Background

Frailty syndrome is characterized by a marked reduction in physiological reserves and a clinical state of vulnerability to stress. Torque complexity analysis could reveal changes in the musculoskeletal systems that are the result of having the syndrome.

Objective

The aim of this study was to evaluate the complexity of submaximal isometric knee extensor torque in frail, pre-frail, and non-frail older adults. A secondary aim was to analyze the torque complexity behavior in different force levels in each group.

Methods

A cross-sectional study was conducted. Forty-two older adults were divided into three groups: non-frail (n = 15), pre-frail (n = 15), and frail (n = 12). The data collected included body composition, five times sit-to-stand test, walking speed, and isometric knee extensor torque at 15, 30, and 40% of maximal voluntary contraction. The knee extensor torque variability was evaluated by coefficient of variation, and the torque complexity was evaluated by approximate entropy and sample entropy.

Results

The frail group presented a reduction in body mass and peak torque value compared to the non-frail group. Also, the frail group showed worse physical performance (on the five times sit-to-stand test and walking speed) compared to the pre-frail and non-frail groups. In addition, the frail older adults showed reduced torque complexity compared to the non-frail group. Finally, the association between torque complexity and force levels remained similar in all groups.

Conclusion

Torque complexity is reduced in the presence of frailty syndrome.

中文翻译：

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虚弱综合征患者膝关节伸肌扭矩的复杂性：一项横断面研究。

背景

衰弱综合症的特征是生理储备显着减少和易受压力影响的临床状态。扭矩复杂性分析可以揭示因患有该综合征而导致的肌肉骨骼系统的变化。

客观的

本研究的目的是评估虚弱、虚弱前和非虚弱老年人的次最大等长膝关节伸肌扭矩的复杂性。第二个目标是分析每组不同力水平下的扭矩复杂性行为。

方法

进行了一项横断面研究。42 名老年人被分为三组：非虚弱组（n  = 15）、虚弱前期组（n  = 15）和虚弱组（n  = 12）。收集的数据包括身体成分、五次坐站测试、步行速度以及最大自主收缩的 15%、30% 和 40% 时的等长膝伸肌扭矩。通过变异系数评价膝伸肌扭矩变异性，通过近似熵和样本熵评价扭矩复杂度。

结果

与非虚弱组相比，虚弱组的体重和峰值扭矩值有所减少。此外，与虚弱前组和非虚弱组相比，虚弱组表现出更差的身体表现（五次坐站测试和步行速度）。此外，与非虚弱组相比，虚弱的老年人表现出较低的扭矩复杂性。最后，所有组中扭矩复杂性和力水平之间的关联保持相似。

结论

存在虚弱综合症时，扭矩复杂性会降低。