (relative 61.1% vs. 22.4%; P<0.05). GVT responders demonstrated significantly greater improvements in both relative and absolute maximal power than non-responders at both 30% and 60% of 1RM (P<0.05), as well as greater absolute 1RM gains (21.2 vs. 15.2 kg, P<0.05). CMI for muscle power based on SPPB and GVT ranged from 30.2% to 48.7%, whereas for 1RM, it was 8.2% based on GVT. Conclusion Muscle power gains were most notable in patients with improvements in the SPPB and GVT, highlighting the critical role of muscle power in functional recovery in these patients.

中文翻译：

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确定住院老年患者具有临床意义的肌肉力量增强及其功能相关性


背景 本研究旨在确定在急性监护病房进行运动干预后导致功能增强的肌肉力量和力量增强的阈值。方法 共纳入来自两项随机临床试验的 302 名老年患者 （干预： 169，对照： 133） （平均年龄 86.7 岁）。在腿部推举运动期间，我们通过速度传感器测量了 1RM 的最大力量 （1RM） 和肌肉力量，分别为 1RM 的 30% 和 60%。作为干预措施，包括连续 3 至 6 天进行的力量训练、平衡和步态锻炼。我们使用基于锚的方法将肌肉功能增加与短期体能电池 （SPPB） 和步态速度 （GVT） 相关联，以定义具有临床意义的改善 （CMI）。结果 在干预组中，SPPB 反应者和非反应者在 1RM 的 30% 时的最大功率存在显着差异（相对 83.5% 对 34.8%;绝对 33.0 对 12.8 W;P<0.05）和 1RM 的 60%（相对 61.1% 对 22.4%;P<0.05）。在 1RM 的 30% 和 60% （P<0.05） 下，GVT 应答者在相对和绝对最大功率方面均表现出比无应答者更大的改善，以及更大的绝对 1RM 增益 （21.2 vs. 15.2 kg，P<0.05）。基于 SPPB 和 GVT 的肌肉力量 CMI 在 30.2% 到 48.7% 之间，而对于 1RM，基于 GVT 的 CMI 为 8.2%。结论 SPPB 和 GVT 改善的患者肌肉力量增加最为显着，突出了肌肉力量在这些患者功能恢复中的关键作用。