Gerontology Department, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Frailty in Ageing Research Department, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels, Belgium; Geriatrics Department, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, B-1090 Brussels, Belgium.
Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
Exp Gerontol. 2018 Oct 1;111:65-70. doi: 10.1016/j.exger.2018.07.004. Epub 2018 Jul 9.
Muscle fatigability can be measured based on sustained handgrip performance, but different grip strength devices exist and their relationship to frailty remains unclear. We aimed to compare muscle fatigability obtained by Martin Vigorimeter and Jamar Dynamometer in older women across levels of frailty.
53 community-dwelling women living in Greece (63-100 y), categorized according to tertiles on the Frailty Index score (FI) as: low-frail (FI < 0.19), intermediate-frail (FI 0.19-0.36), and high-frail (FI > 0.36). Fatigue resistance (FR, time for maximal grip strength to decrease to 50% during sustained contraction) was measured with both Martin Vigorimeter and Jamar Dynamometer, and grip work (GW, reflecting the area under the time-force curve) was calculated.
FR, when measured with the Martin Vigorimeter, was approximately double in low-frail (44.3 ± 24.6 s) compared to high-frail participants (23.9 ± 12.7 s, p = 0.011), whereas FR was similar across frailty groups when measured with the Jamar Dynamometer. In logistic regression models, FR (OR = 0.94 [0.90-0.99]) and GW (OR = 0.90 [0.82-0.99]) were significantly related to high frailty when measured with the Martin Vigorimeter but not when measured with Jamar Dynamometer. There is a significantly proportional difference in FR measured with both devices (R = 0.364, p < 0.001), highlighting that the longer the participant could sustain the FR test, the higher the difference in FR measured with both devices.
Our results suggest that the Martin Vigorimeter is a more appropriate handgrip device compared with the Jamar Dynamometer to assess muscle fatigability for older women across levels of frailty. When measured with the Martin Vigorimeter, high-frail participants show twice the level of fatigability compared to low-frail, whereas no difference was observed when using the Jamar Dynamometer. Older participants might stop the FR test prematurely when using the Jamar Dynamometer, before muscle fatigue is reached, indicating that the Jamar Dynamometer is unable to identify those participants with higher levels of muscle endurance. Martin Vigorimeter assessed muscle fatigability might be a good additional marker to include in frailty tools.
肌肉疲劳性可通过持续握力表现来测量，但握力计的种类不同，其与虚弱的关系尚不清楚。我们旨在比较 Martin Vigorimeter 和 Jamar Dynamometer 在不同虚弱程度的老年女性中获得的肌肉疲劳性。
53 名居住在希腊的社区女性（63-100 岁），根据虚弱指数（FI）的三分位数进行分类：低虚弱（FI<0.19）、中等虚弱（FI 0.19-0.36）和高虚弱（FI>0.36）。使用 Martin Vigorimeter 和 Jamar Dynamometer 测量疲劳抵抗力（FR，最大握力在持续收缩过程中下降到 50%所需的时间），并计算握力功（GW，反映时间-力曲线下的面积）。
当使用 Martin Vigorimeter 测量时，低虚弱组的 FR（44.3±24.6s）几乎是高虚弱组的两倍（23.9±12.7s，p=0.011），而当使用 Jamar Dynamometer 测量时，FR 在虚弱组之间相似。在逻辑回归模型中，当使用 Martin Vigorimeter 测量时，FR（OR=0.94[0.90-0.99]）和 GW（OR=0.90[0.82-0.99]）与高虚弱显著相关，但当使用 Jamar Dynamometer 测量时则不相关。两种设备测量的 FR 存在显著的比例差异（R=0.364，p<0.001），这表明参与者能够维持 FR 测试的时间越长，两种设备测量的 FR 差异就越大。
我们的结果表明，与 Jamar Dynamometer 相比，Martin Vigorimeter 是一种更适合评估不同虚弱程度老年女性肌肉疲劳性的握力计。当使用 Martin Vigorimeter 测量时，高虚弱组的疲劳性是低虚弱组的两倍，而使用 Jamar Dynamometer 时则没有差异。当使用 Jamar Dynamometer 时，较年长的参与者可能会在达到肌肉疲劳之前过早停止 FR 测试，这表明 Jamar Dynamometer 无法识别那些肌肉耐力较高的参与者。使用 Martin Vigorimeter 评估肌肉疲劳性可能是虚弱工具的一个很好的补充标志物。
